KZ750-K1 Twin No Spark

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Re: KZ750-K1 Twin No Spark

12 Dec 2018 20:52
#795057
if the previous owner ran 10w30 long term that could have done engine damage for sure.
'78 1000 Long Term Project
 '80 750G
 750 Twin Big Bore Track Bike

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Re: KZ750-K1 Twin No Spark

12 Dec 2018 21:20
#795060
I don't think the previous owner ever had it running well enough to ride. The last registration was 2016 and he never even transferred the title into his name.
1983 KZ750-K1

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Re: KZ750-K1 Twin No Spark

13 Dec 2018 09:28
#795076
I think Scirocco is probably right. i would check your valve clearance and if that isn't crazy far out i would tear it down.
'78 1000 Long Term Project
 '80 750G
 750 Twin Big Bore Track Bike

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Re: KZ750-K1 Twin No Spark

13 Dec 2018 12:47
#795095
So 3 out of 4 were way off. Exhaust Valves were at .127mm and .178 mm and Intake were at .063 and something smaller than .038 (the smallest gauge I had). So I guess it would be worth adjusting these before tearing into the bottom?
1983 KZ750-K1

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Re: KZ750-K1 Twin No Spark

13 Dec 2018 13:30 - 13 Dec 2018 23:55
#795101
Don´t waste your time with the valve adjustment, go tearing into the bottom.

www.z750twin.de/index.htm

(click on the english page button)
It is a helpfull resource for your tear down.
My 1975 Z 1 B 900 Project

www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
Last edit: 13 Dec 2018 23:55 by Scirocco.

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Re: KZ750-K1 Twin No Spark

13 Dec 2018 18:02
#795109
Ok, just because I'm hunting for any reason not to tear into the bottom end ( mostly cause I'm not sure it's worth the effort) would the camshafts being out of time cause this noise? With the crankshaft at TDC the intake cam is lined up, but the exhaust cam is one notch off.
1983 KZ750-K1

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Re: KZ750-K1 Twin No Spark

15 Dec 2018 14:21 - 15 Dec 2018 14:23
#795192
doubtful. if its knocking hard its probably tear down time. I have a bunch of extra parts if you need anything like a crank or whatever
'78 1000 Long Term Project
 '80 750G
 750 Twin Big Bore Track Bike
Last edit: 15 Dec 2018 14:23 by DoctoRot.

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Re: KZ750-K1 Twin No Spark

15 Dec 2018 14:33
#795193
did it sound this bad when you first got it running?
'78 1000 Long Term Project
 '80 750G
 750 Twin Big Bore Track Bike

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Re: KZ750-K1 Twin No Spark

15 Dec 2018 14:48
#795194
It had a massive exhaust leak so it was hard to tell. But yes, it's always sounded off. I found a video on YouTube of a quick way to check rod bearing slack by pushing the piston down slightly on the downward stroke. The right piston didn't move but the left moved noticeably, probably almost 1/4 of an inch.
1983 KZ750-K1

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Re: KZ750-K1 Twin No Spark

16 Dec 2018 12:14
#795231
Here you guys go...you were spot on.

Engine knock
1983 KZ750-K1

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Re: KZ750-K1 Twin No Spark

16 Dec 2018 12:51
#795232
Yup, as i anticipated before. Crank and rod(s) are shot.
My 1975 Z 1 B 900 Project

www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode

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Re: KZ750-K1 Twin No Spark

16 Dec 2018 13:41
#795240
bummer man. If you choose to rebuild the engine I have a crank that you can have for shipping.
'78 1000 Long Term Project
 '80 750G
 750 Twin Big Bore Track Bike

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