Engine rattle

yes,i have a 750 four cylinder, shaft driven.

Could it be spark knock? Check your timing, and/or advance to make sure it is working properly. Just A Thought.

You said they adjusted your valves. Did they reset the cam chain tensioner also, correctly? I just did my cam chain and at first it was wrong and the rattle was horrible. I redid the tensioner and it definately made a difference.

the receipt said nothing about resetting the cam chain tensioner. Is the cam chain the same as the primary chain? i was told that the primary cahian has no tensioner.

i just got my repair manual today and looked up the cam chain tensioner. If it is the problem, wouldn't the noise be there all the time? It seems that temperature is a major factor higher, the colder it is the louder the noise. Could it be an oil problem? Once the oil gets hot enough to flow the noise goes away?

If it was the cam chain, then the noise would be there all the time.
How loud is "loud"?
Can you hear it from 50 feet away? a 100 feet? A block away? Does the noise sound like someone striking a block of iron with a hammer? Marbles in a tin can?
Use a hose and locate the point where the sound is loudest.

KZ's make all kinds of different noises and for different reasons, so you need to be as specific as possible.

steell wrote:

640x480 works

you win:laugh:

you could hear it within 30 feet of the bike. It does sound like marbles in a tin can. I just got the repair manual, so I'll try to locate the noise with the garden hose trick and give a more specific location.

Once again, thanks for all the input. This bike will be resurrected if its the last thing I do. My father bought this bike brand new in 1983 and gave it to me. I just let it sit and now with only 4,000 miles on it, I'm getting a hard on for it,(figure of speech). Especially with my friends buying $25,000 Harleys, this Kawi is going to be around for a long time.

okay,
sat there with the garden hose stethoscope and I think I'm pretty sure the exact location of the noise.
On the left/bottom side of the motor, in the area of where the "1N2345" is inscribed. The noise is actually behind the "1N2345", towards the bottom. Hope this helps.
Thanks.

That cover comes off pretty easy, and all that's behind it is the sprocket and the clutch release mechanism.
The bearing for the engine countershaft is also behind that cover, and the primary chain drives the engine countershaft.
You said that pulling in the clutch and putting it in gear does not affect the noise, so that eliminates the sprocket and transmission shafts (they won't be turning when you do that).
If you take that cover off then start the motor, and put the end of the hose against the little (about 2") round cover that's in front of the sprocket, I suspect that you will find the noise is louder. That little cover is over the engine countershaft bearing, and that indicates the noise is coming from the primary chain.

As long as the noise goes away when it warms up, I would not worry about it. When it makes noise all the time, then I'd consider replacing it.

Replacing the primary chain involves removing the motor, splitting the cases, and removing the crank and countershaft, and you can probably buy two used motors for the money that it would cost you to have a shop do that.

Post edited by: steell, at: 2006/03/16 17:32

I've had two kaw 750 fours. An 82 kz750 and an 84 kz750L4. Both these engines had the primary chain noise which sounds like a knock/rattle at idle.If the throttle was opened slightly to raise the idle and smooth the power pulses the noise would dissapear.Rode them for years without any problems.

im about to change the oil. What weight should I use? Should i use synthetic or stick with conventional? Would a thicker oil or a thinner oil quiet the engine rattle noise?
I do little riding, mainly around town, low rpm's.