September 20, 2024, 03:19:00 PM

News:

For advertising inquiries or help with registration or other issues, you may contact us by email at help@harleytechtalk.com


MPG drop after replacing tensioners?

Started by Jeffd, August 26, 2011, 03:30:02 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Sc00ter

It's easy enough to check for sumping.  It's worth the few minutes to eliminate the possibility. 

Jaycee1964

If it is stock with just the 211's the 200lbs of compression that seems awful high :scratch:.  I'll bet it had a piston change and or decking of the heads.  I'de dig into it a bit more to be sure what you have.
If you have to stop and think about if it is right or wrong, Assume it is wrong.

Jeffd

Quote from: Jaycee1964 on August 27, 2011, 05:23:59 PM
If it is stock with just the 211's the 200lbs of compression that seems awful high :scratch:.  I'll bet it had a piston change and or decking of the heads.  I'de dig into it a bit more to be sure what you have.

I informed him of this site so hopefully he will check it out.

rigidthumper

IIRC, 200PSI was common with 211s on a 95" SE cast hi comp piston, .030 cometic HG, and 82cc chamber build. Sumping would have to be looked at. Overfilled primary can reduce milage a little bit. Time to look at the plugs and see what is happening in the chambers.
Ignorance is bliss, and accuracy expensive. How much of either can you afford?

rbabos

So, it runs strong, no pinging, no increased heat , no carry over to the breather. Just about rules out anything mechanical, doesn't it?
I vote botched mpg checks, or inconsistancies on how they were done. One tooth out on cam timing can have a major effect on the tuning and how it runs. I'm not reading any problems like that.
Ron

Jeffd

Quote from: rbabos on August 28, 2011, 06:48:28 AM
So, it runs strong, no pinging, no increased heat , no carry over to the breather. Just about rules out anything mechanical, doesn't it?
I vote botched mpg checks, or inconsistancies on how they were done. One tooth out on cam timing can have a major effect on the tuning and how it runs. I'm not reading any problems like that.
Ron

that was my thoughts on mechanical thinkgs.   His mileage dropped over 3000  miles ago and he has to fill up every day vs every other day before. He does over 100 miles a day round trip so not the math.

rbabos

Quote from: Jeffd on August 28, 2011, 08:47:14 AM
Quote from: rbabos on August 28, 2011, 06:48:28 AM
So, it runs strong, no pinging, no increased heat , no carry over to the breather. Just about rules out anything mechanical, doesn't it?
I vote botched mpg checks, or inconsistancies on how they were done. One tooth out on cam timing can have a major effect on the tuning and how it runs. I'm not reading any problems like that.
Ron

that was my thoughts on mechanical thinkgs.   His mileage dropped over 3000  miles ago and he has to fill up every day vs every other day before. He does over 100 miles a day round trip so not the math.
Interesting. This might not even be related to the tensioner change. Could be just that a sensor happen to crap out at the same time. I'd go with the head temp and iat based on the going rich. Codes are not always thrown on these as long as they function to some extent.
Ron

flash

 hello i just joined this forum after jeff told me about it.        it is my bike he posted about, so i will give more info.  i bought the bike used with 24,000 or so miles on it. i had put about 35,000 miles on it before the cam chain tensioners problem. so i know what kind of gas mileage the bike got in  normal riding conditions. one of the posts thinks i may not know how to check gas mileage, so here is how i do it. fill up and reset trip meter. ride till i need gas, fill up again divide miles traveled by gallons of gas used, and i use a calculator to do the math.  the first clue the mileage had dropped was the low fuel light coming on at 147 miles. it used to come on around 190 or so unless i was traveling above 90 mph for most of the tank.  more info on the bike setup 95ci kit se211 cams se air cleaner se slip on mufflers and was tuned with the race tuner but i did not get what i need with the bike to have it retuned.        to answer a few questions from the posts i did not remove the gas tank, it has adjustable pushrods so was no need to.  i have also considered this may be unrelated to the camplate upgrade.     i changed my oil a few days ago and i drained the case from the sump plug. i got 5.5 oz. of oil ot of the case. is that enough for this to point to wet sumping? i know the crankcase dose not have much oil in it but dont know how much should come ot when drained. before i changed the oil i rode 50 miles so it would be good and warm. i am going to change the fuel filter and see if that could be it. i hate to just throw parts at this thing but am not sure where to look next. thank you for all the replies and for any help.

