Kawasaki Forums

Kawasaki Forums (https://www.kawasakiforums.com/forum/)
-   General Tech (https://www.kawasakiforums.com/forum/general-tech-9/)
-   -   throttle or carb problems (https://www.kawasakiforums.com/forum/general-tech-9/throttle-carb-problems-16478/)

sbdiehl 10-17-2007 12:33 AM

throttle or carb problems
 
the throttle on my '78 kz650 is going crazy. when i clutch between gears it revvs up to about 4 grand and stays there for a bit, then eventually goes down to idle and dies if you let it idle too long. its definitely not me doing it by accident. i know that someone who owned the bike before me had the bright idea of boring out the carburetor jets to get more fuel, but now it runs too rich. do you think that could be why the throttle cranks by itself like that? i ordered some pod filters to replace the intake box, with hopes that getting a little more airflow will help smooth out the mixture. is there a way to turn down the fuel ratio on the carbs? any suggestions would be helpful! thanks

sbdiehl 10-17-2007 12:34 AM

RE: throttle or carb problems
 
also the warmer the engine gets the worse the problem gets, it revvs up every time you clutch and once it idles it dies almost instantly

davehayward1 10-17-2007 12:54 AM

RE: throttle or carb problems
 
Don't know if this would cause the problem but..........
My '81 KZ 750 LTD was having a problem...............
It would run fine for a while and after a few miles, once it was warmed up, it would lose power.
The problem was improper suction of fuel from tank into the carbs.
The mechanic removed the valve /switch that controls flow from tank to carbs and rebuilt the
mechanism inside (it is located directly under the gas filter inside the tank)
If this isn't functioning properly, couldn't it cause the flow of gas to increase and decreas randomly, causing the revving
and stalling you describe?
Maybe someone knows more about this than I and can describe it better.
Good luck

markmeinteil 10-17-2007 12:58 AM

RE: throttle or carb problems
 
Actually, it's running too lean. Engines like to race when they have a lean A/F ratio. Too much gas causes them to bog down. Small engines such as motorcycle engines tend to have more dramatic aftereffects from small changes like an aftermarket pipe, or a modified airbox. It is also very possible your float bowl levels are way too low. That too would cause a lean A/F condition.

markmeinteil 10-17-2007 01:00 AM

RE: throttle or carb problems
 

ORIGINAL: davehayward1

Don't know if this would cause the problem but..........
My '81 KZ 750 LTD was having a problem...............
It would run fine for a while and after a few miles, once it was warmed up, it would lose power.
The problem was improper suction of fuel from tank into the carbs.
The mechanic removed the valve /switch that controls flow from tank to carbs and rebuilt the
mechanism inside (it is located directly under the gas filter inside the tank)
If this isn't functioning properly, couldn't it cause the flow of gas to increase and decreas randomly, causing the revving
and stalling you describe?
Maybe someone knows more about this than I and can describe it better.
Good luck
Very good point also. Those old vacuum diaphragms could give you problems too. Easy rebuild if that is it.

Dragone#19 10-17-2007 02:11 AM

RE: throttle or carb problems
 
Un synched carbs can cause similar issues as well.

sbdiehl 10-17-2007 02:18 AM

RE: throttle or carb problems
 
great. i dont know how to fix those problems... it doesn't make sense that its too lean though, if the carb jets are bored out... does it?

sbdiehl 10-17-2007 02:22 AM

RE: throttle or carb problems
 
i'm not much of a mechanic and i've never worked on a bike before, but i do enjoy getting my hands dirty. is there any way to adjust and sync the carbs that i can do without paying someone alot of money to have it done at a shop?

Dragone#19 10-17-2007 02:23 AM

RE: throttle or carb problems
 
bored out jets. Good point. so install stock mains and try to get a baseline.

markmeinteil 10-17-2007 02:39 AM

RE: throttle or carb problems
 
It could be somethingnon jet related tocause the engine to lean out though. It isn't always the usual suspect. Your engine having a hard time returning to idle is a classic example of running too lean. But having said that, it still COULD be something else, but not very likely.


All times are GMT. The time now is 10:52 PM.


© 2024 MH Sub I, LLC dba Internet Brands