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-   -   Running Rich ? (http://www.dirtbikeworld.net/forum/showthread.php?t=126402)

LAPPER 14-06-2018 05:53 PM

Running Rich ?
 
1 Attachment(s)
Ok guys I need a bit of help . Ive bought a two stroke Husky wr250 2004 as a cheap "as is" sort of deal . ( it was very cheap ok )

Previous owner said its just started running like it wont rev out .

It starts first kick , sounds great and seems good until about 1/4 to half throttle and doesnt want to clean out . Feels rich - plug was black .

Head bolts were loose - tightened them up

Ive leaned up the carb settings as far as I really dare at this point . Put the needle on top slot and a leaner main and pilot but its still doing it and I think there must be something else at play here .
Might try an different carb I have spare .

Float height seems ok .

Ive checked the muffler packing - looks good

Checked reeds - look fine. ( boyesen )

Power valve is opening ok .

Not sure what to do next ^nuts



Attachment 105541

Nutty 14-06-2018 05:55 PM

Quote:

Originally Posted by LAPPER (Post 2039000)
...Not sure what to do next ^nuts

Swap modules. Sounds like the spark advance curve is dead...

LAPPER 14-06-2018 05:58 PM

hmm . Ok thanks . Any way to test this ? Resistance readings ?

Rebuild 14-06-2018 06:58 PM

wet side crank seal?

choppiektm 14-06-2018 08:41 PM

Not fouling plugs?

LAPPER 15-06-2018 09:58 AM

Yes fouls plugs . I dont think its crank seal. It runs well until a certain revs. The primary coil resistance is only .5 ohm from what i can tell and secondary 17 700 ohm .

Sent from my SM-G900I using Tapatalk

LAPPER 15-06-2018 11:32 AM

I guess the coil could be ok but there is no way of testing the CDI with a meter . If I manually advance the timing at the stator and this helps this would be an indication that its the cdi ?

Nutty 15-06-2018 12:52 PM

Quote:

Originally Posted by LAPPER (Post 2039004)
hmm . Ok thanks . Any way to test this ? Resistance readings ?

The symptoms sound like the module, not the armature or CAS. Make sure it has a good plug. NGK BR9EG at 0.65mm. Also, peek in the air horn and make sure the slide is actually lifting the needle.

Given the dirty plug it may well be a RHS crank seal. They're only a few bucks, just swap it out to eliminate that.

LAPPER 15-06-2018 01:21 PM

Module >? Its an older combined coil / cdi type ignition

Could timing have slipped out a tad ?

Does crank seal remove easily ?

I did put a new plug in - BR7ES

Its not starting now . Still sparking but not firing up at all
Fired once .

If I get it going I will take it out to see what its like when its had chance to get warmed up properly

Only other thing I can add is its had a water pump issue fixed recently by previous owner but when I replaced the gear oil it was milky looking and he said he replaced oil . .

Nutty 15-06-2018 03:30 PM

Quote:

Originally Posted by LAPPER (Post 2039049)
...Its not starting now . Still sparking but not firing up at all. Fired once....

Sounds electrical. Sparking outside the motor means little. Maybe a DBWer has a spare ignition you can try...check the armature winding and CAS resistances are up to spec. Also check the rotor magnet is still strong.

Eyeball the plug, a leaking crank seal will fail the plug and produce a similar set of symptoms.


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