So my bike, a 2006 88" EFI Softail Fatboy, now at 29k miles, had vibration issues while on a long trip from Wisconsin. First a little history. The bike was running perfectly fine around my area until my local dealership in Madison installed an S&S hydraulic chain tensioner upgrade 10 months ago, when I IMMEDIATELY noticed a bit of vibration that wasn't there before (like, out of the parking lot noticed it). Not terrible, just made my hands numb after 20 miles or so, it just felt different and I knew with no cam or other changes the bike SHOULD run the same. However they couldn't find anything, and ended up tuning the vibration out, which smoothed things out until about 65mph and above, which made it tolerable in my area. However after thinking about it, I doubt they spent 10 hours taking everything apart a 2nd time to actually check their work. That's a lot of company time.
So onto my story. From Wisconsin I made it to Kansas when I started noticing vibration, and after hitting Amarillo TX and west to Albuquerque NM the vibration was getting worse to the point I aborted my run. I was stopping every 30 miles or so to let the bike cool because at the time I thought it was heat related as it was 100 degrees in the area at the time. After many miles of experimentation I found it wasn't the speed I was being forced to run (typically 85mph posted EVERYWHERE) as it was the rpms. Usually around 2800-3000 rpms is when the vibration was getting pretty intense, feeling it most in the foot pegs and seat, less in the handlebars. The vibration when starting the day cold would be fairly minimal up until about 5 to 7 miles (when the engine got up to temperature, which is why I thought it was temperature related). However, in Wisconsin the elevation is about 1,000 feet....and in Texas and New Mexico it was about 5,000 to 7,000 feet. Now I want to imagine the EFI injection SHOULD compensate for this. It definitely wasn't in the wheels, as the vibration immediately vanished upon pulling in the clutch. Seems everybody's first thought was an unbalanced wheel everywhere I went.
Dealership in Amarillo TX found a loose top mount bolt loose, but that ended up changing nothing and onward west I went into Albuquerque dealership, who gave me a couple possibilities- both rather expensive, their first thought was the internal balancers, or the compensator. I have since scratched off both these as possibilities as I have no rattling in the primary for a compensator, and I'm told the internal balancers would make the bike vibrate ALL the time, immediately upon starting and all. Not to mention that it would be unaffected by elevation.
So onto my elevation subject. Upon abandoning my run west I headed straight north into Colorado, which was a great reprieve of the 85mph speed limits and let me take it easier at the slower mountain road speeds. Despite the elevation of 10,000 feet the bike was performing well at lower rpms and speeds of under 60mph. The local dealership, Avalanche, was absolutely fantastic btw as they were the first dealership to really listen to what I was saying, but again came up empty on a solution other that for me to trade in my bike :hyst: . I entered South Dakota and started making my way east on the interstate at 80mph, at the time trying to make miles for the day. However at 80mph, the vibration was almost tolerable. Not the having to stop every 30 miles it was in the south. And as I went further and further east through Minnesota the vibration lessened, effectively back to normal as it was back home.....and that's when I noted the elevation of 1700 feet and dropping.
So when I got into Wisconsin again after over 4,000 miles, I pulled the plugs I had just installed before my trip began and I found the rear spark plug was white, and the front was a tannish brown. So the rear is running lean. Now being at high elevation I would think both would be running a bit funky with the thin air, but having one plug vastly different from the other is a big red flag that something is wrong.
I get back home and immediately ride to the dealership that caused the vibration issues in Madison, and the service supervisor is yet again scratching his head. He's thinking it's the compensator and not the internal balancer (thank god it's not the internal balancer) however with only 30k miles he still has his doubts it's the compensator...and I haven't had any compensator rattling issues. I am convinced it's something they messed up when putting in the S&S cam tensioner setup, maybe they didn't line up the rear cam correctly? If I can get them to open it up and check their work without costing me anything that would be nice. I'm thinking of ways for them to do it, I'm considering ordering them to check the crankshaft runout to force them to open it up again. I'd like to know what it is anyways, I forgot to have them check that the first time. Or I may have it dyno tuned somewhere, maybe I'll find answers there?
