Vibration

[rasdes]

I have a vibration in the seat, tank and fender....anywhere you lightly placed your finger tips you can fell a strong tingling vibration, the pulsation is that of a hand massage vibrator. The pulsation increases with the engine RPM. All motor mount bolts are tight with red LOC-TITE. When sitting, raising the RPMs causes the rear fender to vibrate to the point it almost looks like a tuning fork. This may be normal, just not sure.....it may be a dumb idea but has anyone ever added rubber under the engine?

 

[IRONHEAD]

Your always gonna get some vibration with these bikes. A couple of weeks ago my 06 k9 was vibrating so hard at the right foot peg I couldnt keep my foot on it. Someone(Bubblehead) here suggested changing my spark plugs and the bike smoothed out so much I couldnt believe it. Maby you aught to try it.

 

[claw]

I had a very bad vibration for about the first 3 months I owned my bike. I also had checked the motor mounts as well. It wasn't till I went to change the coil that I discovered the problem. I removed the 3 bolts from the coil cover only to discover that the motor mount was loose, even though the bolt was torqued to spec. The long 1/2" bolt was bottomed out in the 'cone' on the other side of the frame before it actually tightened up. Put a 1/2" lockwasher in and problem solved.
Just because you put a wrench on it doesn't mean its tight. Just a thought.

 

[erldawg]

I have a vibration in the seat, tank and fender....anywhere you lightly placed your finger tips you can fell a strong tingling vibration, the pulsation is that of a hand massage vibrator. The pulsation increases with the engine RPM. All motor mount bolts are tight with red LOC-TITE. When sitting, raising the RPMs causes the rear fender to vibrate to the point it almost looks like a tuning fork. This may be normal, just not sure.....it may be a dumb idea but has anyone ever added rubber under the engine?

Did this just start happening?

 

[Scooter28]

i've had the same problem, but the first time the top motor mount bolt fell out, the next time it came loose even after loc-tite was put on it. Check the bolts again. also, if your fender is vibrating like a tuning fork, check those bolts again. I lost my bottom fender bolt as well, it is not easy to put in with the rear peg bar mount and the starter in the way. Good luck

 

[Nukeranger]

Just so you know, the women like that vibration. But of course, you want to get rid of the really bad vibs.

 

[BigDogBro1]

Sounds like more than normal vibration.

Make sure the coil cover to head bolts are tight. There is a fiber washer between the head and cover that may need replacing or its gone. I have installed slightly longer bolts as well at those two spots. When you tighten down the upper motor mount system, tighten down the upper motor mount frame bolt and the head bolts alternating between them so it aligns the coil cover against all mounting surfaces.

 

[Nukeranger]

I don't use the fiber washers and don't have abnormal vibrations.

 

[V]

One item i noticed on mine at the coil cover was the 2 allen head bolts that went throught the coil cover into the head. first thing I had done was to get longer bolts. But after a while I noticed that when I looked at the bolt I coud see a slight movement. Turn out that the washers had formed into to the slots of the coil cover allowing for movement /vibration.

I got some stainless steel fender washers and ground them down to fit the elongated slot on the coil cover so there was no room for movement and installed a lock washer on top of that with the longer bolts and blue loctite.

No prob after that. Also torqued the top bolt to spec with Red locktite.

 

[HMAN]

Fiber washers are heat insulators for the coil cover. They were not meant to stop any vibrations. just my 2 cents.

 

[Nukeranger]

Fiber washers are heat insulators for the coil cover. They were not meant to stop any vibrations. just my 2 cents.

Yep, but I don't care how hot the coil cover gets! Also, the first two Big Dogs I ever road from a New Orleans dealer vibrated worse than my 1968 BSA. I tried to explain that after 40 years of advances, this was wrong but the salesman stuck to "This is normal". It wasn't a big surprise that they closed shop.

Well excessive vibration is not normal and my Dog doesn't vibrate anywhere close to a 1968 BSA which was put together by pissed of British workers with sledge hammers and there were no torque wrenches used or even around the production line. Just a little info.

 

[BigDogBro1]

Yes, the fiber washers are used for a thermal break to the coil cover. Found some suitable replacements at a local hardware store and re-installed them with the following upgrades.

I used some longer bolts and modified some thick stainless steel washers to fit in the elongated coil cover slots. They still had some room to slide in the slot but it kept the socket head cap bolt head from digging into the slot. It also provides a good full contact flat surface for the split lock washers to land on. Used BLUE Loctite on the upper 1/4" of threads that entered the head. No problems with loose upper coil/head mount bolts any longer.

I just don't understand why people don't use flat washers on slotted hole parts.

Both our bikes are quite smooth running 2000 to 3500 rpms and don't vibrate much at idle.