Did you check the enrichment adjustment on the mikuni. I want to say that it's one and a half turns from full closed. Make sure yours isn't WAY rich (too many turns out from full in).

 

there is no adjustment on this mikuni carb. the best way is to get the john deere part # for the walbro and buy a new one. it will take some doing to figure the part # the later 12sb ser # will be the walbro carb and the early will be mikuni. if i get time -i might look it up for you . a new one will be your only option. forget about any help from briggs. they quit supporting this engine 20 years ago. its really a japanese engine imported and sold by briggs foe only a few years

 

You're right, Dan..... Zero adjustments on the carb other than one for the idle. I took it off again today and cleaned everything on it and in it with carb cleaner ...Couldn't even get it to pop today.. Spark plug still has a nice big spark and it's getting plenty of fresh fuel so I am stumped.
Dan, when ever you get a chance if you could get me that walbro part # or can point me in the right direction that'd be greatly appreciated! :trink39:
Thanks again.

 

sometimes a mikuni just cant be fixed with a cleaning. i have the briggs "factory" manual for the briggs 2 stroke (quite rare!) and its states the walbro and mikuni are interchanageable but dosnt go further. i have never tried this myself and would hope you dont need any linkage changes. i have both jd 12sb versions and will look into this as it would be a good thing to know . lucky my mikuni version is working fine-but i have had nothing but probs with all 4 past versions of this engine /mikuni. the 12sb when working is an awesume machine. after all a 2 stroke version of the 14sb can only be a good thing! the info for the carb part # is on the john deere parts look up site-but it takes a lot of digging to find as its not very user friendly

 

jd part # lg802619 is walbro carb old part#am108842

 

Awesome! Thank you guys for the suggestions. Looks like I might be picking up the walbro assuming someone has it in stock Thanks for the #'s Dan!
Mike

 

Is there a company on this board or someone that y'all might recommend that might carry this carb ?

 

a john deere dealer is your best bet for this rare carb

 

I am scared to hear how much that will be...:Stop:

 

Thank you sir. I've got a couple close by that I'll try this week. Thanks again.

 

so am i but there is no other way to get one.