So full details of my bike, for reference:
88ci engine
6 speed screamin' eagle transmission
Master Tune II tune
S&S intake
V&H ProPipe
203 Screamin Eagle camshafts
I've found the sprocket on the pinion shaft, that is used to time the 2 counter balancers moved on the shaft.
John
You said they originally managed to tune the vibration out when it showed up? Do you have the original tune before they worked on it? How about you download what it's doing now and compare cylinders. It may be possible to determine by timing and AFR changes if the rear cam is off. Ideally you would want the dealer to pull the timing cover and find the problem so you don't get blamed for monkeying with it and finding an abnormal tune characteristic may be what it takes to get them to check.
As John Sachs says the soft pinion bolt can shear when reused also. Either way, IMO it's look inside time.
Quote from: jsachs1 on July 20, 2022, 01:46:14 PMI've found the sprocket on the pinion shaft, that is used to time the 2 counter balancers moved on the shaft.
John
That was a topic of discussion at the Avalanche dealership in Denver. I didn't fully understand it at the time, but I wrote it off because one, I don't believe it was something affected by the cam tensioner swap job, and it wouldn't be something that comes and goes with elevation. I'll bring it up to my dealership tho, I don't think they thought of it yet. I'm thinking it could be a part of the problem tho, as I could be looking at a couple small problems that are adding up to be a larger problem.
Quote from: kd on July 20, 2022, 01:56:12 PMYou said they originally managed to tune the vibration out when it showed up? Do you have the original tune before they worked on it? How about you download what it's doing now and compare cylinders. It may be possible to determine by timing and AFR changes if the rear cam is off. Ideally you would want the dealer to pull the timing cover and find the problem so you don't get blamed for monkeying with it and finding an abnormal tune characteristic may be what it takes to get them to check.
As John Sachs says the soft pinion bolt can shear when reused also. Either way, IMO it's look inside time.
Couldn't agree more kd, I'm not touching anything so I don't get blamed for a problem that I didn't cause. I don't know what kind of records of tuning the dealership keeps but tuning is definitely on the table. Too bad they don't have a dyno tune there tho. I don't know how to download the tune at all at home, I really should learn how.
Oh btw, I didn't find any head gasket leaks or anything like that in the rear cylinder that would explain the lean condition.
It didn't vibrate before they worked on it.
Now it vibrates immediately after they worked on it.
I'm just throwing spitballs here, but I'm thinking it might be something that happened when they worked on it.
Quote from: Hossamania on July 20, 2022, 02:09:38 PMIt didn't vibrate before they worked on it.
Now it vibrates immediately after they worked on it.
I'm just throwing spitballs here, but I'm thinking it might be something that happened when they worked on it.
EXACTLY MY THOUGHTS! I think the local service manager is tip-toeing around this to avoiding it. I kept bringing this up to the dealership service departments in other states but oh no no no....it's the internal balancer...no no no...it's the compensator. So aggravating when people don't listen to me because I'm just another stupid customer. That's what made Avalanche HD in Denver really nice, they actually listened to me.
I'm not sure how they "tuned" out the vibration, but my guess is it may be off a tooth.
It should be pulled apart and double-checked.
Quote from: SmokyOwl on July 20, 2022, 02:05:00 PMQuote from: kd on July 20, 2022, 01:56:12 PMYou said they originally managed to tune the vibration out when it showed up? Do you have the original tune before they worked on it? How about you download what it's doing now and compare cylinders. It may be possible to determine by timing and AFR changes if the rear cam is off. Ideally you would want the dealer to pull the timing cover and find the problem so you don't get blamed for monkeying with it and finding an abnormal tune characteristic may be what it takes to get them to check.
As John Sachs says the soft pinion bolt can shear when reused also. Either way, IMO it's look inside time.
Couldn't agree more kd, I'm not touching anything so I don't get blamed for a problem that I didn't cause. I don't know what kind of records of tuning the dealership keeps but tuning is definitely on the table. Too bad they don't have a dyno tune there tho. I don't know how to download the tune at all at home, I really should learn how.
Oh btw, I didn't find any head gasket leaks or anything like that in the rear cylinder that would explain the lean condition.
