bypassing oil pump on 2 stroke atv good or bad

robertcwilkins · #1 (**permalink**) 03-10-2011, 05:20 PM

I recently purchased a 1987 Trail boss 250 4x4 2-stroke in rough condition. I am attempting to redo everything on it and came across a problem. At first when i press throttle completely down it would smoke really really really bad and die out. So I adjusted the linkage for the oil pump to lean it out. Now i still press the throttle down a little farther but and it still dies out. So do i need to adjust the throttle side of the cable more to limit the fuel or the screw one the side of the carb? Im kinda at a loss with it cause its two stroke and oil injected. So long as i dont go full throttle its ok. Course it wont stay idling unless i keep it pushed. Any sugguestions? For me its different because when i rejetting my other atv i had some general guide lines, ie, 1.5 turn out one screw etc.

**Bruce!** · #2 (**permalink**) 03-10-2011, 06:17 PM

Welcome to the board!

dirtywhiteboy · #3 (**permalink**) 03-10-2011, 09:18 PM

not that i have a clue bout atv carbs but you may find some info here...
Common Carb Issues

robertcwilkins · #4 (**permalink**) 03-11-2011, 04:44 AM

Thanks for that link that answers some of the questions, I just need to experiment more with it now.

curtiscapk · #5 (**permalink**) 03-11-2011, 05:41 AM

Robert,
Nice lookin 87..

I think it is all in your carb. Take it apart and use speaker wire to clean out all jets and ports. It took three times to get mine to quite doing the exact same thing.

mhollerich · #6 (**permalink**) 03-11-2011, 06:15 AM

yes clean the shit outta the carb...check the airbox..new air filter new plug... make sure the boot between the cylinder and the carb is not cracked(a crack will cause it to run like shit) new gas if not already and put the oil injection back to the way it was....(if it was original, theres no reason to mess with that...) try and find what factory adjustment is and put it there

robertcwilkins · #7 (**permalink**) 03-11-2011, 06:36 AM

Only other problem i have with it is the starter is frozen up. I bypassed the solienold and starter still wont turn over. I attempted to remove it but it appears that i have to remove alot just to get the bolts off the starter housing. It pull cranks fine after about five or six pulls. Also Im confused on the choke. I have a cable with a lever that appears to be choke. Its right nxt to key. If i pull the lever back during engine running it kills engine. So i never touch it. Is that the choke? Should it crank with it pulled then put it back to normal when idling? It will not crank if is pulled back. I dunno.

dirtywhiteboy · #8 (**permalink**) 03-11-2011, 09:37 AM

Quote:

Originally Posted by robertcwilkins

Only other problem i have with it is the starter is frozen up. I bypassed the solienold and starter still wont turn over. I attempted to remove it but it appears that i have to remove alot just to get the bolts off the starter housing. It pull cranks fine after about five or six pulls. Also Im confused on the choke. I have a cable with a lever that appears to be choke. Its right nxt to key. If i pull the lever back during engine running it kills engine. So i never touch it. Is that the choke? Should it crank with it pulled then put it back to normal when idling? It will not crank if is pulled back. I dunno.

yes,thats the choke,...an sound like its workin too!

robertcwilkins · #9 (**permalink**) 03-13-2011, 05:21 PM

Well I got it all figured out today, I adjusted the screw back to 2.5 and works like a champ now. Now i took the starter to realize that it needs to be rebuilt, all brushes are broke, thus making it now work. Just too bad that i had to remove clutch to get to starter. On top of this my pull recoil rope broke having to replace that too.