Engine noise when cold, here are some findings...

[jplassy]

So here's the deal. I just bought a 00 Busa w/ under 1500 miles. The first day I start it up cold, rattly engine noise. I immediately think botched cam chain tensioner recall (the latest and greatest had been done by a dealer). I pull the valve cover and other bits (whoever did the recall managed to scrape airbox, valve cover, etc up, the stinking butchers). This is what I found. Loads of slack in the cam chain, way to go Suzuki on that cam chain tensioner design. I also checked cam timing, but here is the odd thing. The cams both seem to be retarded slightly, but not enough to be a tooth off. When I've seen this before in other bikes, with high miles, I've written it off to a worn cam chain. But why on my bike with only 1500 miles? Anybody else run into this?

So, for the time being, I clicked the tensioner in manually a notch, it took up some of the slack, I was too paranoid to click in again, don't want it overly tight, and restarted the bike. Less noise, but still noisy. Ape manual tensioner arrived Friday.

I'm going to look into the theory of the clutch bolts being loose (thanks gixxer man) to see if that has anything to do with it.

Any thoughts? Thanks in advance for your time.

 

[jplassy]

Well, I need to reply to my original post with a bit of an update. I checked the infamous loose clutch bolts to find they were all tight as hell. I was hoping to find them loose and to solve my noise problems. So any thoughts would be appreciated. Thanks in advance, Justin

 

[Curt]

i'm gettin some noises too, mostly at high rpm tho, doesn't matter cold or hot, i shud take a look at the tensioner, didn't know u could tighten it manually

 

[jplassy]

All the abnormally loose cam chains that I've heard (and have been able to follow up on w/ an actual inspection of the chain with valve cover off), have been noisy at idle (rattly chain sound) or noisy after a blip of the throttle (while in neutral). To date I have not heard a sound at high rpm under load that I could definately say was a cam chain. If you are concerned about the chain tension, pull the valve cover and have a look at the chain. See if there is any slack behind the intake cam while you turn it over. Also, turn the motor over backwards, and see if the chain climbs the teeth of the sprockets. You can manually click the tensioner in by removing the bolt in the back of the tensioner (the spring and a spring locating rod will come out) and using a skinny blunt metal object to push in the plunger a click. I DO NOT RECOMMEND ANYBODY DO THIS UNLESS YOU HAVE DONE THIS KIND OF THING BEFORE. You could easily over tension the chain, and very bad things will happen. You say your noise occurs at high RPM...this is when the oil dampening portion of the updated and current tensioners is working at its best, and even if the pressure may not be enough to push the plunger in another click, it should act as some kind of dampening device. Let me make it clear that my engine noises are still mysterious (although the more research I do, I seem to be finding them to be common, and I am probably being over paranoid) and that pushing my tensioner in (and later replacing with an APE manual tensioner) did not change any of my engine noises. I've installed many manual tensioners, so I know what an acceptable tightness for a cam chain should be, and the stock tensioner (for whatever reason) did not seem to achieve this.