It is possible they tuned one or the other cylinder to balance the firing somewhat. If the tune is real lean on the rear that's a it of a red flag. If it's real lean the fact the tuner left it like that is troubling too. Going on a trip and experiencing elevation could have been fatal.
If you want to try to download a TTS tune you can go to the Master Tune site and download the suite of apps they have. One of them will give you instructions on how to do it and save it for viewing. You can also follow the instructions on interpretation of the saved info. Your dongle might have the original tune in the saved history also for comparison. Who knows, something may show up as way different between the front and rear cylinders. Do a compression check and if they are close their tune should be too. A little different is no biggie and somewhat normal.
BTW You will need the cables Mastertune names but they are Harley and it may even be possible to borrow a set if you know anyone that may use them.
I like kd's idea of doing a compression test, a very simple test to at least start the diagnosis.
A minor difference found in compression, 154psi in the rear, 160psi in the front.
Quote from: SmokyOwl on July 21, 2022, 11:19:09 AMA minor difference found in compression, 154psi in the rear, 160psi in the front.
Not too much difference to worry about. Leads one to think that the cams are not off. Test was done with strong battery, throttle plate held open?
Quote from: Hossamania on July 21, 2022, 11:25:03 AMQuote from: SmokyOwl on July 21, 2022, 11:19:09 AMA minor difference found in compression, 154psi in the rear, 160psi in the front.
Not too much difference to worry about. Leads one to think that the cams are not off. Test was done with strong battery, throttle plate held open?
:crook: Battery is fine, I didn't know about the throttle plate being held open tho :embarrassed: what difference does that make? I'll have to try it again late tonight if it's really important. I did two readings on each cylinder, both had about 1psi in difference after 8 cycles.
I think since the spark plug replacement they've had about 500 miles on them; the rear cylinder looked a touch leaner than the front but it's really difficult to judge with such few miles on them....and I am predispositioned to look for that lean condition too now.
Holding the throttle open (be sure the plate is opening) will raise your compression readings as the cylinders can pull as much air as possible. It may show a greater disparity in readings between cylinders, but will give a true reading.
:agree: Absolutely true.
Going by the motor specs provided, the cranking compression should be about 158 psi, +/- 5 psi.
Assuming the 88 inch is stock compression and head gasket.
88ci engine
6 speed screamin' eagle transmission
Master Tune II tune
S&S intake
V&H ProPipe
203 Screamin Eagle camshafts
So there IS a notable difference between holding the throttle open and not:
Holding the throttle open: Rear- 165psi Front- 162psi, a noticeable difference in the rear cylinder from the previous 154psi reading when not opening the throttle.
I noticed sometimes I would get about a 5psi increase from these findings in both cylinders on occasion, I'm assuming this is from some kind of unique position of the piston in the cylinder when starting to crank or possibly just a glitch reading in my equipment. But other than that I was getting very consistent pressure readings.
I do now recall when talking with the service manager about the sprocket and pinion shaft, I'm pretty sure he mentioned that it cannot move out of position because it's locked in place with a keyway. Maybe he was referring to something else, my mind gets fuzzy in the memories. I'm unfamiliar with these components and what they do, I tried looking them up but I'm still a little confused. It doesn't look like a part that would be touched when doing a cam tensioner swap?
Quote from: SmokyOwl on July 22, 2022, 01:02:06 PMSo there IS a notable difference between holding the throttle open and not:
Holding the throttle open: Rear- 165psi Front- 162psi, a noticeable difference in the rear cylinder from the previous 154psi reading when not opening the throttle.
I noticed sometimes I would get about a 5psi increase from these findings in both cylinders on occasion, I'm assuming this is from some kind of unique position of the piston in the cylinder when starting to crank or possibly just a glitch reading in my equipment. But other than that I was getting very consistent pressure readings.
I do now recall when talking with the service manager about the sprocket and pinion shaft, I'm pretty sure he mentioned that it cannot move out of position because it's locked in place with a keyway. Maybe he was referring to something else, my mind gets fuzzy in the memories. I'm unfamiliar with these components and what they do, I tried looking them up but I'm still a little confused. It doesn't look like a part that would be touched when doing a cam tensioner swap?
