I was searching around for info on engine mounts and vibrations for my 89,,came across this from 2010 >"The pre-91 generations don't have rubber mounted engines like the later ones do. Never hurts to take something apart to clean and fix it, but you're not going to see huge gains in vibration reduction on the older machines" Are they not serviceable ?
I think the point of the comment was the joint is static. Why service it when its not broken. The joint will still be static after service and not likely to improve the vibration issue.
So, I have to disagree with Mark on the mounts. The left upper aluminum motor mount bushing is supposed to slide freely in the engine case lug. After years of road grime and water they seize in the bore. There have been many a puller made out of all thread, washers and a piece of pipe to press the bushing out of the case.
I read many posts from overseas where guys have drilled them out, ground them out, etc. because they couldn't press it out.
I only have one recommendation, do not....I repeat...DO NOT try and get it out with a hammer.
I broke the case on my 86' that way.
If you get it out, you can either polish the bushing and bore smooth, and reinstall with a high temp, synthetic grease.
Or you can eliminate the sole aluminum motor mount and install a new rubber bushing into that hole too: https://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3AEngDamper3 (https://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3AEngDamper3)
Randy - RPM
Quote from: racerrad8 on October 14, 2023, 04:48:43 PM
So, I have to disagree with Mark on the mounts. The left upper aluminum motor mount bushing is supposed to slide freely in the engine case lug. After years of road grime and water they seize in the bore. There have been many a puller made out of all thread, washers and a piece of pipe to press the bushing out of the case.
I read many posts from overseas where guys have drilled them out, ground them out, etc. because they couldn't press it out.
I only have one recommendation, do not....I repeat...DO NOT try and get it out with a hammer.
I broke the case on my 86' that way.
If you get it out, you can either polish the bushing and bore smooth, and reinstall with a high temp, synthetic grease.
Or you can eliminate the sole aluminum motor mount and install a new rubber bushing into that hole too: https://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3AEngDamper3 (https://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3AEngDamper3)
Randy - RPM
I'm experimenting fitting the 91 mounts on my 3CV 89, I have been avoiding any modifications to the main frame so if things become pear shaped I can easily return to standard. The solid rear upper mounts were removed and the two old rubber mounts from the lower front (with minor trimming) were fitted. With some luck I will be finished in a week or two, I'll keep you posted.
I have to admit if you don't have good hand, welding skills and a friend with a good lath, I would not attempt it.
If vibration is a problem, look elsewhere in the first instance with the 84-90 FJ's - start with carb balancing etc before you go tearing into seized engine mounts.
Even with seized mounts, the vibration levels on those FJ's isn't normally a bother on a nicely set up bike.
Quote from: Millietant on November 12, 2023, 09:29:50 AM
If vibration is a problem, look elsewhere in the first instance with the 84-90 FJ's - start with carb balancing etc before you go tearing into seized engine mounts.
Even with seized mounts, the vibration levels on those FJ's isn't normally a bother on a nicely set up bike.
I have to agree.
That being said, mine is needing attention.
I've never lubed the rear suspension linkage.
Quote from: Millietant on November 12, 2023, 09:29:50 AM
If vibration is a problem, look elsewhere in the first instance with the 84-90 FJ's - start with carb balancing etc before you go tearing into seized engine mounts.
Even with seized mounts, the vibration levels on those FJ's isn't normally a bother on a nicely set up bike.
Did that plus more like new chain/ sprockets, checked current engine mounts but the engine does have a few mods. Maybe not as bad as it sounds but my age does not like the extra vibs
Looks like it's time for thicker gloves and rubber soled boots then :sarcastic:
Quote from: Millietant on November 13, 2023, 05:21:11 AMLooks like it's time for thicker gloves and rubber soled boots then
Turbocamino,
Padded gloves and padded foot rests are certainly a valid set of options.
I would add, converting to standard (7/8" 22mm) handlebars will also help a lot.
The EM standard handlebars are too rigid, and they transmit the vibrations into your arms.
These mods will benefit you far more in reduced vibrations than the motor mounts.
My US$ .02 worth . . .
I found these help to reduce the high frequency vibes...
(http://www.rpmracingca.com/prodimages/large/M%20C%20RPMbarend-1.jpg)
http://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3ARPMbarend (http://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3ARPMbarend)
Well its done, no frames were harmed during this photo session. Considering my modified engine vibrated a bit more than the standard, now 90kph and above is very smooth to a point where I hardly use my cruise control.
Not only were the front mounts done but the rear/top solid mounts were replaced with a set of slightly shaved down standard engine mounts.
I did have a scare on the weekend where the engine felt like it skipped a cog but the culprit turned out to be a loose chain (I had a brain freeze when adjusting).
NOTE: I would not do this mod on my Standard FJ, again if your skill sets are limited DO NOT ATTEMPT THIS.
I do have an option of returning to standard as no main frame modifications were done.
John,
I am not sure what you did here.
Did you add the 91+ frame rails to your 89-90?
Randy - RPM
Quote from: racerrad8 on December 10, 2023, 02:24:44 PM
John,
I am not sure what you did here.
Did you add the 91+ frame rails to your 89-90?
Randy - RPM
I used the bottom rails/ mounts off the 91 ( cheap second hand), modified to bolt onto existing 89 main frame, great results very smooth from 90 up I just did a 1000km (for a charity run) return run wearing MX gloves (warm weather) I had no tingles. Below 90kph the vibs are down (to previous) but noticeable.
The engine brass bushes also had to be made using relay arm collars (machined length to suit- I have a friend with a good lathe)
Excellent, going to need some more details on the conversion.
Did you use a bushing within the brass sleeve?
Also, the modifications to the actual frame rails. Did the rear section bolt right up?
Nice work.
Randy - RPM
Quote from: racerrad8 on December 10, 2023, 07:37:02 PM
Excellent, going to need some more details on the conversion.
Did you use a bushing within the brass sleeve?
Also, the modifications to the actual frame rails. Did the rear section bolt right up?
Nice work.
Randy - RPM
Thankyou Randy, even though the vibration wasn't much harsher than a standard 3CV (my second FJ) I found the modified engine annoying. Therefore this modification.
- the rear bolts straight on, Yamaha is not perfect so some routing of holes (1mm Max) was require
- cutting and sizing the bottom frames was not easy as where they bolt together to the main frame is actually part of the cast junction which is very strong
- Meanwhile my friend machined brass bushes to real arm collars (of an FJ swingarm) cut to fit, seals are standard off the shelf
- the two rubber mounts (3CV) that are no longer used were used at the top rear of the motor to replace the solid mounts
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