saving a 1980 KZ750 twin

thanks guys! this forum has always helped with motivation.
 
Ill square it up on the lathe tomorrow.
 

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That's the job! Now, if you only had a lovely radiused washer to fit under that filet weld under the head . . . .
 
Sorry guys the rainbow is going. It doesn't fit the rest of the bike.
 
Really excellent work all around. I kept an eye on your 1000 project but just found this. Im a really picky guy and each component is something I would use. Well done.
 
First ride was a reasonable success! its got just enough power to be pretty fun, the exhaust has a great tone to it. Not too loud at idle but pretty rowdy when you get on it. The brakes are fantastic. I rode it to my graduation and hooned around a bit there afterwards with my robes on, my parents think I'm crazy. I put about 70 miles on it yesterday.

The jetting is pretty close, think I may need to go one bigger on the main and down a notch on the needle. I'm running into what i think is fuel starvation. When I'm on the highway, after a several seconds of going WOT its starts to miss and wont accelerate anymore like its running out of gas. if i back off for a bit and cruise, it seems like the float bowls refill and I can go WOT for a bit again until it starts missing again. WOT pulls from a stop to 5th gear are no problem its the extended WOT at 60+ where it happens. I have a cheapo petcock, I'm wondering if its not passing fuel fast enough. suggestions?
 

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doc_rot said:
First ride was a reasonable success! its got just enough power to be pretty fun, the exhaust has a great tone to it. Not too loud at idle but pretty rowdy when you get on it. The brakes are fantastic. I rode it to my graduation and hooned around a bit there afterwards with my robes on, my parents think I'm crazy. I put about 70 miles on it yesterday.

The jetting is pretty close, think I may need to go one bigger on the main and down a notch on the needle. I'm running into what i think is fuel starvation. When I'm on the highway, after a several seconds of going WOT its starts to miss and wont accelerate anymore like its running out of gas. if i back off for a bit and cruise, it seems like the float bowls refill and I can go WOT for a bit again until it starts missing again. WOT pulls from a stop to 5th gear are no problem its the extended WOT at 60+ where it happens. I have a cheapo petcock, I'm wondering if its not passing fuel fast enough. suggestions?
Had that same problem on my first KZ1000, it was a small fuel filter for me.


.
 
Get a Pingel for fuel, they have a screen filter already and flow second to none. Congratulations on graduation!!! I love your KZ twin, riding it to graduation was perfect!
 
Thanks guys.

I took the Pingel off my kz1000. At the very least it makes routing the fuel lines WAY easier, and looks a lot better. Unfortunately it didn't solve the problem. I popped the gas cap open and rode it like that as well thinking maybe it wasn't venting properly but that had no change. I'm gonna pull the carbs off and inspect the fuel inlets and float valves. Scratching my head here. suggestions?
 

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So the float valves were 2.0, I switched them to 2.5 and the problem went away. it also richened everything else up and the bike is happier on the whole. Im thinking about switching them to a 2.8 just to ensure the float valve isn't acting as my main jet.

My question is; why would they install small float valves? wouldn't you want to have the biggest possible float valve to ensure fuel delivery, and let the jets do the fuel metering?
 
doc_rot said:
So the float valves were 2.0, I switched them to 2.5 and the problem went away. it also richened everything else up and the bike is happier on the whole. Im thinking about switching them to a 2.8 just to ensure the float valve isn't acting as my main jet.

My question is; why would they install small float valves? wouldn't you want to have the biggest possible float valve to ensure fuel delivery, and let the jets do the fuel metering?

Doc, where did you find the new ones? I've had the same nagging issue on mine...too rich one day, too lean after the next change...made me so nuts I put her away for a while....
 
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