I feel that some on this thread are missing what I posted. There's a gear on the flywheels ,that is in the area of the flywheel bearing race on the right side of the flywheels (pinion shaft extends from it). It is a pressed on gear, with a timing mark on it. That mark is used to coincide with (timing) the 2 counter balancers, which also has the mark on each of them. That gear (on the pinion side of the flywheels, can move out of time, which will let the counter balancers go out of time.
John
If that is the case, it is just a coincidence and bad luck that it happened about the same time as the tensioners were changed? It doesn't sound like it happened due to anything the dealer did. Am I reading that right, John?
Yes I believe that was exactly what the manager and I were discussing, and he said that it was impossible because there was either a flat spot or keyway that made misalignment impossible. However if by chance it COULD spin that could be the case if they had hit it with something maybe? I suppose it is a possibility somehow if people are talking about it.
Quote from: SmokyOwl on July 22, 2022, 04:47:57 PMYes I believe that was exactly what the manager and I were discussing, and he said that it was impossible because there was either a flat spot or keyway that made misalignment impossible. However if by chance it COULD spin that could be the case if they had hit it with something maybe? I suppose it is a possibility somehow if people are talking about it.
The tell tale of out of time cam(s) is usually a wide compression variance. That doesn't seem to be the case now that you've done the easy non invasive compression test. I would say that John has nailed it. He very knowledgeable and usually knows what he's talking about too. :wink:
Quote from: SmokyOwl on July 22, 2022, 04:47:57 PMYes I believe that was exactly what the manager and I were discussing, and he said that it was impossible because there was either a flat spot or keyway that made misalignment impossible. However if by chance it COULD spin that could be the case if they had hit it with something maybe? I suppose it is a possibility somehow if people are talking about it.
IMO, he's wrong. That gear can spin, I had a bike in for work, in April with that problem. Balancers off by 2 1/2 teeth (I replaced the wheels, with a known good set, Ok by customer)( there's a shop in So. Fla. that claims they repair that problem), and I've also found on another job, a loose pinion bearing race. I'm sure you can get more info from Dark Horse Crank Works.
John
I'm sorry, but I'm seeing over and over that the gear on the pinion shaft can't rotate. I'm seeing many pictures where there's a flat section on the shaft so the gear can only go on one way. THIS IS NOT MY PICTURE, it's just for reference on somebody else's 88 twin cam that had some scoring issues and antoher where they're putting on an S&S gear set. You can clearly see the flat area where the sprocket would go on, and it cannot rotate around the shaft? I'm assuming this is what the dealership service manager was referring to. So if this sprocket cannot go on in the wrong position, I'm confused as to what can? Is the entire shaft rotated in the wrong position? I think I need to get on the same page, I'm a little confused as to what's mispositioned. Is the bottom gear mispositioned in the wrong slots of the timing chain?
Pinion shaft.jpg
Pinion Gear.jpg
Do not upload images taken from other websites. Doing this will get you banned. Use an IMG tag instead. - Coyote
You're missing John's point. That's not the balancer sprocket. You have to dig deeper to get there.
(https://hotbike.com/wp-content/uploads/2009/02/0807_hbkp_05_z2Btwin_cam2Btig_weld.jpg)
(https://hotbike.com/wp-content/uploads/2009/02/0807_hbkp_14_z2Btwin_cam2Bb_motor_assembled.jpg)
OK gotcha. So we are talking about splitting the entire case open. I was really hoping to avoid that :banghead: so what I'm seeing from these pictures is an alarmingly thin sprocket that's just pressed in place on the crankshaft. Only being held in place with compression- I'm pretty shocked by this given it's critical component status. Once repositioned, can it be welded into place or anything to prevent it from happening again?
So after admittedly a pretty short period of thought here, is it possible for the mechanic to force the crankshaft to spin a little while the internal balancing chain doesn't move when putting the bolt for the lower sprocket on or off? Does that makes sense? Like if they forgot to put the locking block in the timing chain so stuff didn't move, it started to move and then it's "oh crap I forgot the block". So while the crankshaft rotated for a little bit, that sprocket didn't move and the sprocket got itself misaligned on the crankshaft from the crankshaft turning a little. I'm not sure of how much force it would take to break that rear balancing sprocket loose off the crankshaft in comparison to the torque of breaking the crankshaft end bolt loose or tightening it.
