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1977 KZ650 not running properly
- James027
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here are the exhaust temp after idling for 5 minutes: 1= 150F 2= 200F 3= 230F 4= 250F
This is just estimates as I took those measure with a cheap infrared thermometer and it always fluctuate).
I first though that #4 was the one running better but after some reading here it may be that this one is running lean (like folks having gold exhaust from running lean). Can someone explain a little about that?
#1 need work and #4 isn't right also. How to know what would be the good exhaust temp? (I guess it's not about getting a specific exhaust temperature but it helps figure out how it's running).
Another issue I have. I need to adjust the idle many times as it warms up. I turned it down maybe one turn after every minute I drive and stop (short test drives) Once again that's just a figure. Do you play with that screw often (everytime you ride) or once the idling speed is ok there's no need to mess with that? Do you start it on choke and once you turn it off the idling speed is ok? I sprayed carbs cleaner to find a vacuum leak but can't find any!?
Also, when I get the idle lower than 2000 rpms the engine run kind of rough and I can hear the primary chain (I guess) making noise.
I read the SM but don't wanna go through all the step of synching the carbs and all those adjustements without knowing it would fix my problems. I don't have much time to spend on this and I need the bike to go to work asap.
Thanks for your help!
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- 650ed
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It is possible that the carb cleaning missed some little orifice, but before you go through the trouble to pull and re-clean the carbs I would highly recommend you sync the carbs. If one or two carbs are open significantly more than the others the idle will be affected, the primary chain will make a lot of noise at idle, and the cylinders will run at different temperatures. If you have access to a sync tool or proper gauges syncing the carbs is a very easy process and does not take long to do. As you sync the carbs you should be able to lower the idle speed to a normal rate. At that point you can perform the leak test again and see if it reveals anything.
You should not need to fiddle with the idle speed adjuster during a ride once the carbs are properly tuned and there are no carb holder leaks.
Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- Patton
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James027 wrote: ...I read the SM but don't wanna go through all the step of synching the carbs and all those adjustements without knowing it would fix my problems. I don't have much time to spend on this and I need the bike to go to work asap....
Could be helpful to first determine how far the carbs are out of sync.
Just hook sync hoses to the vac nipples and read the results.
Might already be perfect. -- Fat chance! :lol:
Good Fortune!
1973 Z1
KZ900 LTD
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- James027
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I took a few shorts ride and it seem ok on the road but the bike wasn't starting so well. My main concern is that it takes some time before I can open the throttle (the engine dies if I only try to twist it a little). I connected a small bottle of gas to the #1 carbs holder so it can idle faster and finally be able to give throttle (and then go for a short ride).
I messed around with the pilot screws after reading that when warmed up, I should notice a change in rpm and make adjusments this way. But there was no noticeable changes and I think a messed up my pilot screw too much. Now the bike won't run over 5 seconds!! It start pretty good but die shortly after. Fuel suply is okay (I even did a test with a bottle to replace my tank) but nothing change.
Do you know another way to adjust those screws with the engine stopped? Mine are a bit worn out, is it so bad? Also do you have a file for the section of the service manual that talks about that (or maybe a link to a complete manual). I only have the manual for the 78 and up that use mixture screws.
That let me think that I got 2 set of carburators with mixture screws. They are dirty and need works (and probably parts) but are they better than the older carbs with pilot screws? Should I use them instead?
Thank you very much for your help!
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- James027
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- Patton
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Here's one cleaning method.
Good Fortune!
1973 Z1
KZ900 LTD
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- Patton
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Objective -- with either pilot air screw or pilot mixture screw -- is to assure the fuel mixture enters the bore as it's supposed to (through the small orifice, or orifices, as the case may be).
Good Fortune!
1973 Z1
KZ900 LTD
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- James027
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Some pilot screws are worn out thought. I'll send some pics so you can tell me if I absolutly need to replace them.
Thank you!
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- James027
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Enough writing now. It's a beautiful evening to enjoy a long ride
Thank you!
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