# Frequent battle with Toro 20622 and Mikuni carb.



## ls3c6 (Aug 4, 2011)

Every few months I have to remove the carb, removing the needle/float/main jet. I clean the pinhole in the main jet, the holes in the pilot jet and reassemble.

This usually fixes a problem of running lean and bogging/knocking with a medium load.

I just did it again yesterday and while I was able to cut the lawn it seemed to be down a bit on power.

Any suggestions? 

Here is a link to a breakdown of the carb: http://i883.photobucket.com/albums/ac31/bwolfy53/Mower/3_554019.gif

I don't recall seeing this #20 tube in mine


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## usmcgrunt (Sep 16, 2007)

Hello.Here is a link to cleaning a Mikuni carb.If you have to clean the carb frequently,you may have dirt inside the fuel tank and it should be flushed out.It would probably be a good idea to also put a filter in the gas line. Hope this helps.

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


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## ls3c6 (Aug 4, 2011)

usmcgrunt said:


> Hello.Here is a link to cleaning a Mikuni carb.If you have to clean the carb frequently,you may have dirt inside the fuel tank and it should be flushed out.It would probably be a good idea to also put a filter in the gas line. Hope this helps.
> 
> http://outdoorpowerinfo.com/repairs/subaru_robin_mikuni_27x-623xx-xx_carb.asp


Oh I see! I haven't removed/cleaned the emulsion tube ever... maybe I should? It does have a fuel filter but i'll get new line and filter, I already drained the tank


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## ls3c6 (Aug 4, 2011)

I again disassembled the carb and checked everything including the main nozzle, I couldn't remove it but it didn't appear blocked in any way. I replaced the fuel lines and fuel filter because they were disintergrating so I would always get a lot of black speckles in the fuel filter and in the bowl of the carb.

I set the RPM to 3500 with the blade engaged. I noticed once the engine was warm and I put the throttle back into the choke position (closes butterfly at inlet of carb) the RPM would drop to 1500... is this normal behavior? Usually when I start it in the choke position it revs much higher.

One other thing, when I add oil to the engine getting the level to the middle/top of the operating range it burns oil off when I start it... it just doesn't like having more oil than just above the lower line of operating range?

I haven't mowed again with it yet, but I did remove the plug after running it 3500rpm with blade engaged and the plug was to the whiter side of tan... but not lean/white. This mower was made in 1988 back before we were forced to use fuel containing 10% ethanol... should the jet be at all modified because of this to richen the mixture?


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