Hello,I have a 1986 polaris 250 which has now had every frigen part replaced,its a brand new 23 year old quad that I have gotten about 6 hours of ride time on.My hopeless quest of trail riding fun began when I bought this quad from a neighbor,it ran awesome,took it to the trails and it ran great allday,then I lost throttle.At half throttle it tops out and boggs down.I noticed it was flooding,had issues due to its age,so I took it to a local polaris dealer in annville pa for a rebuild and they didnt empty my crankcase and blew out my seals,didnt fix the carb and also took my skid plate off and said it wasnt on when I brought it in,so then I replaced the seals and skid plate,while I was at it I replaced every gasket and seal on the whole motor.While doing this I noticed my rings were bad so I replaced them,but this still didnt fix my problem!! Next I went to electrical,I replaced the CDI,coil,regulator,rev limitor,starter,cilinoid,battery and cables,This still didnt fix my problem.Then I ripped all the wiring out and redid everything,new shrinkwrap tubing on the wires and harnesses,cleaned off any corrosion or rust on all the connections.After all this the same problem still exsists!!!!! Ive had the carb out 30 times and still nothing.It will start right up on the starter or on one pull and sometimes hold an idle but when you get about half throttle it stops excelerating and boggs down.I have plenty of compression and spark,im about ready to give up.If theres anyone who can help or has any ideas,please let me know,Id appreciate it,Thanks.

 

Check rubber boots from the carb to the motor.......Sounds like air is getting in there instead of fuel!!..................Caper..........

 

From what I gather from your post you said you replaced rings. Did you check piston clearance ( if more than .004 rings could be temporary fix) New rings on a worn piston will usually eat up rings faster,plus start to loose compression when warm. Just a thought!

 

is this in neutral that it dies out half throttle? just wondering(cant remember if it does) does this have a vacume fuel pump that is maybe bad and starving it for gas? hows the plug look,wet,black? if it was bogging out in gear maybe i would say check the clutches? just a couple of idears.

 

86 just gravity feed from petcock.

 

I put a new belt on and checked the clutch and driven pulley and there fine,about the only area I didnt check is inside the tranny,only because it was running great until the flooding problem occured and didnt think there was a problem with it,But after all this it wouldnt surprise me.The carb boots were also replaced so I know theres no holes but I will double check to make sure there is a good seal.Im also going to try disconecting the oil pump and mixing the gas.Ive had the hose off to the jug and oil is coming through,but I dont know how fast its supposed to pump,if its just a trickle or alot?If this dosnt work than Im going into the tranny but when I have it in neutral it boggs down the same as if I had it in gear. Thanks everybody for the brainstorm,I will be applying all your suggestions tomorrow and let you know how I make out.I may be calling on everyone again for some more ideas if these things dont remedy the problem.Thanks Again!!!!!!

 

while it is running spray wd 40 on the boot feeding the carb if it is leaking the engine will rev up if so replace intake boot hope this helps ya

 

P.S.... The fuel is gravity fed directly into the carb,and the plug looks fine,no wetness,but also no blackening from oil,This is why I might bypass the oil pump.Thanks.

 

Did the early polarises have ETC and or rev limiters? Doc

 

The 86s have a voltage regulator,rev limiter,(two small black boxes)CDI and a coil.I dont know how the rev limiter acts as its going bad,wheather or not it slowly goes bad or if it works or dont work? The one I have on it now is a used one from another 86, the quad it came from ran fine,it had a broken frame so It was parted out.