Read the entire article.
Twin Cam B-Motor Balancer Mods (https://hotbike.com/twin-cam-b-motor-balancer-mods/)
A friend of mine had to have this done when his balancers shifted.
Quote from: Hossamania on July 26, 2022, 05:06:32 PMA friend of mine had to have this done when his balancers shifted.
I'm honestly worried about the cost. If the engine has to be cracked open, I might as well have a timken bearing installed. I'm going to guess something like $5,000?
Is there any way tho that a mechanic caused this misalignment? It IS a big coincidence that this happened when they were working on the hydraulic tensioner swap.
Quote from: SmokyOwl on July 26, 2022, 05:58:02 PMIs there any way tho that a mechanic caused this misalignment? It IS a big coincidence that this happened when they were working on the hydraulic tensioner swap.
As you see, the cases have to be split to reach the balancer assembly. You don't split the cases to put in cam chain tensioners.
Sadly it seems an unfortunate coincidence until a deeper investigation gets done.
If that's the problem, fix it properly, or replace the wheels. :banghead:
John
This happened to mine which was caused by over revving, the higher the rpm the worse the vibration was. It still ran good just vibrated so bad it made my hands go numb. I ended up rebuilding the whole engine
Quote from: Robb1178 on August 07, 2022, 07:04:48 AMThis happened to mine which was caused by over revving, the higher the rpm the worse the vibration was. It still ran good just vibrated so bad it made my hands go numb. I ended up rebuilding the whole engine
I was wondering as to the possible cause so it didn't happen again, thanks for the insight. I'm probably going to have the sprocket tig welded in place so it doesn't happen again.
I know this is going to make quite a few people on here groan :emoGroan: , but I've decided to keep it an 88 and not going for a 95 conversion. My reasoning is simply because I don't want to hurt my mileage any more, as I'm currently struggling to get 40mpg, making 200 miles to a tank is really stretching it right now and I don't want it to drop anymore than it already has with the current modifications.
I actually found a, not sure how to describe it, like a duo company that merged... one makes connecting rods and the other makes pistons. And they make new setups for 88 engines in multiple bore-wear sizes. At first I was planning on just upgrading the connecting rods and keeping the same pistons as the compression is quite good right now- thinking why mess with a good thing right? But then it hit me, the moment the pistons are removed- the rings wear grooves are NEVER going to match up again. Which means I have to hone the cylinders and get new piston rings at minimum. Then I thought even with new oem pistons, if the cylinder's are honed then I'll have piston slap and was for a time considering doing the 95 swap until I realized the gas mileage loss. So I think this company with the new piston sizes for honed cylinders fits the bill perfectly for what needs to be done. I'm...a bit of a perfectionist :unsure:
I'm also strongly considering having the compensator drive front sprocket increased by 1 tooth, lowering the full rpm spectrum a little bit for higher top speed and mpgs. I thought about lowering the rear chain sprocket at the transmission until I realized when I would be going the typical 30mph around town if I'm in my usual 3rd gear I would likely be lugging the engine at that point and I rather not be in 2nd gear.
Quote from: SmokyOwl on August 09, 2022, 09:16:13 PMI actually found a, not sure how to describe it, like a duo company that merged... one makes connecting rods and the other makes pistons. And they make new setups for 88 engines in multiple bore-wear sizes.
Well don't hold out on us, share whoever.
There is some good experience on this forum, they'll let you know if it's up to snuff.
Quote from: SmokyOwl on August 09, 2022, 09:16:13 PMAt first I was planning on just upgrading the connecting rods and keeping the same pistons as the compression is quite good right now- thinking why mess with a good thing right? But then it hit me, the moment the pistons are removed- the rings wear grooves are NEVER going to match up again.
Breaking news: Rings spin in the bore and on the piston.
Do a search on this forum even. Plenty of talk of it.
