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Having trouble w/ ? Runs like a bat outta hell for 20 miles, then dies...like fuel restriction.... carbs rebuilt 90 miles ago & adjusted for this issue but still exists... affects ALL carbs so gotta be fuel? Throttle cable? Gas tank venting? HELP please馃檮
Did you check your float bowl levels? Full tilt bozo runs will run bowls dry if not at the proper level (which will caused it to run lean as they run dry). However, the boggin sounds like wet fouling of the plugs possibly(plugs will tell). Either from too much oil or way fat on the main or needle(plugs will tell). If its lean, you can get a partial seizer and that will cause it to bindup..same symptom, boggin as the piston seizes(again plugs will tell). What every it is I wouldn't ride it until you get it figured out or you might toast the engine.
 

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Discussion Starter #42
Again, thank you all for continuing to think about my problem while i have been sweating my %#* off rebuilding a fence馃お

rain for the next 2 days, then I will be aggressively pursuing the issue again... starting w/ spark tests & checking plugs馃槉
Did you check your float bowl levels? Full tilt bozo runs will run bowls dry if not at the proper level (which will caused it to run lean as they run dry). However, the boggin sounds like wet fouling of the plugs possibly(plugs will tell). Either from too much oil or way fat on the main or needle(plugs will tell). If its lean, you can get a partial seizer and that will cause it to bindup..same symptom, boggin as the piston seizes(again plugs will tell). What every it is I wouldn't ride it until you get it figured out or you might toast the engine.
Did you check your float bowl levels? Full tilt bozo runs will run bowls dry if not at the proper level (which will caused it to run lean as they run dry). However, the boggin sounds like wet fouling of the plugs possibly(plugs will tell). Either from too much oil or way fat on the main or needle(plugs will tell). If its lean, you can get a partial seizer and that will cause it to bindup..same symptom, boggin as the piston seizes(again plugs will tell). What every it is I wouldn't ride it until you get it figured out or you might toast the engine.
Well....can鈥檛 complete diagnosis w/o running to (quit mode).... carbs, floats, fuel lines all less than 150 miles out of u/s cleaning & reassembly by kawasaki dealer....if cyl heads are full of unignited fuel, no place for new fuel to flow but out....
 

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Discussion Starter #43
Have considered too rich fuel and eventually too much for spark to handle..... next step is spark test & pull plugs while sitting on the roadside to see if wet, moist or brown馃お
 

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Again, thank you all for continuing to think about my problem while i have been sweating my %#* off rebuilding a fence馃お

rain for the next 2 days, then I will be aggressively pursuing the issue again... starting w/ spark tests & checking plugs馃槉


Well....can鈥檛 complete diagnosis w/o running to (quit mode).... carbs, floats, fuel lines all less than 150 miles out of u/s cleaning & reassembly by kawasaki dealer....if cyl heads are full of unignited fuel, no place for new fuel to flow but out....
I hear you, but understand two strokes are completely different animal than four strokes, FAR more finicky, if the mixture is just a wee bit off at certain RPM/throttle you can fry an engine. I know, I've done it MANY times Racing RD's, RZ's and 2S dirt bikes, over thirty years of tuning and riding them. But it's your bike...
 

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Discussion Starter #45
Have considered too rich fuel and eventually too much for spark to handle..... next step is spark test & pull plugs while sitting on the roadside to see if wet, moist or brown馃お
Thank you馃憤 One less thing to track down馃槉
 

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Discussion Starter #46
I hear you, but understand two strokes are completely different animal than four strokes, FAR more finicky, if the mixture is just a wee bit off at certain RPM/throttle you can fry an engine. I know, I've done it MANY times Racing RD's, RZ's and 2S dirt bikes, over thirty years of tuning and riding them. But it's your bike...
馃憤馃槉
 

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Discussion Starter #47
Ok.....got spark on all 3 plugs after 鈥渜uit鈥 mode.... plugs all slightly moist.....so now back to fuel or air? Lines unrestricted, petcock filter clear, ?????

EXACTLY 12 miles on 2separate circuits today....1st trip I THOUGHT it was solved.... loose caps on2 plugs, one so loose it came off in wire, other 1/4鈥 loose馃お

2nd circuit again, EXACTLY 12 miles but timed for my driveway....that鈥檚 when i finally got the spark test done but did NOT drop fuel into cylinders....started on 2 cylinders while 3rd sparked outside....all 3 tested w/ 2 in, 1 out...sluggish but fired... ran sluggish.....
 

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Refresh my memory please. Your bike did not come with electric start, right? So after it quits is it harder to kick than when cold?
 

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Discussion Starter #49
Refresh my memory please. Your bike did not come with electric start, right? So after it quits is it harder to kick than when cold?
Not harder compression, but more difficult to fire.....reacted differently today...see previous post..... usually takes 20-25 minute rest to fire again at good rpms.....
 

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Discussion Starter #50
Not harder compression, but more difficult to fire.....reacted differently today...see previous post..... usually takes 20-25 minute rest to fire again at good rpms.....
And no..... no electric start....kick only
 

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Given that you found loose caps, have you considered getting new leads and caps for all three spark plugs?
Might even consider new coils if the budget allows for it. Plugs are likely moist because the bike was bogging and quit while fuel still being supplied, so I am leaning towards spark being the issue.

