# 4HP Subaru Robin Carb Issues



## Pomfish

I just got a Baja mini bike with a 4hp Subaru Robin engine and she fires right up on choke and will run from about 1/2 throttle on up to full fine with choke off, but bogs below that and will not idle.
Spark Plug looks very clean.

It seems like the idle/slow speed carb circuit is not functioning.
The carb is labeled mukini, the motor seems like a clone engine but says made in japan, not china.
Still looks like honda clone to me.

Just wondering where to look in carb. 
I have had the bowl off and every thing there is clean, main jet is clear.
Plan on tearing it off engine tomorrow, just looking for some help.

Thanks,
Keith


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## 30yearTech

The carburetor probably has a removable nozzle and pilot jet. You will need to remove the carburetor to get down inside it and remove these for proper cleaning. It does sound like your low speed circuit is dirty.


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## usmcgrunt

I don't know if this is your carb or not,but it may help you.

http://outdoorpowerinfo.com/repairs/subaru_robin_mikuni_27x-623xx-xx_carb.asp


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## Pomfish

Well, I pulled the carb today and am now convinced that the gaskets on each side of the plastic spacer are the problem.
The one at the block was torn bad and the other is very worn/thin looking.
I ordered both gaskets today, they will be here early next week.
I will update then.
Thanks for all the help and info. Looking at the close up views of the carb even while not exactly like mine it was close enough and when I got it off I knew what to do.

These Robin motors seem decent.
Thanks,
Keith


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## Pomfish

She runs perfect with the new gaskets. 
Remounting the carb was a treat as they don't have any slack in the fuel line and getting it back over the mounting pipe was a nightmare.

Anyway this Robin engine starts on one pull and just purrs, wish I could get a Briggs to idle that nice and run that smooth.
Thanks all for the help,

Keith


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