I just rebuilt my 87 trail boss 250 removed the oil injection and went to premix
40:1 I set the throttle cable slack set the choke and on the air screw went all the way in and Then came out 1 3/4 it starts up on the first or second pull wouldnt idle so I adjusted the throttle cable while running to get it to idle good but when I go to hit gas it boggs And slowly building rpms and smokes alot and oil was coming out of the exhaust I shut off the fuel valve and would run good and had good throttle response Rite before it died! it leads me to believe I'm running rich what should I do To get it to run rite or what did I do wrong?

 

Did you replace the needle and seat and check the float arm and pin for wear? Could be the problem as 40-1 isn't too much on the oil mixture. Also on an old model like this have the crank seals been replaced? OPT

 

i took the carb apart and cleaned it but i never checked the float and pin i will have to do that! and no i did not replace the crank seals! couldnt i do a leak down test to check it? and the only reason i went to 40:1 is on another forums they said 32:1 was to rich on the oil and they said thin it out a bit! what oil ratio would you use?

 

On an old model like this one I wouldn't even mess with a leak down test and just replace the seals. Seals are cheap,just have to pull the drive clutch and the flywheel. The little 250 piston port engine isn't going to have instant throttle response like a reed valve machine. It may have a little hesitation,but shouldn't fall on it's face! Seals,along with replacing worn carb parts if needed should help. OPT

 

i went out there and checked the floats had nothing on the inside and i fill
the bowl with gas and they went up and floated just fine! the float needle looked fine and the seating surface was fine too! the float arm seem worn from the floats! but everything seems to work good. the only thing i noticed was i
let it warm it up and tried pulled the choke up and it did nothing so that makes me think the chokes not working rite, i set the cable to have 1/8 inch slack i blow through the choke and its clear. one thing i noticed is when i pull the cable off the brass piece is almost the bolt the holds it to the carb.

 

Well I did the test with a vacuum gauge and the float needle wouldn't hold the 5psi like it should
So im going to buy a rebuild kit and hopfully thats my problem! Do you think that could be causing it
Or no?

 

Yes.

 

Ok as a short term fix till I get my carb rebuild kit in. I clean the choke plunger good,
Took a little sand paper to get the biuld up off and I adjusted the float arms and
reinstalled the carb and she running alot better ill keep you guys updated and
Thanks for all the help!