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Gents, some of you will know I've been working on my 1992 Dyna FXDC since around February with various issues. I'ver got her pretty sorted on the cam chest / pushrods etc issues, toke the back head off to fish out a bloody screw driver that had fallen in, idiot! (at which point removed the top motor mount) and then she was running great except a loud clunking sound appeared after a few miles of riding. Did a quick review over the bike for anything loose and I'm pretty sure it was the front motor mount - I put her back tire up to check the side stand and this recreated the noise when idling. 2 weeks later got my front motor mount and yesterday put it on.
She rides fine now, the main clunking has gone but I still get the feeling she's not 100%, I don't so much hear anything but I'm feeling a slight knock 9perhaps its the back mount?). I haven't changed the back mount yet (I want to be sure its not an internal engine problem before I keep spending more money!). The question I have is that I had read up on shimming the motor mount to allow the rubber to work better but when i put the new one in place it seemed to be quite out of alignment...on one side. The bottom bolts I shimmed with 2 washers and that was fine as that's an up and down movement but the sides were very unequal.
I didn't know whether to simply tighten the bolt until is "squashed" the rubber together but i figured this would force quite a lot of lateral movement and strain on the mount/engine so i went with washers as you can see. She rides fine, and straight and the bolts went in with not stress.
Can someone please confirm if this is ok/normal or should i perhaps balance out the washers with 2 either side or just squash the top bolts together......OR does it mean my engine needs re-aligning? I think this is fairly simple without special tools ?
Both photos are taken when she's on her side mount by the way.
Thanks
I don't ride a Dyna so I don't have anything useful to add. That said, I'm do ride an older FXR ( 1985) and am always interested in topics relating to rubber mounts and alignment so I'll be sitting back, following the responses from people with pertinent DYNA knowledge and experience.
Looking at your pictures, I'm forced to question if using all those washers to shim things around isn't indicating that something is out of alignment elsewhere..??
I will go out on a limb and say those washers are NOT supposed to be there. Find a parts book, or at least an online schematic and start your research there. That looks very homemade.
Thanks Guido and Architect - absolutely correct the washers are not supposed to be there (no mention in the manual) and they weren't on the old mount one I took off, thats why I was so surprised to see such a gap in the top left when i fitted it. I'm just wondering if the motor mount comes quite wide and you simply have to compress it by tightening the bolts or perhaps I need to seriously realign the top mount?
Let see if someone can give me some direction. Thanks
I found this install video and took a screen grab of an "old" mount left, and a "new" mount right, and it does look like there is a big difference in the gap...which makes sense seeing as rubber will stay "expanded" if new and the old one will have lost some of its elasticity so will have compressed. Perhaps I have the engine a little out of alignment but should I just take the side washers out and tighten the mount up and then maybe review the top mount ? I don't know? Let's see if others chip in. Thanks.
You don't need the washers. The OEM mount is designed to be compressed when you tighten the 2 top bolts.
You don't need to align the engine. There's nothing in the Harley manual for aligning the engine. The function of the top mount link is to align the rear wheel. Notice in the Harley manual that it says after you adjust the top link (to align the rear wheel) you should loosen the motor mount bolts and run the engine so the mounts are in a relaxed position.
If you have a large gap between the front mount and the frame, it is because the rear mount is weak and the engine/tranny have shifted rearward.
Motor mounts work together as a system. If one is weak, the other one has to carry addition load and eventually weakens quicker. You should always change both front and rear mounts at the same time.
Looks like your engine moved to the left, because it was installed when the bike was on it's side stand. Do you have an FSM?
I'd remove the bolts when the bike is vertical. It may move back with a little help.
Have you ridden the bike like this? Does it "pull to the left?" Try it with no hands at 30-35 mph. (Don't be scared, you should have done this as a 9 year old on your Schwinn Stingray.)
Be sure the empty road is nice and FLAT. Get on the crown if you need to.
Thanks enginemounts, nice straight forward response. I was hoping that might be the reason, it certainly makes sense. I'll take the washers out and retighten and see how she runs and then yes, probably should do the rear mount also.
Thanks Nortyflatz, when i changed the mount she was vertical on a some blocks and then took the pressure of the engine with a car jack, I mention the photo was taken on the side stand simply so people would know its not visually straight - sorry for confusion. Yes she rides fine, only taken her out once and didnt let go but sounds like fun! I'll adjust as enginemounts suggests and then take her out again.
OK sorry to have wasted peoples time on this, I took the washers out and compressed the mount as suggested and it all looks fine and no big issues, photos attached also showing top and bottom gaps.
Unfortunately it has not fixed the loud "clunking" noise that i was getting while running, especially at around 2000rpm like something was loose and hitting the frame, for example the transmission clunking when i go over a bump. It might be the rear motor mount but either way Im pretty sure its an external action and hoping to hell that its not some internal part thats come loose at the big end.
I'll start another post for this once I've investigated some more.
Thanks. Compressed but still with bottom spacers, will recheck the rear mount before removing these To gap Bottom gap
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Front Isolator Mount