Admiral Akbar

Quotei have also considered this may be unrelated to the camplate upgrade.

Thought you only replaced tensioners.. What else was replaced?

Max

flash

replaced the cam bearings in the case. lifters, and installed the se upgrade kit that is a new cam plate with hyd tensioners and the new oil pump that comes in the kit. secondary cam chain , new bearings in the camplate. primary cam chain and sprockets  which were part of the camplate upgrade kit were installed as well.   

Sc00ter

Quote from: flash on September 03, 2011, 08:35:34 AM
hello i just joined this forum after jeff told me about it.        it is my bike he posted about, so i will give more info.  i bought the bike used with 24,000 or so miles on it. i had put about 35,000 miles on it before the cam chain tensioners problem. so i know what kind of gas mileage the bike got in  normal riding conditions. one of the posts thinks i may not know how to check gas mileage, so here is how i do it. fill up and reset trip meter. ride till i need gas, fill up again divide miles traveled by gallons of gas used, and i use a calculator to do the math.  the first clue the mileage had dropped was the low fuel light coming on at 147 miles. it used to come on around 190 or so unless i was traveling above 90 mph for most of the tank.  more info on the bike setup 95ci kit se211 cams se air cleaner se slip on mufflers and was tuned with the race tuner but i did not get what i need with the bike to have it retuned.        to answer a few questions from the posts i did not remove the gas tank, it has adjustable pushrods so was no need to.  i have also considered this may be unrelated to the camplate upgrade.     i changed my oil a few days ago and i drained the case from the sump plug. i got 5.5 oz. of oil ot of the case. is that enough for this to point to wet sumping? i know the crankcase dose not have much oil in it but dont know how much should come ot when drained. before i changed the oil i rode 50 miles so it would be good and warm. i am going to change the fuel filter and see if that could be it. i hate to just throw parts at this thing but am not sure where to look next. thank you for all the replies and for any help.

2/3 oz. would be ideal, but 5.5 oz. in the crankcase is not excessive...

wholehog

Just for "Potty mouth"s and grins...what was the before and after gas mileage?

flash

Quote from: wholehog on September 03, 2011, 11:44:09 AM
Just for "Potty mouth"s and grins...what was the before and after gas mileage?
depending on how fast i rode 40-46 before and 31-36 after .  before i never got under 40 in 35,000 miles or so. after i have not got better than 36 in about 4,500 miles

pappy42

I hate a mystery!  Can't wait for the ending where the guru solves the problem.

wholehog

Quote from: flash on September 03, 2011, 08:35:34 AM

was tuned with the race tuner but i did not get what i need with the bike to have it retuned.   



even if you dont have the sert dongle, you can read the sensors with any one else's sert -- you just cant tune it.....

barny7655

When talking gas milage i would first go to the pump and check delivery pressure , id check air cleaner or infection, restrictions, 3rd check out the exaust system isnt blocked, and make sure the service centre you get fuel from hasnt changed supplier to a ethonol blend other than what you have been using , try a different pump gas ,make sure the bike when riding along will not pull up when in neutral  to brake drag , primary chain etc ,any air leaks aroung throttle body,sensors O rings okay , good luck , cheers Barny
riding since 62, BSA bantum the first bike

coastie56

My fuel mileage recently dropped and my stage 2 95 would cough under hard decel,occasionally if the tank was half filled. I have read many posts with same complaints that were eventually found to be a hole in fuel line in tank. Going on reserve too soon was also my first clue. It is easy to do a basic check. Take the fuel cap off, and while you have your ear to the filler turn on the ign switch. You will hear the fuel pump pressurize than stop. When it stops it should be dead silent as it is holding 55 lbs pressure. On mine, I could hear a faint pissing/splashing noise. The pinhole in the line was allmost too small too see with my 55 year old Mark 2 eyeballs. I caught it right when it started, within a couple weeks. I was in the local dealership buying the parts so I checked a couple of their used bikes on the floor. Their parts guys were stunned and irritated when I pointed out the same noise on two other bikes, probably traded in because they couldn't diagnose the trouble! I bet this is more common than people know and I found out that my line rubbed through where it was contacting the TOP of my gas tank because they were all built too long from the factory. The updated part is an inch or so shorter.

