89 250r bog

[dtr250r]

ok, so i just picked up this 89 250r, and its got lots of work done to it, im not to sure about thats done to the motor tho, it could be ported polished....etc...but i got it running amazing last night, and this morning i started it after 2 kicks, but its bogging when i give it gas, about 2 out of 3 times i i hit the throttle it bogs then revs...any ideas whats wrong? here is the atv with all the plastics off..needs the frame painted... http://s1184.photobucket.com/albums/z333/dtr7720/trx250r/

[Grande Huevos]

If your sure its not a jetting issue or dirty carb it could be something electrical maybe the coil? But it could be a cracked reed. I had a bike with a cracked reed and had similar symptoms

[dtr250r]

Originally posted by Grande Huevos
If your sure its not a jetting issue or dirty carb it could be something electrical maybe the coil? But it could be a cracked reed. I had a bike with a cracked reed and had similar symptoms
i looked at the reeds last night, they appeard to be in amazing shape, as far as i could see they werent cracked, chipped, falling apart(my kx 250 reeds fell apart). it could be jetting, i will go look and see what jets re in it later tonight. i beleive its 170? main, 55 pilot, and the needle is in the 2nd position

[Grande Huevos]

what size is your motor?? if you can give some more details on the parts your bike has like bore size, port work, reeds, carb size ect... it could help us help you better. If its a stock 265 then i would say you are prob to fat. I would start by moving your needle to the middle clip position and while your in there write down the letters or numbers on the needle so you can find what needle you have. a 170 main is prob a lil steep thats about what i ran in my built 310. Also check the wire in the cap that snaps onto the spark plug because if its corroded or somtimes burnt off this can be very crucial in how your bike fires/runs

[dtr250r]

Originally posted by Grande Huevos
what size is your motor?? if you can give some more details on the parts your bike has like bore size, port work, reeds, carb size ect... it could help us help you better. If its a stock 265 then i would say you are prob to fat. I would start by moving your needle to the middle clip position and while your in there write down the letters or numbers on the needle so you can find what needle you have. a 170 main is prob a lil steep thats about what i ran in my built 310. Also check the wire in the cap that snaps onto the spark plug because if its corroded or somtimes burnt off this can be very crucial in how your bike fires/runs

it has a 172 main, 60 pilot, its suppose to be a 270, im not sure what all is done inside the motor, havent had it apart, but it wil be apart this winter, the whole thing is getting restored

[dtr250r]

and the reeds could be stock, im not great with this stuff. il have my friend look at it

[Grande Huevos]

Im going to assume your carb is an aftermarket prob a kehin??? If so your running a stock cylinder with a 172 main and 60 piolet........from my experience this sounds incredibally fat. I would def drop your piolet to a 48-50 and see what happens. I would also start dropping the main down in increments im guessing you will end up somwhere around a 152-160. While you have your carb opened up you might spray some carb cleaner all over and make sure u get in all the holes cracks and crevises just to make sure its free of build up and dirt particals. Keep us updated with what you find out.

[Langbolt]

Looks like a Stock Carb.....Is the CHOKE on ?

How much fuel is in the tank ?

Is it fresh ?

Are you using the same OIL that the previous owner used ?

What Fuel:Oil ratio ?

Do you have the fuel valve to ON or RESERVE ?

Let us know

:devil:

[dtr250r]

ive already cleaned the carb, about 7 times, i just had my friends dad clean it and tune it, the cylinder is a 270 which appears to be ported and polished

[k7mm]

I hate telling people this,but it could have an airleak.Since you cleaned the carb 7 times and if you've changed your jetting to try and fix with no good results,then it is possible you have an airleak.Under a load it will bog or lose power?Bad head gasket possibly?The craziest airleak culprit is the crank seal behind the stator.Why I do not know why that seal goes out,but if you can not find the problem,just know that,that seal does go out and the engine will suck air under a load.
Keith

[dtr250r]

if there is an air leak on the crank seal, would there be oil around the stator

[k7mm]

Originally posted by dtr250r
if there is an air leak on the crank seal, would there be oil around the stator It is a good possibility that there would be oil in there.Depending on how bad it is,it would be sucking air,not spitting fuel/oil mix.Cleaning the carb is one thing,having the jetting right is another.Here is a link to Kehin jetting from Duncan.
http://www.duncanracing.com/TechCenter/Carburators.phtml
If you have an airleak,it will only be noticable under a heavy load,bogging/cutting out on full throttle.

[dtr250r]

well there is zero oil around the stator, but when i give it gas, it goes bog...and if i tigve it gas slowly it will rev sometimes

[dtr250r]

ok, so i just went through the elctronics, there all good