Engine Pinging-81 1000LTD, jetting changes?

The engine noise sounds like pinging to me. If you roll open the throttle pulling a hill past 70mph, if held open long enough you'll hear it faintly. It stops immediately when you back off the throttle a hair. In general riding, I would not roll the throttle open that far w/ out downshifting. I did the fuel level check earlier on 3 of the carbs but the #3 has the drain teat snapped off so i couldnt do the level on that one. They were all level w/ the base of the upper carb body. The pinging seems to be more load related than rpm related. I have not tried giving it some choke when it happens and that would seem to tell me if it's a fuel problem or an ignition problem. Good quick test. Thx

I guess I was assuming that the factory may have gone lean on the stock jetting to meet some new emission standards that popped up in the early eighties to go along with the "smog" motor upgrades?

Has a compression test been done?

According to the FSM trouble shooting section for earlier Kaw large four models, it's possible for carbon build-up on the pistons to cause abnormal engine noise, referred to as knocking.

Am uncertain about whether carbon build-up -- with or without excessive compression -- might be responsible for knocking or pinging. But thinking it might be.

Good Fortune!

Another thought - what spark plugs are in the bike? Maybe they're the wrong heat range? Ed

I was thinking abbout that Patton so I checked the compression and found: 150, 150, 140, 150 respectively. When i get home I'll do the choke test and see if that stops the pinging.

Do the dyna 2.2 coils make alot of difference in these old rigs?

Saggs wrote: ...removed and thoroughly cleaned the carbs, set the float height....

Setting float heights is usually done with carbs on the bench, where the clear tube test for fuel level may also be performed, and could swap an undamaged bowl onto #3 carb.

Sorry about the hindsight. :lol:

Good Fortune!

good point. I did it w/ them on the bike. Can the drain screws be purchased still? Mine are pretty cheesed up like alot of the old, soft, Jap metal.

Saggs wrote: good point. I did it w/ them on the bike. Can the drain screws be purchased still? Mine are pretty cheesed up like alot of the old, soft, Jap metal.

According to kawasaki.com, the carb drain screw part no. 92066-1064 on the stock carbs for 1981 KZ1000 LTD is still "active" which means it should be available from a Kawasaki dealership.
Probably have to order it.

Could Google the part no. for other possible sources, and also check with Z1 Enterprises and ebay.

Lots of good info on kawasaki.com, including parts diagrams, part numbers, models sharing same part, availability, etc.

Here's a link for help with navigating the site and finding information.

kzrider.com/index.php?option=com_kunena&...w&catid=13&id=376734

Good Fortune!

Not to insult intelligence, but how fresh (or not) is the fuel ? Possibly water in the fuel ?