Don't change your gear ratio higher and expect better mileage because you'll be getting on it all of the time just to maintain speed. When I changed from the stock ratio of 3.15 to 3.37 I gained 4 mpg because I didn't have to keep giving it the gas.
cling
:agree: I get better mileage and power with a 3.15 ratio than the stock 2011 RGU. I run at * 3,000 rpm on the highway and really notice the difference.
Quote from: 02roadcling on August 10, 2022, 10:43:12 AMDon't change your gear ratio higher and expect better mileage because you'll be getting on it all of the time just to maintain speed. When I changed from the stock ratio of 3.15 to 3.37 I gained 4 mpg because I didn't have to keep giving it the gas.
cling
I noticed the same drop in mileage going to the higher ratio on my 2000 88 motor.
I solved THAT issue by going to 95", Andrews cam, re-jetted carb.
Now I get better mileage! LOL
JME
:potstir:
Quote from: HogMike on August 10, 2022, 12:14:26 PMQuote from: 02roadcling on August 10, 2022, 10:43:12 AMDon't change your gear ratio higher and expect better mileage because you'll be getting on it all of the time just to maintain speed. When I changed from the stock ratio of 3.15 to 3.37 I gained 4 mpg because I didn't have to keep giving it the gas.
cling
I noticed the same drop in mileage going to the higher ratio on my 2000 88 motor.
I solved THAT issue by going to 95", Andrews cam, re-jetted carb.
Now I get better mileage! LOL
JME
:potstir:
:agree: I went to 120" and got the same results. :wink:
Quote from: kd on August 10, 2022, 12:50:20 PMQuote from: HogMike on August 10, 2022, 12:14:26 PMI noticed the same drop in mileage going to the higher ratio on my 2000 88 motor.
I solved THAT issue by going to 95", Andrews cam, re-jetted carb.
Now I get better mileage! LOL
JME
:potstir:
:agree: I went to 120" and got the same results. :wink:
I went from 96", to 107", to 117", to 124", and each step used more fuel. I don't cruise much though. :chop:
Quote from: Ohio HD on August 10, 2022, 01:33:43 PMQuote from: kd on August 10, 2022, 12:50:20 PMQuote from: HogMike on August 10, 2022, 12:14:26 PMI noticed the same drop in mileage going to the higher ratio on my 2000 88 motor.
I solved THAT issue by going to 95", Andrews cam, re-jetted carb.
Now I get better mileage! LOL
JME
:potstir:
:agree: I went to 120" and got the same results. :wink:
I went from 96", to 107", to 117", to 124", and each step used more fuel. I don't cruise much though. :chop:
Us flat landers find the fuel usage increases with cubic inches. :wink:
Rings won't spin in 2 stroke engines (transfer ports), and if your CROSSHATCH is screwed up or worn out, they won't spin either.
John
Well I guess it's good to know that I have the option to keep my stock 88 pistons without worry. Depending on the bore wear I may go aftermarket if honing is necessary, but I kinda doubt if honing will be necessary with just passing 30k miles this week.
I had some fun messing around with primary and final ratios on gearingcommander. For fun I found if I tweak each pulley by fairly easy online options (changing from a 36/25 to a 35/26, and belt pullies from 32/70 to 34/65), I could cruise at 60mph in fifth gear at a little over 2k rpm and leave 6th gear for interstate use. I'd have a heck of a top speed lol, but then reality hit- it'd probably be a real chore walking away from a stop sign and any traffic jam would be a clutch nightmare.
Unfortunately I was looking at the 30mph speed area and it looks like it would just not work out doing anything less than the extreme option, because if I do the gearing options at anything less I'd be stuck in 2nd at annoyingly high rpms while tooling around town at 30mph. Oh well, another dead idea.
QuoteI could cruise at 60mph in fifth gear at a little over 2k rpm and leave 6th gear for interstate use. I'd have a heck of a top speed lol, but then reality hit- it'd probably be a real chore walking away from a stop sign and any traffic jam would be a clutch nightmare.
Everything about these statements makes me cringe. Imagine taking a pry bar and moving the pivot point toward you till the bar bends. That is sort of what you will do to your engine. Lugging it may tear up the bottom end in time, and in most cases will not increase your top speed because you will not have the power to overcome the wind resistance. You would be much better off cruising at 3000 RPM or above.
