Kawi2strokes.com Forum

My 1969 500 h1 has recently rebuilt carbs. It starts easily, 1 or 2 kicks with the enrichment lever is depressed. I can't let the lever go until the bike is warm or it will stall. Once warm the engine idles fine and from 2500 up pulls just fine but between idle and 2500 the engine stumbles badly. Any thoughts. Could the enrichment circuit not be fully closing.

Did you use carb rebuild kits? They all contain improper jets.

Welcome to the board, bodhi1601!

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If it surges, that's normal, upshift.

Are the carbs synced properly…

Idle and slide,, choke cables should have slack and be routed properly to carbs ,, different lengths…

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1977 KH 400
1976 KH 250/350 rat bike
1971 KV 75
1976 KV 75

The carbs were professionally rebuilt by the previous owner. The engine accelerated smoothly when I first got it but has deteriorated over the last year. Moving off from an idle is now difficult because of the engine stumble. I geberaly have to rev up to 2500 to 3000 and slip the clutch to avoid stalling. Could it be the enrichment system. I have slacked off the cables. They don't seem to be binding. How can I tell if the plungers are fully closed when the engine is warm and the lever is not depressed?

Your symptoms indicate too lean a mixture. That is often clogged jets, but you didn't answer my question about whether carb rebuild kits were used. If so, that's probably the problem. If you take a close look at the pilot jets, the needle jet, and the main jet, you can see if they have the Mikuni logo on them. Carb kits use non-Mikuni jets.

Unfortunately, professionals don't always do the right thing for triples.

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If it surges, that's normal, upshift.

Thanks for the comments and help. Last week I got a chance to work on the bike. I was ready to pull the carbs and check the jets but I tried something simple first. I slacked off the enrichment lever cable adjuster at the handlebar and the worked the cable in and out a dozen times wiggling the plunger attachment at each carb. I tried to feel each one snapping shut. I'm not sure if I could feel them closing but afterward the bike started first kick and ran flawlessly. I don't know if the enrichment cable was the problem or if tapping the carbs knocked something loose in a jet that was otherwise causing a lean condition but the problem seems to be solved. For now anyway.

Well, if tapping on them knocked something loose in a jet, it would be wise to take the carbs off and clean them well, because that's not the only piece of dirt in there. Also it would make sense to use some inline pleated paper filters if you don't already have them.

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If it surges, that's normal, upshift.

Sounds like the liquid levels (float levels) are too low.

Sure sounds like a plunger was hanging up …

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1977 KH 400
1976 KH 250/350 rat bike
1971 KV 75
1976 KV 75