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1940 KB triple carb 131 HP

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douglas.bing
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1940 KB triple carb 131 HP

Post by douglas.bing » Tue May 26, 2020 3:49 pm

Help, I'm at 3000 ft elevation, restored 1940 17ft custom, rebuilt KB 131 HP with triple carb, tried both 12x10 and 12x12 prop.
ENGINE RUNS FINE WITHOUT A LOAD ON IT, PUT IT IN GEAR GOES TO ABOUT 18OO-2000 RPM AND BOGS OUT AND DIES.
ADJUSTED CARBS AND MESSED WITH TIMING TILL BLUE IN THE FACE. All I can think of is fuel pump? NEED advice PLEASE.
406-580-4580

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mbigpops
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Re: 1940 KB triple carb 131 HP

Post by mbigpops » Thu May 28, 2020 6:47 pm

With the engine in neutral can you spin the prop by hand ?

Mark
1953 CC Rocket Runabout "Rocket Man"

douglas.bing
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Re: 1940 KB triple carb 131 HP

Post by douglas.bing » Sun Jun 07, 2020 7:04 pm

Mark, yes no problem turning prop in neutral,

douglas.bing
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Re: 1940 KB triple carb 131 HP

Post by douglas.bing » Tue Jun 16, 2020 10:29 am

Any chance someone might have some advice on things to check/Troubleshoot?
and the correct prop size?

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drrot
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Re: 1940 KB triple carb 131 HP

Post by drrot » Tue Jun 16, 2020 12:35 pm

12 1/2X13 propeller. You should get way more RPM with either propeller you have. I'd start with synchronizing them by hand and make sure all carbs Fully close and fully open evenly. (not running) then adjust the idle mixtures then idle speed. Finally take it out with two people and adjust the high speed. If you are not getting anywhere run it for a bit then check the plugs. If a pair of them have bad color go through that carb again.
Jim Staib
www.finewoodboats.com


1947 Penn Yan 12' Cartopper WXH474611
1950 Chris-Craft 22' Sportsman U-22-1532
1957 Chris-Craft 26' Sea Skiff SK-26-515
1968 Century 17' Resorter FG-68-174

douglas.bing
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Re: 1940 KB triple carb 131 HP

Post by douglas.bing » Mon Jun 22, 2020 9:06 am

Thanks for the tunning procedure!Jim , Will try it, no thoughts on fuel pump, it is newly rebuilt, any way to test it ?
Mechanics never my thing

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drrot
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Re: 1940 KB triple carb 131 HP

Post by drrot » Mon Jun 22, 2020 12:12 pm

The quick way to test the fuel pump is remove the line from the tank. Put your thumb over the fitting on the pump. Actuate the lever on the pump and it should suck you thumb in.
Proper way is to insert a vacuum gauge in the pump.
Jim Staib
www.finewoodboats.com


1947 Penn Yan 12' Cartopper WXH474611
1950 Chris-Craft 22' Sportsman U-22-1532
1957 Chris-Craft 26' Sea Skiff SK-26-515
1968 Century 17' Resorter FG-68-174

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