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get a picture of the left side of the cams at TDC and again at TDC 360 degrees later.

Lobes should be evenly opposite..
 

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Discussion Starter #22
Excessive fuel consumption would lead me to believe its a carb issue, but if it will still rev up okay in neutral i'm at a loss. Does your oil smell like petrol ? That would tend to indicate a float problem and the carbs are just dumping fuel into the cylinders. Usually the bike won't run at all but since you say it starts better cold (where you need more fuel) than hot may indicate that its flooding but not to such a severe degree that it won't run at all.

Does your exhaust warm up quickly ? Cold header pipes would also indicate a overly rich fuel condition.

If compression checks out and cam timing is okay, fuel and spark are really the only things left. How new are your spark plugs ? I had an issue years back where my bike was running kinda shitty, the plugs looked okay for the mileage but testing revealed weak spark. Changed them out and the bike was back to normal.
The oil does smell of gasoline. Its weird that the carburetor suddenly starts to flood, there was nothing wrong with it before. I havent checked the compression yet, gonna buy a tester tomorrow and check how it turns out. If there is low compression, it should be the valves, because the rings are brand new.

Spark plugs are pretty much brand new, maybe 7 hours of use.. I have heard with a workshop to synchronize my carb and check the valve clearences. Waiting for them to give me a price estimate.

if your cam timing is off a tooth, this can also create a problem.
The cam timing might be off a tooth, but Seemed to be good before i put the engine in the frame. I might take off the valve cover and check it again. The seller told me he used even thinner than stock gaskets, something like 0.09mm he said. but there is no way that would make this big of a difference. not even sure how he managed to get thinner gaskets..? He belives the timing is off
 

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Discussion Starter #23
Excessive fuel consumption would lead me to believe its a carb issue, but if it will still rev up okay in neutral i'm at a loss. Does your oil smell like petrol ? That would tend to indicate a float problem and the carbs are just dumping fuel into the cylinders. Usually the bike won't run at all but since you say it starts better cold (where you need more fuel) than hot may indicate that its flooding but not to such a severe degree that it won't run at all.

Does your exhaust warm up quickly ? Cold header pipes would also indicate a overly rich fuel condition.

If compression checks out and cam timing is okay, fuel and spark are really the only things left. How new are your spark plugs ? I had an issue years back where my bike was running kinda shitty, the plugs looked okay for the mileage but testing revealed weak spark. Changed them out and the bike was back to normal.
get a picture of the left side of the cams at TDC and again at TDC 360 degrees later.

Lobes should be evenly opposite..
Took off the cover and checked the cams. It seems to be correct, only weird thing i noticed was when i turned the engine i could hear the compression go inside of the engine, instead of out of the exhaust. This might just be my mind playing tricks with me though. Thought maybe the rings had broken, so that all the compression goes down into the crankcase. But i highly doubt it, because i tried starting the bike without the oil filler cap on, and all of the oil stayed in the crankcase, nothing came out.

There is one thing i know i didnt do when swapping to the new head, and that was going over the valves and shimming them. I thought it would be good to go since it was allready been used. Maybe the inlet and exhaust valves open at the same time, so that the gas goes in and straight out of the exhaust without burning it? This might explain why it drinks like a camel and runs like shit.

Also, is it normal that the lines on the cams doesnt line up like the other side, when its been turned 360 degrees. Check out the pictures and you can see the comparison off the right side of the cams, where the "in/ex" text is vissible and when its gone. Hard to explain :)

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The crankcase noise is normal

The lobes look close, a compression test will confirm. (hold throttle wide open so the butterfly doesnt restrict air flow, or pull them off completely)

The just check clearances, and make sure there is sone sort of gap.

The lines on the cam gears are kinda offset, and have been degreed, so the stock references don't appy
 

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Discussion Starter #25
The crankcase noise is normal

The lobes look close, a compression test will confirm. (hold throttle wide open so the butterfly doesnt restrict air flow, or pull them off completely)

The just check clearances, and make sure there is sone sort of gap.

The lines on the cam gears are kinda offset, and have been degreed, so the stock references don't appy
The crankcase noise is normal

The lobes look close, a compression test will confirm. (hold throttle wide open so the butterfly doesnt restrict air flow, or pull them off completely)

The just check clearances, and make sure there is sone sort of gap.

The lines on the cam gears are kinda offset, and have been degreed, so the stock references don't appy
Tested the compression today, this was the results with cold engine and carbs removed, tested each cylinder twice.

From left:
1) 180/180
2) 175/174
3) 181/183
4) 174/171

acording to the manual it should be between 138 - 210 psi. Guess im within the standards. :)

Then it must be a carburetor issue.. or?
 

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Discussion Starter #27
those are great numbers ....yes, seems like a carb issue.
Gonna have give it to a shop to get the carbs synched and properly jetted. Hopefully this will solve the mystery,

Just dont understand why it revs fine when in neutral, and bogs down when trying to take off. Very weird
 

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Discussion Starter #28
Do you think its necessary to use bigger jets after changing the cams and porting the head? :)
 

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After you get it fixed and going you might want to consider disconnecting the TPS on the carb. It will default the ignition map to maximum spark advance.