Quote from: smoserx1 on August 11, 2022, 04:00:15 AMQuoteI could cruise at 60mph in fifth gear at a little over 2k rpm and leave 6th gear for interstate use. I'd have a heck of a top speed lol, but then reality hit- it'd probably be a real chore walking away from a stop sign and any traffic jam would be a clutch nightmare.
Everything about these statements makes me cringe. Imagine taking a pry bar and moving the pivot point toward you till the bar bends. That is sort of what you will do to your engine. Lugging it may tear up the bottom end in time, and in most cases will not increase your top speed because you will not have the power to overcome the wind resistance. You would be much better off cruising at 3000 RPM or above.
Agreed. That 88" motor will struggle at 2000 rpm to keep your speed at 55mph, and you will find yourself twisting the throttle much more than if you were running closer to 2600-2900 rpm.
I run a 95" with a 5 speed, 3:37 gearing. I get better gas mileage and much better manners running 4th gear in most situations at 55 mph. I can go to 5th and run, but if I'm struggling to hold speed (windshield bucking wind, or some uphill grade, or two-up) I twist the throttle more, the motor struggles a bit, or rather isn't happy, and my gas mileage goes down noticeably.
I get this a lot when I mention my low rpms at cruising speeds. I'm not intending to pass anything or even accelerate, and I have enough power to overcome any hill I encounter. Realistically I was even checking out my rpms last night, and it's actually more around 2,100 to 2,200 in 6th at 60, and I concluded the slight increase in rpms vs what the data online says is due to my rear tire wear. Honestly I don't have any trouble at all until about 55mph, and that's more like 1,900 to 2,000 rpm- the bike doesn't like that and when that happens it's usually the result of fatigue or lack of attention. When I'm hitting 3,000 rpm doing 80 down the interstate, I get a significant drop in mpgs, like 4 or 5 mpg less from the increased rpms. I notice similar results when driving my car at higher speeds/higher rpms too.
The reason for the poor mileage has to do with pushing air at 80 mph. Run those rpm at 60 / 65 and you will be pleasantly surprised. The engine isn't suckholing to push that billboard through the air anymore.
I have a 2004 Fatboy that has had buzzy vibration since it was new, anything over 2750 rpm it would buzz and vibrate horribly higher rpm the worse it was
I ended up with a 95" HTCC cylinders pistons and heads with 57mm throttle body S&S 510 cams upgraded to a 2006 ecm wired in O2 sensors tuned with TTS using 86 octane fuel 180 ccp both cylinders at 6000'elevation and delivers 52-54 mpg consistently a good tune really helped with the buzz vibration above 3000 rpm not as severe as it was stock but it's still there anything above 75 mph checking the mirrors is just a suggestion
I have around 65K miles on it now someday I may have to address the buzz but until then I'll just ride it
Hi SmokyOwl,
Hang on a tic - you say " It definitely wasn't in the wheels, as the vibration immediately vanished upon pulling in the clutch."
If the vibrations cease when you pull in the clutch, it's not the balancers is it? I'd be starting at the clutch unless the vibration persists with the clutch disengaged.
Thanks
Pauly
Quote from: SmokyOwl on July 20, 2022, 01:34:23 PMSo my bike, a 2006 88" EFI Softail Fatboy, now at 29k miles, had vibration issues while on a long trip from Wisconsin. First a little history. The bike was running perfectly fine around my area until my local dealership in Madison installed an S&S hydraulic chain tensioner upgrade 10 months ago, when I IMMEDIATELY noticed a bit of vibration that wasn't there before (like, out of the parking lot noticed it). Not terrible, just made my hands numb after 20 miles or so, it just felt different and I knew with no cam or other changes the bike SHOULD run the same. However they couldn't find anything, and ended up tuning the vibration out, which smoothed things out until about 65mph and above, which made it tolerable in my area. However after thinking about it, I doubt they spent 10 hours taking everything apart a 2nd time to actually check their work. That's a lot of company time.
