85' 250sx won't run right

[Bojangles]

Alright so I bought this beast from a friend,I remember It use to run great,until it got bogged out in the sand dunes! He mentioned that it wasn't running right before they got it stuck, that it would just die out after driving it for 15-20 minutes. Once I got it home I drained and flushed and replaced all fluids (rear end,oil,gas). Then changed the plug and bought a new coil pack. She fired over and ran fine. So I took er out for a good rip and it died out just like he said after 20 minutes or so. It wouldn't start right away but it seamed like it flooded it self,finally half hour later she fired up and I drove the piss out of er for a good 2hours without any problems. So a week later i take er out for a rip and the same thing Happened she quit once I slowed down to almost idling. Only this time it would Start right up and die every Kick or Idle for 5 Seconds then quit. So I took the carb apart and cleaned it out everything looked good except the main jet baffle,looks a little worn where the overflow tube sit against would that be Causing it to flood out or run too lean?, or does it sound like something's overheating? Please help!!

[chargercharlie]

Ive ran my aftermarket carb with no baffle with no issues..sounds like you may just have missed something in the carb.
Sometimes it takes a few times to get all the crud out
.buy some carb dip and let it sit for a while..when done make sure to blow your jets out with compressed air..make sure your float needle valve is not sticking and measure the float height and if need so adjust to specs..make sure everything is super clean before putting back together..

[Bojangles]

I don't believe the float height is adjustable on that carb but I will clean it out again

[shortline10]

Check your gas flow , could be a dirty petcock or gas cap not venting correctly .

[Bojangles]

Also the choke is a little hard to move open and close but when I took it out of the carb it seamed like it was working right

[Bojangles]

Fuel is flowing good, how can I check the cap?

[chargercharlie]

Take your cap off and run the bike if it doesnt do it there ya go if it does its not the cap vent..Be careful not to spill fuel of course.

[cap]

The fuel cap can be pulled apart to clean the vent holes and realign the tabs that open it up. Search youtube for a video on how to do it, basically its just pressed together one inside the other, it can be pried apart.
I had one that would die after 5-10min of riding unless I set the fuel vent lever halfway between on/off, that was just enough to make the vent open up. The tabs inside were bent down from dropping the cap.

[Bojangles]

200000 is this my problem?

[Bojangles]

The other side looks straight and not slanted like this one

[chargercharlie]

Not quite sure whats going on in that picture..Do you have a manual for your model bike? Did you run your bike without the fuel cap to see if the issue resolved?Did you clean your carb again?

[Bojangles]

The fuel cap can be pulled apart to clean the vent holes and realign the tabs that open it up. Search youtube for a video on how to do it, basically its just pressed together one inside the other, it can be pried apart.
I had one that would die after 5-10min of riding unless I set the fuel vent lever halfway between on/off, that was just enough to make the vent open up. The tabs inside were bent down from dropping the cap.

I guess it's not the problem!! It was just running great until I clipped the seat on and she died

[Bojangles]

Wait!!!!!!

[Flyingw]

Did you find anything? Sounds like a wiring issue.

[danbur55]

Is there a tether kill switch back there??

[Bojangles]

I think it is the gas cap, I'll get a
New one and hit the trails for a good run

[Bojangles]

I'm still thinking it's something else tho!

[Bojangles]

Is there a tether kill switch back there??

I don't think so, it was just a coincidence that it died when I put the seat on!

[Bojangles]

It's still acting up! With the fuel cap off, I thought that was it but same thing it just peacefully dies after about 15 minutes of idling with the odd rev. Then it's a trailprotrailprotrailprotrailprotrailpro to start again. I can shut it off and start it up no problem until it stalls once and it's done I have to kick her over a bunch just to get er going

[Bojangles]

I cleaned the carb pretty good the first time but mabey another cleaning is due! What would I check for electrical? It had a weak spark from the old coil pack but I replaced it.

[atc007]

When it dies. Immediately loosen your drain bolt on your carb. See if it's full of gas. It's sounding like a bad coil. But eliminate fuel 1st.

[Bojangles]

I ordered a new cap from honda $80, I should get it in a day or so

[Bojangles]

A friend mentioned a while ago he thought it was a bad coil!, wouldn't that be the coil
Pack tho? I replaced that.

[atc007]

Diagnosing these is actually a pretty simple,step by step process. Throwing parts at them can be very frustrating and expensive to say the least lol . Any coil on it's way out will generally start to die with increased heat. You have a stator which creates your spark before handing it over to the coil with the spark plug at the end. These are all tested with an ohm meter,and resistance readings ,found free on the internet through service manuals. Cracking your drain screw on your carb after it dies would have instantly told you yes or no. If it is starving for fuel. Riding it without the cap,which I think you said you did,and it still died. Verifies your cap is good. FlyingW,did a post on a thread about a 250ES Big red,same ignition as yours. That should be a how to at Every single tech school. His simple to understand,understanding of electronics is scary at best. I can do it all. But I damn sure would never race him. Because I would lose! If you can find his post. It will explain very simply how your ignition works. Good luck.!

[cap]

I ordered a new cap from honda $80, I should get it in a day or so

80$$! I thought the cap was OK?

The TRX cap is the replacement from Honda.

39$ here.
http://www.ebay.com/itm/GENUINE-HONDA-GAS-FUEL-CAP-TRX125-TRX200-TRX250-TRX300-17620-HC3-505-/221521615786?pt=Motorcycles_Parts_Accessories&hash=item3393b79baa&vxp=mtr

[Bojangles]

It needs a cap anyways the old one is all beat up!

[Bojangles]

Well folks she still quit and as I opened the drain plug on the carb.......
Fuel everywhere!!!

[Bojangles]

Well folks she still quit and as I opened the drain plug on the carb.......
Fuel everywhere!!!

[Bojangles]

FlyingW help!!

[85triz-250]

Check spark immediately after it dies. Its sounding like a spark issue to me

[dixietoolz]

I had a similiar issue at one time. Would run great for 5 minutes then bog down and cut off. Sit for a few minutes and fire right up. Ended up being when I had cleaned the carb I had bent the tabs which control the float valve. Took it to a buddy who is a carb genius and after a few adjustments back to stock it runs great.

[Bojangles]

No that's not the problem we've eliminated everything down to electrical. And maybe the killswitch not working could be playing a part in it? Bringing out the ohmmeter!