I just got done putting a 113 s&s motor in a 92 fxr. While in there I replaced the front motor mount with the gooden-tite mount. From 2500-3000 rpm this thing shakes pretty violently. Doesn't transfer to the bars very bad but really bad on the frame. It actually loosened my oil filter. At idle and above 3000 it's great but when it decels to 3000 especially its bad. I'm new to rubbermounts and have spent a lot of time searching this topic to see what I'm dealing with. Will this get better with time? Is it totally the mount I picked? Has anyone used this mount with similar problems. 2500-3000 is a hard rpm to avoid.
Check the stabilizer link from the frame to the top motor mount is in the right position. Also if the links are old, replace them.
Quote from: Deye76 on April 09, 2019, 05:52:18 AM
Check the stabilizer link from the frame to the top motor mount is in the right position. Also if the links are old, replace them.
Why would the links being old matter. Worn or compromised maybe but it's a 92, they are old for sure.
Did you try running it with mount loose before tightening?That main bolt on the motor mount should slide in and out with no bind.
What exhaust do you have on it? I have a more-or-less stock exhaust on my FXR and if it's not installed just so, it will cause crazy vibration.
Jeff
Quote from: JC 92FXRS on April 09, 2019, 10:11:54 AM
What exhaust do you have on it? I have a more-or-less stock exhaust on my FXR and if it's not installed just so, it will cause crazy vibration.
Jeff
Supertrapp. I actually just adjusted the mount on that some and it did take some of the vibes out. But not all. I wonder if the damper on the exhaust mount isn't worn out and causing some of this.
"Why would the links being old matter."
Save yourself a few bucks and run those 27 year old links. WTFDIK
Quote from: Deye76 on April 09, 2019, 04:36:35 PM
"Why would the links being old matter."
Save yourself a few bucks and run those 27 year old links. WTFDIK
I thought they were heim joints with lock nuts. Is there something I'm missing here. Go back and read my response without trying to think I was being a dick for no reason.
If it were mine I would replace the rear mounts because they do sag and higher rpm could be allowing frame contact.
Heim joints are more specific to the side to side, but being very loose/sloppy you will get vibs caused by the hammering. These engines will vibe in a y-plane(not just forward/backward).
But as anyone who has ridden a rigid mount engine with the top mount loose knows, you will lose fillings... which is all frame fore-aft vibe.
Exhaust mounts are your next source on a rubber mount. Restraining and forcing the movement outside of the sweet spot, or hard part to hard part contact
Has/had the engine ever been dyno tuned?
Those were generally smooth engines, when in a good state of tune.
V-Thunder offers "shock absorber" style stabilizers.
" I thought they were heim joints with lock nuts. "
Whatever you want to call them. You asked. I replied. And yeah your reply came off as being a SA. I see your 35 yrs old, I knew everything when I was your age too.
Edit: Was only trying to help.
If you still have the original front mount i would try that. I have never had good luck with a urethane type mount when it comes to vibration.
^^^^^^^ THIS ^^^^^^^^
Also, I believe the FXR cleave blocks have a habit of binding up with age. Might want to get out the hammer and drift and "tap" those out & replace. While you're in there.
-JW
Quote from: Hillside Motorcycle on April 10, 2019, 04:01:33 AM
Has/had the engine ever been dyno tuned?
Those were generally smooth engines, when in a good state of tune.
V-Thunder offers "shock absorber" style stabilizers.
Have you ever tried the v-thunder stabilizers?
No it's never been dynoed. It's a new to me used motor and it came with a jetted super g carb. It seems to be jetted way lean based on S&s reccomendations. But seemed to run fine other than that rpm range which is also kind of the crossover from int to main.
In other words I'm dialing it in currently. First evo and first rubbermount so there's a learning curve.
You can check the heim joints for excessive play as you would check the front end ball joints on your car. It shouldn't be any.
Quote from: xlfan on April 12, 2019, 05:17:48 AM
You can check the heim joints for excessive play as you would check the front end ball joints on your car. It shouldn't be any.
There is none. That's why I questioned replacing them based on age alone. Often aged Harley parts are still better than aftermarket unless they are quality made.
How did you come across this engine? For that matter, do you know the honest history of it?