So onto my story. From Wisconsin I made it to Kansas when I started noticing vibration, and after hitting Amarillo TX and west to Albuquerque NM the vibration was getting worse to the point I aborted my run. I was stopping every 30 miles or so to let the bike cool because at the time I thought it was heat related as it was 100 degrees in the area at the time. After many miles of experimentation I found it wasn't the speed I was being forced to run (typically 85mph posted EVERYWHERE) as it was the rpms. Usually around 2800-3000 rpms is when the vibration was getting pretty intense, feeling it most in the foot pegs and seat, less in the handlebars. The vibration when starting the day cold would be fairly minimal up until about 5 to 7 miles (when the engine got up to temperature, which is why I thought it was temperature related). However, in Wisconsin the elevation is about 1,000 feet....and in Texas and New Mexico it was about 5,000 to 7,000 feet. Now I want to imagine the EFI injection SHOULD compensate for this. It definitely wasn't in the wheels, as the vibration immediately vanished upon pulling in the clutch. Seems everybody's first thought was an unbalanced wheel everywhere I went.
Dealership in Amarillo TX found a loose top mount bolt loose, but that ended up changing nothing and onward west I went into Albuquerque dealership, who gave me a couple possibilities- both rather expensive, their first thought was the internal balancers, or the compensator. I have since scratched off both these as possibilities as I have no rattling in the primary for a compensator, and I'm told the internal balancers would make the bike vibrate ALL the time, immediately upon starting and all. Not to mention that it would be unaffected by elevation.
So onto my elevation subject. Upon abandoning my run west I headed straight north into Colorado, which was a great reprieve of the 85mph speed limits and let me take it easier at the slower mountain road speeds. Despite the elevation of 10,000 feet the bike was performing well at lower rpms and speeds of under 60mph. The local dealership, Avalanche, was absolutely fantastic btw as they were the first dealership to really listen to what I was saying, but again came up empty on a solution other that for me to trade in my bike :hyst: . I entered South Dakota and started making my way east on the interstate at 80mph, at the time trying to make miles for the day. However at 80mph, the vibration was almost tolerable. Not the having to stop every 30 miles it was in the south. And as I went further and further east through Minnesota the vibration lessened, effectively back to normal as it was back home.....and that's when I noted the elevation of 1700 feet and dropping.
So when I got into Wisconsin again after over 4,000 miles, I pulled the plugs I had just installed before my trip began and I found the rear spark plug was white, and the front was a tannish brown. So the rear is running lean. Now being at high elevation I would think both would be running a bit funky with the thin air, but having one plug vastly different from the other is a big red flag that something is wrong.
I get back home and immediately ride to the dealership that caused the vibration issues in Madison, and the service supervisor is yet again scratching his head. He's thinking it's the compensator and not the internal balancer (thank god it's not the internal balancer) however with only 30k miles he still has his doubts it's the compensator...and I haven't had any compensator rattling issues. I am convinced it's something they messed up when putting in the S&S cam tensioner setup, maybe they didn't line up the rear cam correctly? If I can get them to open it up and check their work without costing me anything that would be nice. I'm thinking of ways for them to do it, I'm considering ordering them to check the crankshaft runout to force them to open it up again. I'd like to know what it is anyways, I forgot to have them check that the first time. Or I may have it dyno tuned somewhere, maybe I'll find answers there?
So full details of my bike, for reference:
88ci engine
6 speed screamin' eagle transmission
Master Tune II tune
S&S intake
V&H ProPipe
203 Screamin Eagle camshafts
When I pull in the clutch the rpms drop and are no longer near 3k rpm, I've tried pulling in the clutch then throttling the engine back up to 3k, it's still vibrates be because there's no load on the transmission not nearly as much. I've beaten that dead horse enough, it's not in the wheels.
So replacing the compensator didn't do anything, rode pretty much the same as it did before. The old compensator gear had very little wear with no running issues that I could tell. It had a LONG way to go yet before there was any issues. I'd say two of the three had minor wear to it on half of the groove, the other had negligible wear as you could still see much of the original casting. So....definitely not the compensator as the mechanic suggested. In the plus column tho it did give me an excuse to install a chrome inner primary cover, so it wasn't all for nothing and it has eliminated the compensator as a culprit.
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cam off a tooth or torn oil pump oring slight sumping at times ?