Subaru engine runs only with choke nearly full on, Mikuni carb

[daved314]

Hello,

I have a Subaru engine which only runs with the choke nearly full on (80-90%). The carburetor is a Mikuni, very similar to the one shown here: http://outdoorpowerinfo.com/repairs/subaru_robin_mikuni_27x-623xx-xx_carb.asp

The site above does a nice job identifying the different parts of the carb for me. I'm new to working on small engines (engines of any size, actually). I've taken the carb off and sprayed with a cleaner which made the carb look much nicer but has not noticeably effected how it performs. I'm thinking of taking it to a small engine shop to have it soaked overnight. I'm posting to ask if it makes any sense to try turning some of or all of the screws to try to improve the performance, before soaking.

I read Sheryle's post "off brand" where a two cleanings, a full disassembly and custom-made gaskets solved a similar problem. I've only seen instruction on removing the float on this carb and am cautious to try disassembling it completely, seeing that replacement carbs are approx. $100 and the engine does run with this one. Not so certain I wouldn't damage something to the point the carb is no longer functional if I set out trying to completely disassemble it (that and I'd rather have a full understanding of what each screw, hole, jet, etc does first).

Thanks for any assistance!

Dave

 

[Mikel1]

If your certain that you have good fuel flow(no blockages in fuel line) to the carb then I would clean the carb. It's not that difficult to do just take your time.

 

[motoman]

I think soaking alone may not be enough if a main jet (present?) or passageway is gummed shut. Sometimes air blast/ soak, airblast/ soak helps. Remember , I"m kinda winging here, but seems like it is also possible on some of the little carbs to remove lead seals to access passageways. (thinking outloud:Was this on a Husqy carb?) The passages are then sealed again with the little lead pellets. Latter is an extreme measure How about probing gently with fine wire. LIke a strand of untwisted small dia cable, or electrical hook-up wire?