My buddy just picked up an f3 and it sounds worse than anything I ever heard. I don't have to put my ear up to it to tell it is coming from the cct area. I think the timing is out really bad from them ****ing with it. Any suggestions on if it even worth trying to fix or not. Will the motor ever run right again? It's worse at lower idle and never goes away. I rode the bike for a minute and it revved ok but sounded really really bad. I've never heard anything sound that bad and still run that good. HELP!!


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what type of noise is it? Clunking nosie, ticking noise, whurling noise....does it change at all when you do anything to the bike? Lean it over to one side compared to the other? Can you determine if it is coming from bottom end of bike or top end? The exhaust note, is it changed compared to your bike? If it has dropped a cylinder or two, it will be slow revving and sound like a tongue roll as you rev up instead of a vroom noise. Sorta hard to explain some of these noises. But more info is needed to help you out. Also...what where your friends doing to it? You talked about timing, if camshaft timing was played with and messed up, you could have damaged valves. But not able to determine that, unless you look at timing and do a leakdown test to see if any air pressure is leaking when the thing should be sealing.

 

It sounds like the cam chain rollin around in the top end on the right side. We didn't do anything to it yet. THe dudes we picked it up off of had the top off. Maybe a grindin noise or something but terribly loud.


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If the sound seems like it's coming from the top end, and they had the top end open, then that's the first place I'd look. Check to see that the cams are properly set when the "T" mark on the end of the crankshaft (right side inspection cover) is aligned with the index mark. Also, there shouldn't be any slack in the chain at all. If there is, then something is wrong with the tensioner.

This is the "T" mark.


Look at the sprocket for the intake and exhaust cams. They should both be aligned with the top of the cylinder head like so. If they're not, try turning the crankshaft 360 degrees clockwise and check again. You'll know if they're right. They either are or aren't.




Good luck.

 

thanks, I don't have the bike here or it would already be apart. I'll let guys know.


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If they were off 360 degrees the bike could have started but could not run. If it were off 360 degrees you couldn't rev your bike up as it would choke and die, like any car. (which works technically the same) So I'm guessing its not 360 degrees on or off. It could possibly be a tooth or two to the left or right. Timing is very critical. You definitely will not know anything without opening her up. So get ready for surgery. =P

-Jasper

 

I got the bike ripped apart and the tensioner was stuck. I had one from an f2 and it didn't bolt up but held it in with my finger and it stopped a lot of the noise. I'm gonna make a manual one next time i go over there by tapping the hole and putting in a carriage bolt upside down with a nut on the outside. The cams line up but what all effects can happen to the engine from being that bad. Should we replace the chain too? Can it put faster wear on the valves? What about the camshafts? Thanks for the responses.

 

Buy a new head if the bottom end is good. Problem solved

 

Maybe I'm wrong, but don't you mean 180 degrees off? If you turn yourself around 360 degrees from where you started. Your at the same location. Am I wrong with this thinking?

 

I want to fix this one. I'm halfway there just want to know what else to look out for. As it comes around to tdc the chain catches a little slack for a second but tightens back up. Is this normal? I haven't got over there to make my new manual tensioner yet. But while I got it opened up I wanna know what else to look for. Also, What kind of damage could result from the cam chain flopping around. The plunger was stuck on the one I pulled out. It was slapping all ove rthe place. The teeth on the cams didn't look terrible. What could this do to the vaves. Should I go ahead and get a shim kit?


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