Noise on take off

I finally have the KZ running up and down the road. I’m getting a noise that I can best describe as a low pitch, low frequency rumble or rattle, or maybe even a light knocking. It occurs when you first take off and it’s worse if you lug the engine. If you keep the PRM up or slip the clutch a little the noise is less pronounced and almost non existent. You can also get the noise if you lug the motor in higher gears, for example running 2000 RPM in 5th gear and open the throttle a little. Bring the RPM up and get the engine pulling and the noise goes away. My sons KZ 1000 makes some similar noises in the same conditions, but to a far lesser degree than my bike.

I’m thinking I need to pull the clutch cover and verify that all my clutch components are tight and not “loose on the shafts” so to speak. Is there anything else or some additional testing I need to do to run this noise down? Am I missing something and this noise not be related at all to the clutch assembly?

Thanks in advance for your thoughts and assistance.

hi,
I honestly don't know.Under load knocking is main bearings,but you describe something else.My old yamaha sounded like a table being pushed accross a hardwood floor when taking off.Never did figure it out.I think your on the right track checking clutch basket.
come on KZRIDERS,help this guy out.Don't worry JD,they'll come,they love to help.some of these guys really know their shit.
cool,another chance to post my pic! :laugh:
carter,kansas city

Your description sounds like detonation to me. Are you using premium fuel and is the ignition timing set correctly? Ed

Sounds to me like the problem I had with my starter motor clutch-which I repaired and cured the noise. Look up a thread called "Terrible noise" it will describe roughly the same thing you are experiencing.
Grant.

I dont know really, but do you really hear it just around idle also, and does it sound like or feel like something is jumping up and down in the crank area, real heavy like. If so, it sounds like excessive bearing play in the crank area. Put your hand on the engine cases, alternator and points cover and you just might feel it thumping in there.

My experience says cam chain. Simplest answer, don't do that. Use a few more revs to get it going! If that's all it takes, learn to adjust.

I've been riding KZ's for 32 years. A couple of years ago I got on a 1980 GL1100 and had to totally relearn my launch procedure. Once I learned that the bike needed more revs to launch, I was very pleased with the power.

KZCSI

Thanks for the replys. Here's the answers to your specific questions.

650ed : The timing is correct. I'm using ethanol enhanced premium but I may try adding some octane booster for a test.

Grantl: I'll look it up.

kzwolfsr : I can get a little rattle out of it if I back off the idle adjustment until it just barely will idle.

KZCSI : I know the cam chain isn't loose, I adjusted it 2 weeks ago when I run the valve adjustment.

Thanks again

Loose starter clutch rollers, or bolts, will rattle at idle and up to 1500 rpms or so then go away as speed increases. This problem drove me crazy for several years until I discovered what it was, the bolts were loose. chris3

dont use the octane booster crap,, it does not blend evenly with the fuel and can cause damage, I holed a piston once using that crap.
mine will make strange noises when it gets lugged down, the motor was not designed to have that happen to it, it wants to see some rpm, I would guess you are hearing a combination of cam chain, and detonation, among other things.it is creating harmonics throught the engine that it dosent like

"Loose starter clutch rollers, or bolts, will rattle at idle and up to 1500 rpms or so then go away as speed increases. This problem drove me crazy for several years until I discovered what it was, the bolts were loose. chris3"

I think I'll start be pulling the rotor and checking the bolts. I'd have done it this evening but I managed to destroy my old cheap impact driver on a Kia Sorento today. Snappy will be by Tuesday with a new one.

Thanks again for the replies.

John, Some decent advice in this thread and some poor advice. With your 8:1 compression, I doubt you have detonation as the KZ engine will almost run on anything. It doesn't LIKE hi-test or more octane which retards combustion.

OK... you have an old KZ engine. I have NEVER seen an old KZ engine that didn't have a cracked/broken/missing front cam chain bumper, old and very hard/cracked idler assembly dampers and probably a tired/shot lower/center roller. The noise probably won't hurt anything but when I buy an old KZ, I open up the engine and replace ALL the cam chain bits I can including the old, stretched chain.

About the only thing you can do without taking the engine apart is to tension the cam chain and replace the dampers on the idler assembly. If the chain is still loose and the noise is annoying, you can replace the chain which might help some by using a master-link style chain.

The 1015 engine connects the crank to transmission by gear drive so you won't have the extra chain the 650 does... it also helps to pay attention to where the noise is coming from... if the starter clutch or stator is rattling, that will come from the lower left side where the cam chain rattle is more centered.

Thanks again for the information. I added a little octane booster and noise was definately reduced. I drained the tank and refilled it with premium from the shell station and now the noise is down to a very little rattle coming from the left side right behind where the side cover meets the engine case. I think maybe the worse problem was just some bad gasoline. (I should have looked there first....as often as I've seen bad gas in cars.)

I'm hoping to ride this summer and take care of the cam chain issues this winter with a top end O/H.

Thanks again for the help.