Plug color

[Tapartacus]

Thanks Kurt, used an impact drill/driver. Looks like the bolts had been fastened with heavy duty thread locker. They came out fine with driver. After removing two of the three bolts realized why all three have to come out. The lower bolt holds the tie that holds the engine mount collar bushing on the inside of the collar. Now its just a matter of removing the engine mount collar, cleaning and lubing and reinstalling. Will report back.
Andrew

[Tapartacus]

Well just got back from a long ride after removing, cleaning and re-greasing the engine mounts on my 92 and all I can say is... HOLY F$#%&*ING SH&%#@T!!!!! What a difference!! I can't believe it. I couldn't stop giggling like a little school girl every time I twisted the throttle. NO vibration in my hands which used to tingle after a hour of riding. Smooth as silk. At 60 mph and 4000 rpm it doesn't even feel like the engine is on. My problem with rumble at 1500 is almost undetectable. I will say that the most noticeable difference is at the higher rpm range but what a difference. I used to want to shift up to get rid of the vibration but now the more throttle I give it in any particular gear the smother she rolls. Anyone with a 91-93 who hasn't done this yet needs to do this NOW! Big thank you to all who suggested this and a big thank you to Bob from Ontario(good Canadian kid) for his guide and of course Pat, Randy, Kurt, DavidR, Noel. I'm just so giddy.
Andrew

[ribbert]

Well just got back from a long ride after removing, cleaning and re-greasing the engine mounts on my 92 and all I can say is... HOLY F$#%&*ING SH&%#@T!!!!! What a difference!! I can't believe it. I couldn't stop giggling like a little school girl every time I twisted the throttle. NO vibration in my hands which used to tingle after a hour of riding. Smooth as silk. At 60 mph and 4000 rpm it doesn't even feel like the engine is on. My problem with rumble at 1500 is almost undetectable. I will say that the most noticeable difference is at the higher rpm range but what a difference. I used to want to shift up to get rid of the vibration but now the more throttle I give it in any particular gear the smother she rolls. Anyone with a 91-93 who hasn't done this yet needs to do this NOW! Big thank you to all who suggested this and a big thank you to Bob from Ontario(good Canadian kid) for his guide and of course Pat, Randy, Kurt, DavidR, Noel. I'm just so giddy.
Andrew

Andrew, I love this post. I have tried a number of times to get this message across to anyone that owns one of these models but I've clearly been too conservative with my language.  Your description is excellent and to anyone reading this who hasn't done the mod, he's not exaggerating.

The word you used,  HOLY F$#%&*ING SH&%#@T!!!!! describes the feeling  perfectly. I wish I'd thought of it at the time. Perhaps it could join "kookaloo" in a list of FJ specific words.

I've said it before, this mod didn't improve the bike, it transformed it.

All Hail DavidR

Noel

[yamaha fj rider]

If you own a 91-93 FJ this should be done once a year or follow Noel's way with the grease fittings. Bottom line it's not that hard and makes such a big improvement, like night and day. Noel next time I take mine apart grease fittings are going in. Thank's for showing the way.

Kurt 

[ribbert]

Quote from: Tapartacus on September 01, 2012, 06:44:18 PM


"problem with rumble at 1500 is almost undetectable"

Both my bikes do the same thing.  My view has always been that it's just a critical rpm range at which everything chatters. It would be interesting to see if other bikes do the same thing.

DISCLAIMER: I do not ride in this rev range but occasionally find the engine under load, briefly, at those rpm and have noticed this.

The cause is only of academic interest because nobody rides at 1500 rpm, do they?

Noel

[Tapartacus]

Well I have mentioned it before in another thread... about the 1500 rpm vibration and I mentioned that it does not do it on my 89, the 89 purrs like a kitten. I will say that my 89 doesn't have near the power the 92 has(not to sure why that is) so I guess there is a give and take. Someone must have tinkered with the engine in the 92 before I got it, better rings, bigger pistons space shuttle cams, not really sure because the compression is quite remarkable. Let go of the throttle at 100 kms and hour and the bike almost wants to stop, strange indeed. Maybe someone wants to enlighten my dumb ass on these matters cuz I just don't get it.
Peace
Andrew

[ribbert]

Well I have mentioned it before in another thread... about the 1500 rpm vibration and I mentioned that it does not do it on my 89, the 89 purrs like a kitten. I will say that my 89 doesn't have near the power the 92 has(not to sure why that is) so I guess there is a give and take. Someone must have tinkered with the engine in the 92 before I got it, better rings, bigger pistons space shuttle cams, not really sure because the compression is quite remarkable. Let go of the throttle at 100 kms and hour and the bike almost wants to stop, strange indeed. Maybe someone wants to enlighten my dumb ass on these matters cuz I just don't get it.
Peace
Andrew

While riding today I intentionally induced the 1500 rpm shudder several times and still think it's just a critical rev range. The difference between your two bikes may be the engine mounts, solid v rubber.

As I said, both mine do exactly the same thing.

At the extreme end big marine engines have a critical rev range that if not passed through quickly can destroy the engine with vibration (resonance)

At the other end, I have a 1920's Austin 7 in my garage for an engine build. It's quite common to see these cars with a red arc on the tacho at the LOW end, somewhere around 1500 to 2000 rpm.  That's where they break crankshafts, frequently, and usually when not under load.

This IS only of academic interest because of the low speed and is only occasionally encounted when too lazy to change down a gear and wouldn't be surprised if most people reading this have fallen asleep by now as it's not a problem that needs solving nor impacts on normal riding.

Noel

[Tapartacus]

Well said Noel, with the new greased motor mounts I prefer riding above 3 grand anyway.
Andrew