Jake filled us in on that trick many years ago and it did produce a noticeable result for me. There was a thread on the forum here, but some jerk that thought he knew more than Kawasaki and verified test bench results decided to shit all over the thread and got it locked. I have the relevant info archived here -

https://klxworld.blogspot.com/2017/07/kawasaki-k-tric-carb-information.html
 

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Discussion Starter #30
After you get it fixed and going you might want to consider disconnecting the TPS on the carb. It will default the ignition map to maximum spark advance.

Jake filled us in on that trick many years ago and it did produce a noticeable result for me. There was a thread on the forum here, but some jerk that thought he knew more than Kawasaki and verified test bench results decided to shit all over the thread and got it locked. I have the relevant info archived here -

https://klxworld.blogspot.com/2017/07/kawasaki-k-tric-carb-information.html
Sweet, i tried to run the bike without the tps connected, but it didnt affect the running issue. Will test it out when i get the bike running properly! :)
Thanks for sharing
 

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bigger jets may be needed, or smaller.

When the vacuum in increased from efficient air flow, it also draws more air up through the jetting holes in the carbs.

Carb Tuning is kinda an art form, using a A/F meter it relieves some of the mysteries, but still there are some fine lines to get it right once the main jet and needle is sorted.
 

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bigger jets may be needed, or smaller.

When the vacuum in increased from efficient air flow, it also draws more air up through the jetting holes in the carbs.

Carb Tuning is kinda an art form, using a A/F meter it relieves some of the mysteries, but still there are some fine lines to get it right once the main jet and needle is sorted.
To add to Jakes comment, increased vacuum can also alter the carb slide response, so needle and slide adjustments may need to be made too.

When I installed a 331 big bore kit on my KLX250 I actually had to dial the jetting back a bit since it was now too rich at mid throttle opening with the carb settings I had been using on the 250cc bore. I actually bumped the main jet up a size to fix lean out at wide open throttle, but had to drop the needle all the way down as well as reinstall the factory slide spring since the increased vacuum was pulling the slide up too easily and causing a rich condition.

Welcome to the wonderful world of carbs. :)
 

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Discussion Starter #33
bigger jets may be needed, or smaller.

When the vacuum in increased from efficient air flow, it also draws more air up through the jetting holes in the carbs.

Carb Tuning is kinda an art form, using a A/F meter it relieves some of the mysteries, but still there are some fine lines to get it right once the main jet and needle is sorted.
To add to Jakes comment, increased vacuum can also alter the carb slide response, so needle and slide adjustments may need to be made too.

When I installed a 331 big bore kit on my KLX250 I actually had to dial the jetting back a bit since it was now too rich at mid throttle opening with the carb settings I had been using on the 250cc bore. I actually bumped the main jet up a size to fix lean out at wide open throttle, but had to drop the needle all the way down as well as reinstall the factory slide spring since the increased vacuum was pulling the slide up too easily and causing a rich condition.

Welcome to the wonderful world of carbs. :)
I remember when i was younger, i used to tune mopeds, which is a big thing here in europe. Bought bigger cylinders (from 50 to 80cc), stronger crank, bigger carbs (from 17.5 dellorto to 28 Mikunis), more effecient ignition and exhaust. There were great power outcomes, from 4hp to 30ish.
This also required some jetting and test riding, but after a while it got right! This was single cylinder and when i started fiddling with the carbs on the ZX it brought back some good memories. But after dissasembling and reasembling these carbs for the 100th time i also remembered how damn annoying carbs really are. BUT!!! its running good now! rode for about 15 miles, everything seems good! found 2 oil leaks, the ignition rotor case and valve cover needs re-tightening.

It sputters for 2 seconds when starting up when its warm, and a bit hard to start. but idles fine after that. Also i can feel a big drop in torque down low in the rpm, havent tried pushing the bike hard just yet. want to ride in the new rings first! :)

I might put up a riding video, but we'll see. :)
 

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I remember when i was younger, i used to tune mopeds, which is a big thing here in europe. Bought bigger cylinders (from 50 to 80cc), stronger crank, bigger carbs (from 17.5 dellorto to 28 Mikunis), more effecient ignition and exhaust. There were great power outcomes, from 4hp to 30ish.
This also required some jetting and test riding, but after a while it got right! This was single cylinder and when i started fiddling with the carbs on the ZX it brought back some good memories. But after dissasembling and reasembling these carbs for the 100th time i also remembered how damn annoying carbs really are. BUT!!! its running good now! rode for about 15 miles, everything seems good! found 2 oil leaks, the ignition rotor case and valve cover needs re-tightening.

It sputters for 2 seconds when starting up when its warm, and a bit hard to start. but idles fine after that. Also i can feel a big drop in torque down low in the rpm, havent tried pushing the bike hard just yet. want to ride in the new rings first! :)

I might put up a riding video, but we'll see. :)
Awesome ! Glad to hear you got it sorted out.
 
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