Mikuni Carburetor (Subaru Part 279-62361-00) on an Subaru EX27 Engine

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pstrickey

Member
I have a Dewalt Pressure Washer (DS3532) with a Subaru EX270D503618590 Engine with a Mikuni Carburetor (Foam type) that was surging so I disassembled the carburetor and cleaned it. After I reinstalled the carburetor it was still surging so I did some more research (this forum is great with a wealth of information!) and looked at youtube videos. I have two questions:
* The main jet (correct term??) in the tube that is normally unscrewed to remove the jet and then able to clean the tiny holes on the side appears to be pressed into place and cannot be removed. I have not been able to find out if this tube should be removed to clean further, or not. Any thoughts?
* The pilot jet I removed and cleaned the side & top holes but I could not tell if there should be a tiny hole at the bottom of the pilot jet to clean. If there is supposed to be a tiny hole here mine is clogged and I have soaked it in a sonic cleaner but still not able to find a hole. Any thoughts?
Pictures are below and hopefully this will help more than my misidentifications!

Thanks again for your help!
Paul
 

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you can use a light to shine thru jets to see if they are open. Also - is the carb filter clean? How about, new fuel?
 
All jets I could get to are clear with no obstructions. All gas was drained out of the gas tank and the fuel line & filter were replaced. Only 100% gasoline with stabil was used. On the pilot jet, I cannot tell if there is a hole in the bottom of the jet, or not (as shown in the picture). Obviously if this was clogged it would account for the engine surging? I know aftermarket carburetors that fit a Subaru EX27, the pilot jet does have a hole at the bottom, but don’t know about the original Subaru carburetor and its pilot jet. Thanks for all of the comments & suggestions so far. Hopefully someone will know about the pilot jet ”hole” question.
 
pstrickey said:
All jets I could get to are clear with no obstructions. All gas was drained out of the gas tank and the fuel line & filter were replaced. Only 100% gasoline with stabil was used. On the pilot jet, I cannot tell if there is a hole in the bottom of the jet, or not (as shown in the picture). Obviously if this was clogged it would account for the engine surging? I know aftermarket carburetors that fit a Subaru EX27, the pilot jet does have a hole at the bottom, but don’t know about the original Subaru carburetor and its pilot jet. Thanks for all of the comments & suggestions so far. Hopefully someone will know about the pilot jet ”hole” question.
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There is a hole in the bottom that will connect with the holes in the side of the jet.
 
Ilengine: Thank you for that information about the hole should be in the bottom of the pilot jet. Any suggestions on how to get it back opened? I have tried probing with a carburetor jet cleaning rod/brush and a small pointed pick after soaking for hours in carburetor cleaner (even in a sonic cleaner) with no luck. At least this now explains why the engine is still surging! Thanks
 
pstrickey said:
Ilengine: Thank you for that information about the hole should be in the bottom of the pilot jet. Any suggestions on how to get it back opened? I have tried probing with a carburetor jet cleaning rod/brush and a small pointed pick after soaking for hours in carburetor cleaner (even in a sonic cleaner) with no luck. At least this now explains why the engine is still surging! Thanks
Click to expand...
Those holes in pilot jets can be really small sometimes. Sometimes a single wire from a hand wire brush is small enough to go into the hole. Other times I have had to use a single strand from electric wire. but have to be careful about using soft wire that it doesn't break off inside the hole.
 
the hole may only be open to the depth of the two side holes. How far does a small paper clip etc., go in? Using something that is metal is not desired because it can change the side of the hole but sometimes ya gotta do what ya gotta do.
 
Thanks everyone for their help! At least now I know the pilot jet is clogged at the end and will try some more to find the opening, including using a single wire from a wire brush (or anything smaller).

Thanks again! Paul
 
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