pappy42

Quote from: coastie56 on September 04, 2011, 10:18:49 AM
My fuel mileage recently dropped and my stage 2 95 would cough under hard decel,occasionally if the tank was half filled. I have read many posts with same complaints that were eventually found to be a hole in fuel line in tank. Going on reserve too soon was also my first clue. It is easy to do a basic check. Take the fuel cap off, and while you have your ear to the filler turn on the ign switch. You will hear the fuel pump pressurize than stop. When it stops it should be dead silent as it is holding 55 lbs pressure. On mine, I could hear a faint pissing/splashing noise. The pinhole in the line was allmost too small too see with my 55 year old Mark 2 eyeballs. I caught it right when it started, within a couple weeks. I was in the local dealership buying the parts so I checked a couple of their used bikes on the floor. Their parts guys were stunned and irritated when I pointed out the same noise on two other bikes, probably traded in because they couldn't diagnose the trouble! I bet this is more common than people know and I found out that my line rubbed through where it was contacting the TOP of my gas tank because they were all built too long from the factory. The updated part is an inch or so shorter.

OK, you baffled me here (not hard to do).  How did this leaking line lower your fuel mileage if it was leaking inside the tank?  I'm really not trying to be a smart alec; but I'm not following.

Admiral Akbar

I doubt leaking in the tank would do anything but let the motor run lean.Seems like that would increase gas mileage not cut mileage..   I'd look at the plugs. They should be nice and white. If not I'd look for leaking injector.. Going from 40-45 to 31-36 is a pretty radical drop. It might take putting the bike on the dyno to see if any issue can be diagnosed... Squeaking out  over 200 psi CCP could mean the outer chain is off 1 tooth but you it's not hard to get that much with higher compression pistons like Wisecos.  If the new outer chain and sprockets had some problem they could cause a change in performance but you would think that a new chain would advance the cams ever so slightly and not make much difference on the mileage..

Max

coastie56

A fuel pressure leak on the pressurized side of the oil pump lowered my mileage by 4 to 5 mpg, from41-42, to 36-37. It loses pressure to the injectors (the hoses are pressurized to 55 lbs per the manual) and causes the bike to stumble, and cough when the fuel level is lower than the pinhole, ie., when you brake hard and the gas flows to the front of the tank thereby sucking air intermittantly. Interestingly under most riding if the tank is full or nearly so, the bike seems to run fine. Yes i understand that it would seem that a lean condition would seem to cause it to get better gas mileage but in years of reading and tuning I have yet to see a twin cam run better in any way with a leaking fuel line. I have seen MANY people suddenly lose gas mileage and endlessly adjust power commanders and dfos and then discover that adjusting them richer was a band aid solution. If the cam was really off by a tooth it would run like crap. Anyway, it takes about 5 seconds to check and the cost is nothing. :nix:

Admiral Akbar

The above makes sense but it seems to me that the motor needs to be lean enough that it can't run efficiently.. In that case the motor runs like crap and the rider feels it.. Heck, a smogged bike can run bad and get a lousy mileage compared to a better tuned bike.

Is it the case above?  If the motor runs well, I'd say, "no"  Especially with a 200 ccp. There would be little balls of piston all over the plugs. Flip side with a high CCP, the motor could burn kerosene.. Too much fuel might appear as the slightest sogginess. No miss. Again you'll see it in the plugs.. I agree about cam timing.. One part of the power band will change with the cam off. Rider will feel it..

Max

wurk_truk

September 05, 2011, 05:19:13 PM #46 Last Edit: September 05, 2011, 05:21:49 PM by wurk_truk
Quote from: wholehog on September 03, 2011, 03:36:32 PM
Quote from: flash on September 03, 2011, 08:35:34 AM

was tuned with the race tuner but i did not get what i need with the bike to have it retuned.   



even if you dont have the sert dongle, you can read the sensors with any one else's sert -- you just cant tune it.....

Jeff's TTS Datamaster will work for this, too.
Oh No!

1FSTRK

"Never hang on to a mistake just because you spent time or money making it."

slypig

Slypig
Panama City Fl

1FSTRK

I was just wondering if they have made any progress on this. It is has been a real head scratcher and I am curious to see if it can be figured out.
"Never hang on to a mistake just because you spent time or money making it."