Kawi2strokes.com Forum

Hi All!

I have totally rebuilt a 1975 H1 and can't get it to run right. Around the neighborhood is OK but not on the highway.
It surges and slows down and won't take throttle at 4-5K in top gear. When I stop the left plug is wet and the others are brown or black but dry. The float height in the rebuilt carbs is set at 25mm, there is plenty of free play in the enrichener cables, but the rubber seal at the bottom of the brass enrichener plug has a circle worn into it.

It acts like it is starving for fuel but the plugs say otherwise.

What am I missing?

Tim Castellano

also I installed a brass clutch actuator (from Germany I believe) and now matter how I adjust it either the clutch won't fully disengage or it slips. The pull is way lighter however!

The wet left plug could indicate that the L cylinder is not firing. Does its head pipe get hot like the others?

Did you use jets in carb rebuild kits? If so, you need to put the genuine Mikuni jets back in.

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If it surges, that's normal, upshift.

Switch the carb to another cylinder and see if the problem follows..

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

Good idea Johnny, but I've been waiting a week to hear if he used a carb rebuild kit. I think he's AWOL.

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If it surges, that's normal, upshift.

Hi fellow triple lovers!

Sorry for being AWOL. Spending my time working on the bike rather than online this week. I have replaced all the carb parts form the "Sudco" rebuild kits with NOS Mikuni parts after testing the float valves. All 3 leaked like a sieve. Therefore the jets are also suspect in my view.
Sudco says there could be counterfeit rebuild kits out there with their name on them!

Still waiting on original spec enrichener plungers, needles and airscrews, but so far it hasn't improved.

I also found 2 of the carbs have oval shaped float pivot pin mounting holes (in the carb body itself). Could this cause the rich condition?

I have the needles that came out of the bike but they are labeled 5EI4 (as compared to stock 5DJ19). Next I will try swapping those and the original air screws and new enrichener plungers.

Sign me
Clueless in California

Hi Everyone,

Pretty sure my problem is solved. My carb bodies had ovalled holes where the float pivot pins go in. Replacement carbs from Ivan's and one of his jet kits with genuine Mikuni float needle jets and seats seem to have done it. Also the float needle seats leaked between seats and carb body unless assembled very carefully. All carb passages verified clean.

Sudco rebuild kits tossed, the needles were the wrong shape and all 3 were different from each other! Float needle valves leaked horribly and who knows if the jets were the right sizes!

Bike now runs much better and pulls strongly. Plugs light tan and uniform (as opposed to black and wet) and all three header pipes equal temperatures.

Has anyone seen carb bodies worn in this way? I never have and I have restored a bunch of 1970's bikes with Mikuni carbs.

Tim

Thanks for the update, Tim. That's another example of jet kits adding to existing problems. Enjoy the H1!

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If it surges, that's normal, upshift.

An update on my 75 H1 that was fouling plugs. It is solved! New old carbs from Ivan's and his jet kit solved it. Runs really sweet now. Starts second kick, idles beautifully and pulls strong up through the gears. The shifting was also solved by carefully assembling the clutch with all the plates is the right orientation and super careful clutch actuator adjustment. Thanks to those board members who posted instructions on how to do this right (and Ivan).

I was frustrated by this bike and began to doubt my mechanical ability and sanity but I learned a lot and the next one (yes I have another one!) will be done right the first time. You may be right, I may be crazy....

I almost forgot how much fun to ride these things are!

No longer clueless in California

Tim

Hey Tim...just stumbled across this thread. Good to hear you got it.

I too had issues when rebuilding my H1 several years ago. The "Sudco" carb kits I bought from a well known venor on the E Coast had bad jets, once replaced with genuine brass, the bike has run good ever since. Rode it last week, what a blast!!

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H2B..... H1E..... Z1B ..... RD350...... X6 Hustler..... TS250.... CB750 ..... CB550...... and a Bomber!!