loud drivetrain knock

I recently bought a 1982 kz750m1 csr. It sat inside for 7 yrs, then outside for 2. The PO said it was in need of a timing chain adjustment. After rebuilding the starter clutch and carbs and then cleaning the carbs over and over and over, it now runs amazing except for one problem, It has a terrible knock. It sounds like a rod knock, but it only happens in gear and under load. I suspect the primary chain or the balancer. Im ruling out bearing issues because in nutrual i can rev the piss out of it with no knock even when hot. Just looking for confirmation so i can justify the engine teardown.

Can you post a video of it?
Steve

I can try later today. Theres a hill by my house that it always does it on.

Havnt got a chance to video it yet. Today is dedicated to the bathroom remodel. I did talk to my dad though and i think im just going to go ahead with pulling the engine and splitting the case. Ill try to post pictures of what i find so others can benefit. Any suggestion of where to source parts other that z1enterprises and ebay? Z1 doesnt seem to have a big selection for the 750csr twin. What other kz750s shared engines with the M1? Thanks.

, It has a terrible knock. It sounds like a rod knock

Bad pinking - detonation, under load can sound mechanical. Maybe try to tweak the ignition timing a touch to eliminate this?

Ill take a look at the timing advancer, but im pretty sure all you can do it clean it. I cleaned it and made sure it operated properly when i bought the bike, but ill check it again. Would much rather it be a timing issue than have to open the engine up.

What octane fuel are you using? If you're using regular or mid-grade try running a tank of high octane to see if knock is reduced or gone. If so, the noise is detonation so maybe the ignition timing is off a bit. Ed

Jankog wrote: Havnt got a chance to video it yet. Today is dedicated to the bathroom remodel. I did talk to my dad though and i think im just going to go ahead with pulling the engine and splitting the case. Ill try to post pictures of what i find so others can benefit. Any suggestion of where to source parts other that z1enterprises and ebay? Z1 doesnt seem to have a big selection for the 750csr twin. What other kz750s shared engines with the M1? Thanks.

Although silly, I keep the KZ750 twin models identified by using the acrostic phrase:
My Kawasaki By God.


Kawasaki KZ750 750cc 4-cycle twin
1976 Kawasaki KZ750-B1
1977 Kawasaki KZ750-B2
1978 Kawasaki KZ750-B3
1979 Kawasaki KZ750-B4
1980 Kawasaki KZ750-G1
1982 Kawasaki KZ750-M1
1983 Kawasaki KZ750-K1
1984 Kawasaki KZ750-K2


Per KZr member, steell:
76-79 KZ750 were the "B" model, single disc front and rear with wire spoke wheels.
1980 KZ750G, pretty much the same as the "B", but with rear drum brake and mag wheels.
1981 model 750 twin doesn't exist.
1982 KZ750M1 CSR, same motor as the "B" and "G", with air injection into the exhaust, with wire wheels and rear drum brake.
1983 KZ750K1, same as M1 except for belt drive.
1984 KZ750K2, Canada only, same as K1.

Good Fortune!

Spark plug readings?

Spark plug readings per throttle chop test?

Perhaps post a photo of the business ends of spark plugs?

Good Fortune!

The K1 and K2 (LTD) had mag wheels.

Thanks for the reference info! I havent done anything with the bike the past couple days aside from start it up. Now its not running well. Doesnt seem to want to run off of the enrichment circuit. I am planning on checking out the timing situation just to make sure that isnt it. If it is, i will be surprised though. The noise sounds very mechanical. Something is wrong with my starter now too. I rebuilt the starter clutch, but now it will turn over a couple times, and then just grind. Will be removing the actual starter soon. I will try to get pics of the plugs, although i need to get a new set. The old ones were totally black because the carbs werent operating properly. Ill do another sync and set the pilots again, throw in new plugs and get pictures. Thanks again for the help!

Jankog wrote: Now its not running well. Doesnt seem to want to run off of the enrichment circuit.

Usually a sign of clogged low speed circuits, air leaks around the intake manifolds (boots), or both. Do you have a good inline fuel filter? If not, some crud from the tank may have recontaminated your carbs.