YAMAHA WR 250 2 strokes 98 not starting

[antorider]

Hi Guys,

I am in trouble with my YAMAHA WR 250 1998 2 strokes. The problem, it does not start. How the problem came: one day triying to start it, it did for a few seconds and stoped, it did not start again, I tried for a while, no way. There was a bang whilst kicking. I thought the carburator was dirty so I did a detailed clean up, spark plug condition is fine and so the gap is, I tried anyway with a new one. So, the carburator is clean, the spark plug is ok, mixture is fresh(32:1), I know fuel is in the carburator, compression is ok(top end was done in December 06 and have not rode a lot) but no results. I believe It can be a firing problem. So I will appreciate some guide to perform trouble shooting on the electricals or whatever to find out what is the problem.

Thanks

 

[2 strokes for life]

antoriderm, the timming could be off. But i doubt it. Also, check to see if there is good compression.

 

[76GMC1500]

How do your reeds look?

 

[antorider]

antoriderm, the timming could be off. But i doubt it. Also, check to see if there is good compression.

Thanks guys,

I installed a brand new spark plug (japanese), the bike started at the first kick, previous spark plug (brand new but made in Brazil was faulty).

Regards :laugh:

 

[rmc_olderthandirt]

Thanks guys,

I installed a brand new spark plug (japanese), the bike started at the first kick, previous spark plug (brand new but made in Brazil was faulty).

Regards :laugh:

I have never even heard of a faulty sparkplug.

It sounds to me like the bike was flooded and it took two changes of the spark plug to clear it. A flooded four stroke will clear in a few kicks and maybe a new plug. A two stroke can flood so badly that you may have to turn the bike upside down to clear it.

If you encounter that situation again my recommendation would be to turn the gas off so you can't flood it anymore, then kick it a whole bunch with the throttle wide open. You can also get someone to tow you a bit. There should be enough gas in the carburetor float bowl to run for a minute or so, so don't turn the gas back on until you get it running.

Rod

 

[84cr125]

I have never even heard of a faulty sparkplug.Rod

i disagree, i have a br8es plug that i swear did not work, i abught it for jetting and it has never worked.

 

[antorider]

I have never even heard of a faulty sparkplug.

It sounds to me like the bike was flooded and it took two changes of the spark plug to clear it. A flooded four stroke will clear in a few kicks and maybe a new plug. A two stroke can flood so badly that you may have to turn the bike upside down to clear it.

If you encounter that situation again my recommendation would be to turn the gas off so you can't flood it anymore, then kick it a whole bunch with the throttle wide open. You can also get someone to tow you a bit. There should be enough gas in the carburetor float bowl to run for a minute or so, so don't turn the gas back on until you get it running.

Rod

Yes, your right, it is unlikely a faulty brand new spark plug. What made me suspect about that was the spark size and colour, this was small size and not a blue one. I remember in a thread a guy said about the spark: It should be a fat blue one.

Regards