XR250 Dies in 4th & 5th gear

[ButcherToolz]

Hi all,

Thanks advance for you reply

My friend has an XR250 (possibly 86, quite old anyways). However, it rings out fine in 1st, 2nd & 3rd gear but will consisantly konk out in 4th & 5th gear.
This does seems strange as 1st - 3rd are perfectly fine.

Fact.1: The battery is dead but this should not matter?
Fact.2: My friend is quite good with carburettor diagnosis and thinks its not the carby.
Could it be something simple like the coil or sparky??

I was hoping someone may have heard of this issue before.

Thanks again !
ButcherToolz Out.

[Motu]

More likely fuel - check the gas cap breather,fuel tap and float needle,then the jets.

[ButcherToolz]

This would be the first place to start I take?

I'm sure this has been tweaked already.

[Motu]

You start with the easy stuff first,and end up at more tricky stuff later.You don't leave out steps because ''I've aleady checked that'',quite often ''that'' is the problem.Having a sudden burst of inspiration that ''it's the coil!'' is not a sound diagnostic technique.

[White trash]

Buy it a pacemaker.

[Ixion]

Diagnose properly. Don't guess.

Does it REALLY only die in 4th/5th? Or is it just that it dies by the time you get to 4th gear. Can you maintain large throttle opening indefinately in 3rd (use brakes or find a long hill). Does it die if you change up to 4th and DON'T open the throttle, just leave it on the overrun? Does it happen EVERY time -? REALLY every time? Every SINGLE time? Really? You've seen it yourself ?

Have you replaced the plug. Always a first thing to do. Have you drained the carbs and tank, checked tap and fuel filter and replaced with nice new fuel. Have you checked/replaced the airfilter?

Why does your friend think it's not the carb ?

When it dies in 4th , clutch in , wait a few seconds , clutch out (still in 4th) . Does it restart ?.

When it dies, clutch in , stop FAST. Whip plug out, wet? Petrol smell?

Have you tried it with no fuel cap on?

Why do you assume the battery doesn't matter ? If they are mag ignition you may be right - otherwise it very likely does.

[crazyxr250rider]

Hi all,

Thanks advance for you reply

My friend has an XR250 (possibly 86, quite old anyways). However, it rings out fine in 1st, 2nd & 3rd gear but will consisantly konk out in 4th & 5th gear.
This does seems strange as 1st - 3rd are perfectly fine.

Fact.1: The battery is dead but this should not matter?
Fact.2: My friend is quite good with carburettor diagnosis and thinks its not the carby.
Could it be something simple like the coil or sparky??

I was hoping someone may have heard of this issue before.

Thanks again !
ButcherToolz Out.

hmmm my bike did that a bit with the musket exhaust try taking the baffle out (i just put the R model one back on)
also is the choke stuck half on that could do it to

[ButcherToolz]

Thanks all. It did have a tiny air line coming out of the tank so weve stripped that off.

I'm grabbing a new plug tomorrow for my mate. Will check the choke also.

I'll let yaz know the outcome.

[Psyko]

Thanks all. It did have a tiny air line coming out of the tank so weve stripped that off.

I'm grabbing a new plug tomorrow for my mate. Will check the choke also.

I'll let yaz know the outcome.

Another thing to check.......
I had some eratic electrical problems with my bike a while back which turned out to be from approx 1 teaspoon of water in the bottom of the generator housing. Get the revs up and it died! Basically it was arcing thru the water to the engine housings. I took off the left hand side plate of the engine, the generator cover, tiny bit of water trickled out! I dried it all out and put in new gasket! Problem solved!