Considering the history of S&S engines being pretty reliable and balanced I'm skeptical everything is sound inside the engine.
Quote from: Mattbastard on April 12, 2019, 12:30:09 PM
How did you come across this engine? For that matter, do you know the honest history of it?
Considering the history of S&S engines being pretty reliable and balanced I'm skeptical everything is sound inside the engine.
me too
Quote from: Mattbastard on April 12, 2019, 12:30:09 PM
How did you come across this engine? For that matter, do you know the honest history of it?
Considering the history of S&S engines being pretty reliable and balanced I'm skeptical everything is sound inside the engine.
I get what you guys are saying but it runs great in every other rpm. I've currently been playing with the exhaust mounts a bit.
Quote from: motorhead_smf on April 12, 2019, 05:23:48 AM
Quote from: xlfan on April 12, 2019, 05:17:48 AM
You can check the heim joints for excessive play as you would check the front end ball joints on your car. It shouldn't be any.
There is none. That's why I questioned replacing them based on age alone. Often aged Harley parts are still better than aftermarket unless they are quality made.
"a spherical ball joint is designed to pivot through multiple planes. Since the ball joint constantly pivots at different angles,
it tends to wear more rapidly than bushings." Also stud corrosion can be a issue. "Technicians often have a problem locating valid specifications for ball joint testing."
When I put a S&S crate motor in a bagger 19 years ago, it had some vibration, changed the stabilizer links, smoothed out. Recently put a 113" motor in my 92' FXRP, tried it with the old links, had a vibration that shook everything at certain RPM's, replaced links, it helped a lot, didn't eliminate completely but helped. The cleve blocks in the swing arm I'm sure are worn as I have developed a wobble in the sweepers, that's next and may help some of the vibes. YMMV.
Quote from: Deye76 on April 13, 2019, 07:58:03 AM
Quote from: motorhead_smf on April 12, 2019, 05:23:48 AM
Quote from: xlfan on April 12, 2019, 05:17:48 AM
You can check the heim joints for excessive play as you would check the front end ball joints on your car. It shouldn't be any.
There is none. That's why I questioned replacing them based on age alone. Often aged Harley parts are still better than aftermarket unless they are quality made.
"a spherical ball joint is designed to pivot through multiple planes. Since the ball joint constantly pivots at different angles, it tends to wear more rapidly than bushings." Also stud corrosion can be a issue. "Technicians often have a problem locating valid specifications for ball joint testing."
When I put a S&S crate motor in a bagger 19 years ago, it had some vibration, changed the stabilizer links, smoothed out. Recently put a 113" motor in my 92' FXRP, tried it with the old links, had a vibration that shook everything at certain RPM's, replaced links, it helped a lot, didn't eliminate completely but helped. The cleve blocks in the swing arm I'm sure are worn as I have developed a wobble in the sweepers, that's next and may help some of the vibes. YMMV.
Good info. What parts are you using for replacements. I'm willing to try it for sure. My handling is plenty good and the donuts look to be in good shape. Also the swing arm seemed fine when I had the wheel off. I had most of the bike apart. This rpm is the only issue Ive developed/had.
I used Landmark, every now and then they are priced decent on Ebay. I have seen them price ridiculously high also. Not sure what the HD dealers are charging. Probably the ones Drag Specialties offers are OK. It's always a crap shoot throwing parts at a problem, but the inexpensive stuff rules things out before going inside the motor. A mal adjusted or worn primary chain is another culprit. Double check the placement of the link from the frame to the top of the motor mount. I mistakenly installed one to the bottom of the mount on a FXR I had in the early 90's, at 2600 rpm would loosen the fillings in my teeth. I got a service manual after that. :embarrassed:
Quote from: Mattbastard on April 12, 2019, 12:30:09 PM
How did you come across this engine? For that matter, do you know the honest history of it?
Considering the history of S&S engines being pretty reliable and balanced I'm skeptical everything is sound inside the engine.
The guy I purchased it from was very straight forward and has been nothing but helpful with any questions I had after the purchase. The more I have dug into this I think it's a problem with the tune of the carb in the midrange. I decided to change to a different pipe (rb racing) and will tune the carb from there and see if that doesn't help. It seemed like an overly rich condition which from what I've read is possible with similar configurations to what I have.