'05 with engine vibes

[Butta]

Ok, I've got about 55 hours on my '05 and the valves were in spec as of 8 hours ago (gonna re-check them this week when I replace the cam chain), but I've got a bit of a vibration, not a noise or banging, but a vibration directly related to rpm and indifferent to forward speed or clutch dis/engagement. I've checked the flywheel and woodruff key, and they looked like new. I've checked the clutch all the way to the clutch boss, and the primary drive gear and balancer drive gear. I'm planning on pulling the cams and changing the cam chain (and possibly tensioner) this week. I'm at a loss as to where this vibe is coming from. The best way I can explain it is that it feels like "something" is loose and transmitting a shaking motion thru the bike when you rev it. It runs strong, starts fine, etc etc....just shakes with excessive engine vibes. This started about 10 hours ago, but I wasn't sure of it until I rode a friend's 05 and knew right away I had excessive vibes. If the cam chain and tensioner aren't the blame, the only thing I can think of after that is the wrist pin bearing.......

any suggestions would be appreciated!!

Thanks!

[02YZ426]

This other 05 your rode, did it have rubber mounted handlebars on it? Maybe thats the only difference.. just the first thing that comes to mind. My 426 shakes like a jack hammer and Ive learned to deal with it. I will eventually change up my Vortex triple clamp for a rubber mounted Pro Taper when I get some extra cash.. that will help a bit.

[Butta]

It had different bars, but I've had this bike since new and it hasn't always been like this. When it was newer it ran as the other 05 did, nice and smooth (and tight).

[2fastwhitey]

Did you run the engine low on oil? That is usually the only way to destroy the wrist pin bushing.

[Butta]

Nope, never had it low on oil. Oil is changed every 5 hours, give or take one. Maybe I'm more worried about this than I should be??

[MotoGoalie]

Did you check all the engine mounting bolts? Including the head stay?

[grayracer513]

You mention clutch engagement. What does that have to do with it? Does the vibration come and go with the operation of the clutch? How? Does it follow the engine speed, or the speed of the bike? Does it do it only in (or worse in) one particular gear?

I'm thinking transmission and balancer issues, but I don't have enough to narrow it down.

[Butta]

You mention clutch engagement. What does that have to do with it? Does the vibration come and go with the operation of the clutch? How? Does it follow the engine speed, or the speed of the bike? Does it do it only in (or worse in) one particular gear?

I'm thinking transmission and balancer issues, but I don't have enough to narrow it down.

Sorry I wasn't more clear on that...the clutch has no effect on it, neither does what gear it's in or if it's got any forward speed whatsoever. It seems to me that it's motor only and is related to rpm (engine speed) only. I agree with you, Gray, about the balancer issue, but it checked out fine on the right side. I'll look closer into it hopefully tomorrow.

As for the motor mounts, that will also be checked tomorrow.

Thanks for the ideas....keep 'em coming if you can!!

[grayracer513]

There are 3 things that could be wrong with the balancer; a bad bearing on either side, or, if someone had it apart for some reason, it could be out of time. It has timing marks so it can be properly sync'ed counter to the engine vibration, but I'm guessing you knew that.

When you check the mounts, remember the swing arm bolt.

[Butta]

There are 3 things that could be wrong with the balancer; a bad bearing on either side, or, if someone had it apart for some reason, it could be out of time. It has timing marks so it can be properly sync'ed counter to the engine vibration, but I'm guessing you knew that.

When you check the mounts, remember the swing arm bolt.

I've owned it since day one, and it's never been apart. Is it possible to diagnose a bad bearing without pulling it all apart?

One thing that interests me is a little bit of wiggle to the cam chain. Behind the flywheel where it comes off the crankshaft you can push forward on it and it will move a slight bit. It takes a little pressure to get it to move, but I would have thought it to be a lot harder to move.....any suggestions?

[Butta]

Well, the engine mount bolts are all torqued to spec, including the swingarm bolt. I'm about to change the cam chain....the valves are in spec as well....perplexing....

I'm not sure how to check the balancer bearings, but I may have to find out...

?

[grayracer513]

Is it possible to diagnose a bad bearing without pulling it all apart?

There's a bearing on each side that you can see through either crankcase cover. The one under the ignition cover is a cartridge roller, or needle bearing that runs directly on the shaft, and is the more likely of the two to be bad. The shaft may be worn into as well. Check it by looking for up/down fore/aft clearance in excess of what seems reasonable. If you pull the right side open, you can check the ball over there, and even remove the gear and spin or remove the shaft. New bearings can be installed with the engine in the frame.

Remember, this is just a possible cause. Good luck with it.

[Butta]

I replaced the cam chain (probably unnecessarily, 'cause it was the exact same length as the new one, but it's good insurance). Now I'm thinking of replacing the woodruff key (it doesn't show any signs of rubbing on the flywheel, but it's rounded at the edges, not squared). As for the balancer bearings, I think I'll check them out like Gray suggested and see. I may even pull the right side off again and completely pull the balancer so I can check it out to eliminate things, if nothing else.

I'll keep updating......any other suggestions, keep 'em coming!

[MotoGoalie]

It's a good mystery. Hope you get it figured out.

[yz007f]

I ran into a problem with my 03 450, there is a nut on the end of the crank that holds a gear on that runs the water pump and balancer shaft. There is a lock washer on it mine looks like it never had the lock washer on it so the gear backed off and went into the case. I would check that nut out just to make sure. I was lucky and Yamaha Canada paid for my case. Also keep an eye on those pistons I have seen the piston skirts cracking. I know it has nothing to do with the viberation that you have but while your in the motor change that piston!

yz007f

[Butta]

Yeah, I inspected the primary drive gear and found nothing wrong....it is a mystery...one I hope to solve, 'cause I just can't see "living with it"....I'm afraid to run it until I figure this out (or at least eliminate every known cause) for fear of blowing it up.

[Butta]

Well, just got done putting it all back together with the new cam chain installed and cams adjusted, along with everything inspected. Started her up on the third kick and she runs like a dream. I'm very very relieved. The only thing I can think of is possibly the cam chain was having a rough spot in it as is moved over the gears or the cam chain tensioner might have been a little hesitant to extend as it should - when I put the tensioner in I used the screwdriver to ensure it was extended as much as it could (it was).

Anyway, thanks, as always, to those who offered suggestions. It's always a relief when it starts after putting it back together......let alone runs better!!

??