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R50/2 149-150 Carbs fouling plugs, put 105's in and seems fine...but is it?

Daves79x
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Location: Knox, PA. USA
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Re: R50/2 149-150 Carbs fouling plugs, put 105's in and seems fine...but is it?

Post by Daves79x »

I have found that for carbs of unknown history and mileage, it's best to research the stock jets and settings, replace main and pilot jets, jet needles and needle jets, mixture screws and floats and float needles. Obviously, a complete cleaning of the carb bodies is necessary. Set the mixture screws to the recommended setting to start, then fine tune from there. At least then you'll know any further problems are far less likely to be the carbs.

Dave
Dave

Thunderdome74
Posts: 19
Joined: Sun Dec 26, 2021 2:59 am

Re: R50/2 149-150 Carbs fouling plugs, put 105's in and seems fine...but is it?

Post by Thunderdome74 »

Thanks Dave

The floats seem to be ok, I had them floating in a container of fuel for a week and no leaks(one did but i patched it with solderlene, still 7grams)

I have 2 sets of carbs(one for the finished R50/2 the others are for the R60, in the process of being built,) One carb had the lever top ,i have bought another lever top, so one set will be lever top and the other ,the long float needle type.

I will be replacing all 4 of the carbs needle jets, min jets and the pilot jets.

The carbs all have the identical numbers,149-150, so will be fitting them with 120's as the 120's i have are bigger afaik(caused the fouling)

The 105's i have drilled to 1.15 are temporary, but in doing so i have a ridable bike , so it is definitely a leading cause of the plug fouling


Guys , thanks again for the help...getting there

808Airhead
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Re: R50/2 149-150 Carbs fouling plugs, put 105's in and seems fine...but is it?

Post by 808Airhead »

You need to play with needle positions or possibly idle jet. I live near sea level and I SLIGHTLY enlarged my idle jets for better low RPM transition and that helped my R60/2. These bikes like t run rich,but not so much you are washing cylinders and fouling plugs. Make sure your compression and valve seat seal are GOOD, or the carbs will never respond correctly. You can try with the stock jets and lifting the needle slightly in slide and see how responsiveness is. Remember that a bike with low compression/or that burns oil NEEDS a richer mixture to run,so mechanical condition has a LOT to do with carb function. Low compression also equals low vacuum......
Thomas M.
R69S - R60/2 - R67/2 - R51/3 - R69

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