How I fixed my KZ engine problems (after a year!)

Hi,

After a year of troubleshooting on my GPZ 750 R1 1982, i think it (the solution) deserve to be explained here for further reference!

Previous long thread explaining what i did have --- > kzrider.com/forum/2-engine/460495-solved...nstallingoverheating

In short:

Engine has been overbored (scratch damage) to fit the wiseco 810cc piston kit

-Engine running rough at on long stop/red lights (drop from 1100 rpm to 700 rpm , fluctuate)

-Engine would halt on hard braking (nearly stoppie!)

-Engine would halt running rough for too long (red lights)

-Engine Abnormally hot

What has been checked hundreds of time

-Idle speed
-Carb sync
-Spark coils
-Fuel level
-Valve clearance
-Leaks Leaks!!!
-Clutch adjustment
-Jetting
-CDI box
-Pickups & mechanical advancer

I spend a lot of money changing the following parts while praying its gonna fix something:

-Spark plugs coils & wires (dyna coils)
-Ordered from #110 to #145, over 50 main jets (yes! fifty pcs)
-Spark plugs, NGK BR9EIX iridium
-Intake boots and airbox boots
-New regulator/rectifier (had already one thought)
-New battery
-Changed electrical connectors

Enough listing!:laugh:

Ok so when i was again on a spending spree on Z1Enterprises decided to purchase new clutch plate,steel plates, APE bearing push rod and clutch springs.

Boy the clutch was partially the culprit of all my troubles !

Plates where distorted and always dragged a little at any clutch play , adjustment possible!

Enough to stall the engine sometimes when plates sticked together in gear (at stops)!



Another thing which misled me, i think it was never described here that's why it was for me Counterintuitive...


Exhaust will backfire , pop and crackles when TOO RICH! (damn it!)
Everyone was describing this as a TOO LEAN problem ... no, not on my bike

I raised from #135 and kept rising until #145 when i found in a car forum about carb adjustment that too rich will cause this symptoms instead of BOGGING like people describe here

So switched to #132.5 and everything's fine ... yay! Got plenty of main jets to sells



Another cool thing i found... you can change the float level, main jets and pilots jet on BS34 while installed! (airbox , no pods)

You must have patience thought ... this prevented from wearing my intake boots,collar and airbox boots from removing and installing the carb rack too often!

A big bonus no carb sync required since you never removed them!

My heart is empty and my pocket too now

hope this helps!

best regards,
laurent

Way to stick with it and finally find the solution!

Good to know. Thanks for the follow up!

Patience is truly a virtue. Boy! You really had some obscure issues. This why I enjoy reading these posts so much. Always something to be learned. Way to hang in there.

What tipped you off that it was the clutch?

Excellent post Laurent! Thanks.

What tipped you off that it was the clutch?

The primary chain was rattling like a gatling gun (once in a while) when in red light in first gear !

In neutral it was okay all the time but switching to neutral while moving when coming to a red light is hardcore!

Excellent post Laurent! Thanks.

Yeah thanks Mcdroid , your KZ750 R1 seat you sold to me last year still hold very well btw

regards,
laurent

this is good to know , somewhere else to look, I still have issues with my bike recovering an idle at stop signs when hot, and I eliminated the possibility of heat boiling the gas in the carbs. Glad you got your problem fixed, enjoy the ride.

Godfrey wrote: ...I still have issues with my bike recovering an idle at stop signs when hot, and I eliminated the possibility of heat boiling the gas in the carbs....

Often results from too tight valve clearances.

Good Fortune!

this is good to know , somewhere else to look, I still have issues with my bike recovering an idle at stop signs when hot, and I eliminated the possibility of heat boiling the gas in the carbs. Glad you got your problem fixed, enjoy the ride.

One thing you should try...whenever possible switch to neutral at stop or when coming to a stop to see if it make a difference ... could be that too

clutch drag is possible like i had with the warped plates

regards,
laurent

glad to hear u have solved the problem.
its good to hear about the cure after so much hard work.
Well done.

It seemed I was lucky when I got back into the old bikes,mostly carb cleaning. The more bikes I bought the more problems that came up.

I finally got very good at trouble shooting. I guess that's what it amounts to,trouble shooting.

One year at the meet in Ohio Andy brought a 650 that had given him trouble for a long time and would not start.

I tried to start it and after installing a set of carbs I had and it still would start I removed the gas tank and switched the coil wires and it fired right up.

After a while (years) :blink: a person will become good at the trouble shooting.

What I see most on the site is someone asking advice and not applying the years of expierence of riders thet have gone through the same issues.

I understand when someone doesn't want to adjust valves but if the valves need adjusting,they need adjusting. This one issue will affect so many areas that one will want to give up.


I followed your thread on this bike and I applaud you on hanging in there until you have found the problem and expanded your experence level to a degree where the bike is so familar to you that any problem after this will be a breeze. Roy