How bad is it?

[mickarch]

Hello Everyone,
I'm pretty sure I've done something bad to my '93, I'm just wondering how bad...  This past summer I rode from Detroit down to the Smokies via Skyline Dr and the BRP (had to endure some horrible slab though Ohio to get there, but it was worth it ).  I had just swapped the rear wheel to 17" and installed a 18T front sprocket which of course lowered my rpm's.  Also, 99% of my riding being done on flat, straight roads, I was quite the noob in the mountains.

Anyways, I was taking a side trip of the parkway and found myself on some great twisties the likes of which I'd never experienced.  Being inexperienced at tight corners with treacherous drop-offs, I screwed up judging a corner and went in too hot.  It was a right hander that had a downhill entry and steep uphill exit.  I was going too fast for my abilities and realized it just before the turn-in, got on the brakes and made the turn just fine, but due to the steep exit and hard braking bled off almost all my speed by the exit.  I rolled the throttle on only to feel a violent shudder and a horrible sound from the exhaust.  Immediately realized I didn't downshift from third.  I was rolling on to full throttle in third going may 10-15 mph uphill

Ever since that mistake, the engine makes a distinct knocking sound at start-up for about a minute and then it subsides at idle.  I get the same knocking sound starting from a stop unless I rev the hell out of it.  Based on what I've been reading, my guess is I damaged either a conrod or crank bearing. I'm surmising that once the oil pressure is high enough, it stops knocking. What I'm really wondering is just how durable is this engine?  I've put about 2,500 miles in since the incident and the sound hasn't worsened.  I tend to take long trips though, so dependability is important to me.  I'd like to address this over the winter if I can find the time.

Is there a quick way to diagnose where the problem is without a full tear down?  The motor has about 40k miles on it and if I do have to tear it down all the way, is a full rebuild advisable (it was running perfect before I f'd it up)? 

Thanks for reading, I appreciate any and all advice 
Mickey

[FJ111200]

I'd start with the easiest part to get at first, the clutch.
Then if that checks out fine when re-assembled and you've still got the problem, either live with it or go for the tear down.

[racerrad8]

I doubt it is a bearing rod or main bearing issue. That noise will not go away and will continue to get worse. Like already mentioned I would lean towards the clutch to start your inspection. The fiber plates are made from aluminum and can crack.

If you cracked a disc, then when it is cold it could be banging around making noise, then when it warms and expands the noise subsides.

Have you try to pull in the clutch at idle to see if the noise goes away? When the trans is in neutral the gears are spinning and can be banging on the cogs as well.

Depending on how long you have run the oil, it might worth an oil change as well to see if that might have some resolve as well.

Randy - RPM

[Mark Olson]

I f the noise goes away when it warms up , don't sweat it .

if it gets louder then you got a problem .

I have all kinds of rattles and knocks when cold and still quiet down when warm.

I abuse the hell out of the engine and it likes it.  when I finally blow it up I am going big bore monster.

[mickarch]

Thanks for pointing towards the clutch, I hadn't considered it since it hasn't been acting up. I'll definitely start there. I changed the oil as soon as I got back from that trip.  I'm familiar with most of the strange noises, this one just started at the exact same time as me lugging it pretty badly which got me concerned. If I can get in the garage tomorrow, I'll take apart the clutch and see if anything looks off.
Thanks again,
Mickey

[mickarch]

I got into the clutch today, no cracked or broken friction plates.  Everything was quite clean.  There are a few things that I'm wondering if I should be concerned about:

The ears on some (but not all) of the friction plates are showing some wear which I believe to normal, but how much is too much?



The last steel in the stack towards the engine is scored, should it be replaced?



There was what seemed to be a fair amount of play in the outer clutch basket.  I took a short video of it, if you turn up the sound you can hear the clunking it makes as I'm moving back and forth (maybe 1/32" or so movement). Is this normal, or should I dig further?



Also, does the fine wire that held the last steel and friction plate in need to be reinstalled?

Thanks,
mickey

[Pat Conlon]

....Also, does the fine wire that held the last steel and friction plate in need to be reinstalled?

You're kidding, right?  http://www.fjowners.com/index.php?topic=1808.0

[mickarch]

Sorry Pat, hadn't looked in that thread because I wasn't having any clutch slipping problems. Got it though, throw the wire away. 
Thanks,
Mickey

[mickarch]

Can anyone comment on whether the play in the clutch basket is typical, or something I should be concerned about?  Since I've got it all apart anyways, I'm going to replace the fiber plates, install the full size one in place of the inner half size plate, replace the scored steel and throw in a new spring.  Will be putting in an order to RPM shortly.  Just not sure if I need to address the play in the clutch basket.

Thanks,
mickey