XR250 Flooding ?

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#1
My buddy has an 84 XR250R that I had borrowed. It was in need
of some TLC but did start second kick everytime. Once started it ran OK but did hesitaite, etc. So to do him a favor ? I cleaned the VERY dirty K&N Air Filter and replaced the old worn plug amungst other things. The bike runs way better but now, but it is hard to start ? It seems to flood everytime it turns off and to get it going you need to shut the gas off and kick it with the throtle open several times to fire. It has the dual carb config.

Any ideas on why this is happening ?

Thanks !

2 Stroke Guy
 
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#2
One or both of the carbs probably has float level set way to high or more likely a leaky needle/seat that can't shut off the fuel flow.

Small bits of crud can keep the fuel valve (needle) in the carb from seating cleanly on it's seat.

An easy place to start is to run the carbs dry and blow through the fuel line to try an dislodge and junk on the fuel shut off. If that doesn't work the carbs will probably have to come apart for a good cleaning.
 
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#3
Thanks !

I have done a lot of work on single carb 2 smokes (getting, adjusting, etc.)

The 2 carb thing scares me since it's not my bike. My first thought was that something is floating around causing grief. Is their any problems with the carbs needing to be set exactly the same ? How is the idle adjusted ? It does produce a lot of black carbon in the SuperTrap that I also cleaned but it never fouls plugs.
 
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#4
If the needle & seat are consistently leaking it will always run way too rich in the low speed circuits and carbon up everything in site.

Fix the leak issue first then decide if anything needs to be adjusted.
 
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#5
I will go that route and see what happen's.

My buddy likes me once it's going but it's painful to watch his face start it.

Thanks !
 
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#6
84 XR250 starting ?

The saga continues ...

This bike now won't start at all even with a new plug ?

The newish plug came out dry black fouled, put a new plug in a no startee. We tested the spark kicking over with the plug out and NO spark ?

Where to look ? :yikes:
 

Studboy

Thinks he can ride
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#7
You must have bumped or grounding out something when you were cleaning the carbs. Check all of the wires if that doesn't work, unplug the kill switch and try it.
 
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#8
I'll check that as well but here is some further detail.

Since cleaning carbs, air filter, new plug, etc. months ago it seemed to run well but was hard too start at least when hot. I then found out the plug gap needed to be .033 or as close as possible. Eventually getting a new plug with that gap, now it does not start or have any spark. It was running, not that well, we ran it for awhile then it sat for a few minutes and it would not refire ? We changed plug (nothing else) and now it does not start or have a spark at all ?

Is there a CDI ? or something that can go ?

How can it be tested ?

Thanks !
 
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#9
scairns said:
was hard too start at least when hot. ? We changed plug (nothing else) and now it does not start or have a spark at all ?

Is there a CDI ? or something that can go ?

How can it be tested ?

Thanks !
scairns.

A couple things to check.

Unscrew the spark plug cap from the high tension lead. (Wire coming from coil.) Check the end of the wire for oxidation. If the end of the wire has a white chalky look to it or any sign of rust, cut about 3/8" off of the end of the wire and screw the cap back on the wire.

While you have the cap off, take a screwdriver and remove the screw from the inside of the cap, where the spark plug goes. Inside, there will be a little resister and a spring. Replace the resister with a piece of copper rod the same length as the resister. This is a radio resister.

Also check the pick-up coil. This is the little square coil inside of the right side cover. It sits next to the crankshaft and they are very susceptible to heat. Over time they heat up and the insulation will crack and allow oil inside. You can check it by using an ohm meter on the two wires coming out of the engine case. I don't have the exact values for this but, a good service manual will.

Just my $ .02

Ol'89r