Here is a zero-cost test prior to spending $$$. Take the bike out for some plug reading tests. Drive like you normally would and long before it quits, pull in the clutch and immediately hit the kill switch and coast to a stop. Take out at least one plug and have a look. It should not be moist and should be a light brown (tan) colour.

What we are trying to determine is if the bike is running lean or rich, before it starts acting up.

If it were me, I would also do what GPZ550 suggested and install clear fuel lines to all three carbs so you can see what is happening.
 

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Discussion Starter #52
And no..... no electric start....kick only
PERFECT kick start when cold馃槉
Given that you found loose caps, have you considered getting new leads and caps for all three spark plugs?
Might even consider new coils if the budget allows for it. Plugs are likely moist because the bike was bogging and quit while fuel still being supplied, so I am leaning towards spark being the issue.

Here is a zero-cost test prior to spending $$$. Take the bike out for some plug reading tests. Drive like you normally would and long before it quits, pull in the clutch and immediately hit the kill switch and coast to a stop. Take out at least one plug and have a look. It should not be moist and should be a light brown (tan) colour.

What we are trying to determine is if the bike is running lean or rich, before it starts acting up.

If it were me, I would also do what GPZ550 suggested and install clear fuel lines to all three carbs so you can see what is happening.
Interesting.....had spark on all 3 plugs after 鈥渜uit mode鈥, but then again, it started up so i COULD see spark, something it usually won鈥檛 do....I鈥檓 leaning towards lean/rich fuel ... WAS leaning towards spark, but all 3 sparked after 鈥渜uit mode鈥濔煠
and....kinda ruled out rich/lean/air earlier since it鈥檚 only 150 miles out of shop 馃お
 

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Bear in mind that for the first time, it started up right after it quit and the only thing you did different (as far as I know) was tightening the plug caps. Hence, it might be time for new ones, but plug colour test should be done regardless. Yes it is only 150 miles since it was worked on, but did they do a colour test? I doubt it. And in the meantime you could have developed a vacuum leak. Who knows? Colour test will add one more clue to the puzzle.
 

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Discussion Starter #54
Bear in mind that for the first time, it started up right after it quit and the only thing you did different (as far as I know) was tightening the plug caps. Hence, it might be time for new ones, but plug colour test should be done regardless. Yes it is only 150 miles since it was worked on, but did they do a colour test? I doubt it. And in the meantime you could have developed a vacuum leak. Who knows? Colour test will add one more clue to the puzzle.
馃憤馃槉
 

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Discussion Starter #56
Ok....moist is too rich, tan is just right.....too lean is ?
So.......too rich can build up too much fuel to air in the spark chamber.....meaning runs great then bogs eventually w/ too much fuel to air?
 

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Too lean is bone white. Reading plugs is a bit of an art and it has been over-simplified here. Also for most accurate results, the plug should be brand new.

Bikes run best on the lean side but if too lean it will seize the engine. Too rich and performance will suffer and plugs could foul. The other thing we have not talked about is your injector oil and injector pump but lets leave that for another day.

Does your bike have stock exhaust, stock airbox and stock jetting?
 

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Discussion Starter #58
Too lean is bone white. Reading plugs is a bit of an art and it has been over-simplified here. Also for most accurate results, the plug should be brand new.

Bikes run best on the lean side but if too lean it will seize the engine. Too rich and performance will suffer and plugs could foul. The other thing we have not talked about is your injector oil and injector pump but lets leave that for another day.

Does your bike have stock exhaust, stock airbox and stock jetting?
All stock...I鈥檓 too dumb to go any other way 馃榾. Also know center oil pump is iffy.... but I鈥檓 not riding in a cliud of blue smoke馃槉. Very little smoke actually for a 45 yr old 2 stroke
 

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I would do as WFO-KZ suggests. Also you may want to consider the following
Do you understand that all power producing components in your engine are lubricated by the oil pump? The oil that is poured in thru the filler in the clutch cover if for the trans. and clutch only.
You say the center oil pump is iffy. Why do you say that? Are you seeing bubbles in the line? There is only one oil pump, as you sit on the motorcycle it is located under the bulge on the forward portion of the right side engine side cover. The pump works by both throttle position and rpm. The S3 has a single cable at the throttle handle which splits to four under the fuel tank. one for each carb and one for the oil pump. If the cable was ever changed the pump my not be properly adjusted, or the cable could come completely unhooked restricting but not stopping oil delivery due to to the rpm feature. A really well tuned S3 running a good synthetic two stroke oil will produce some smoke on start up, it will produce easily visible smoke on first hard throttle application after warm up, after that they smoke very little. With the injector tank full if you are seeing bubbles in the line I would suggest you remove the oil pump cover. Look at the bottom of the oil pump, you will see one loan screw with a gasket. Back the screw out let some oil flow and then re tighten. This purges air from the tank to pump line. Next start the engine, manually hold the oil pump lever in the full open position, if it is working properly you should see the oil move thru the small engine supply lines in a somewhat jerky flow. Air bubbles should be pushed out with the increased flow.
 

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I am not an expert on two strokes like many of the posters here but I would like to tell you about an issue I had with my ZZR1100 a while ago. The bike would not run properly and would cut out when it got hot. We tested fuel and spark as one does. There was always a spark however it was suggested to me that the spark was not strong enough when the coils heated up. Sure enough I replaced the coils and the problem vanished. I am not saying that this is the issue with your bike, I am just saying that having a visible spark does not mean it is not electrical. Good luck mate.
 
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