Front Engine Damper

[Mike 86 in San Dimas]

Cut and paste, 84-90 Yamaha FJ Front Engine Damper, into the RPM web site or search https://www.rpmracingca.com/products.asp?cat=39&filter=84-90%20Yamaha%20FJ%20Front%20Engine%20Damper  you will see this little goody. Where does it go? Looking at some FJ parts drawings and paging through Clymer manual was not conclusive for me. What ever it is I bet mine is ready to be replaced. My guess is where the engine bolts up to the triangular bracket attached to frame. The next question; can an average Joe (that's my twin brother actually) with basic mechanical ability handle replacing this bad boy? I have installed much of the bolt on stuff from RPM s catalog  . But dont ask me use a set of calipers.

I am sensing the old girl is a little buzzier than she use to be. Could be like me she's just old. Monkey and I will do carb sync next week end. Maybe that will help some.
Thanks, Mike

[Pat Conlon]

It could be for 4 locations
2 (L/R) for the long bolt #10 and
2 (L/R) lower mounts where engine bolts #12 slips thru the cradle.

Others will chime in....

[4everFJ]

From memory, it looks like the damper used on the lower front engine mount.

It is easy to replace.

[Mike 86 in San Dimas]

thanks

[Firehawk068]

It is the right front lower engine mount "insert".
On my '90 the right side insert is this rubber one. The left side insert is solid aluminum.
I believe this is because the earlier bikes (pre '91) used the engine as a stressed part of the whole bike/frame/engine assembly.

You wouldnt have any trouble replacing it if needed.
I've had mine out before.

[Mike 86 in San Dimas]

It is the right front lower engine mount "insert".
On my '90 the right side insert is this rubber one. The left side insert is solid aluminum.
I believe this is because the earlier bikes (pre '91) used the engine as a stressed part of the whole bike/frame/engine assembly.

Cool. I always understood the engine being a stressed member(like me ) so I was curious about this part when I spotted it on the RPM site and wanted some clarification just where it is located. Not obvious to my naked eye.

[Mike 86 in San Dimas]

Retraction. I did not think this this engine was considered a stressed member. Engine considered stressed member;  wouldn't that be an engine that is actually part of the frame? Remove this engine and you still have great coaster.

[Pat Conlon]

Yea Mike, that what I was thinking also...

I recall reading that the aluminum bushing was used due to the twisting torque of the engine.

[Tor-King]

Retraction. I did not think this this engine was considered a stressed member. Engine considered stressed member;  wouldn't that be an engine that is actually part of the frame? Remove this engine and you still have great coaster.

Could this possibly be the reason why the perimeter frame on my '86 and '89 are substantially smaller in dimension than my '93?  I did notice that the mounting holes/brackets are very different on these engines as well.  It appears that the pre '91's use the engine as an important structural member...

Dean

[fnlyafjat51]

Look at items 40-43.
http://www.partzilla.com/parts/search/Yamaha/Motorcycle/1989/FJ1200WC/CRANKCASE/parts.html

How often do these tend to need replacing ? Does anyone make a Polyurethane replacement ?

[Mike 86 in San Dimas]

While looking for something else (in my files) I came across this. Not sure where I originally found it . Probably on a forum post. It is about replacing the "solid mount" with rubber. I might try it IF the solid piece comes out easily. Has anyone here tried this?  Hoping the attachment pops up when I click post. Here goes.

PS of course did not find what I was looking for 

[4everFJ]

While looking for something else (in my files) I came across this. Not sure where I originally found it . Probably on a forum post. It is about replacing the "solid mount" with rubber. I might try it IF the solid piece comes out easily. Has anyone here tried this?  Hoping the attachment pops up when I click post. Here goes.

PS of course did not find what I was looking for 

That is from the UK FJ club.

And yes, it does help with the vibrations, but it was a nightmare to get the sold mount out... 

[Tor-King]

Retraction. I did not think this this engine was considered a stressed member. Engine considered stressed member;  wouldn't that be an engine that is actually part of the frame? Remove this engine and you still have great coaster.

Could this possibly be the reason why the perimeter frame on my '86 and '89 are substantially smaller in dimension than my '93?  I did notice that the mounting holes/brackets are very different on these engines as well.  It appears that the pre '91's use the engine as an important structural member...

Dean

THANK YOU Mike for providing that link.  That answers my above question as to why the frames are larger and more stout on the last gen.

Quote from the article:
"The later models have the engine totally rubber
mounted in its three mounting points.
Because the engine is used to brace the frame the
later models have a thicker so stronger frame to
take care of this.
This mod on the early models doesn't have the
same problem as the motor is still strengthening the
frame due to the seven mounts as oppose to just
three."

[Mike 86 in San Dimas]

Yeah I was going to note something about that too. It sort of showed everyone's thoughts were correct at some level...I would not consider the 86 engine a stressed member in terms of it being a vital part of the frame though. Many, probably most sport bikes don't not have a "perimeter frame" like the FJ. In many the engine kind "hangs" from the upper frame, hence become the lower frame of the bike.   From my perspective the CBX is an example of a stressed frame bike. That about as far as this shade tree mechanic can take it