Won't start - backfiring

[imdying]

Have you always had to kick the shit out of it?

Correctly tuned, a single gentle prod on the kick starter will start it. Unless it has been sitting for a month or two, then you might need two kicks, but even then should go on two.

Having to kick it over more than once isn't a good sign... worse if it's been that way for a while (or been getting steadily worse).

[slimjim]

dude..also check fuel line filter...cause its sounds too like no fuel dropping in, and then when its drawning after a turn over and firing.. humm not running.. fuel line fuel filter.. then garge time,,

[quallman1234]

If its turning over i doubt the Powervalves have dropped.
Espically if it runs for a couple seconds.

Check the spark on both cylinders. Sounds like a bit of a foul'd plug possibly?

Is it hard to turn over or not really your just trying to kick the shit out of it because it won't possibly start with normally kicking.
Im with drew on this one, its probabaly something simple

[F5 Dave]

. . . what sometimes happens is there is a loud backfire type noise from the exhaust and then stalls. Othertimes it idles poorly for a few seconds before dying. ?

. . .So of course being a 2 stroke the first thing you did was put some new plugs in it, because that is exactly what will happen if they get fouled.

[nudedaytona]

. . .So of course being a 2 stroke the first thing you did was put some new plugs in it, because that is exactly what will happen if they get fouled.

The spark plugs are new. They are a slightly different type from the old ones. I'll have a look at them.

Cheers,

[F5 Dave]

if they are slightly wet looking then 50% chance some brakeclean or a spell under a gas torch may sort them out. or not.

As a total aside a pulsar coil that has been knocked away from the flywheel can cause same issue, but unlikely.

[Drew]

The spark plugs are new. They are a slightly different type from the old ones. I'll have a look at them.

Cheers,

Being new doesn't mean much, two strokes are a fickle thing, and it takes little to upset them.

[Str8 Jacket]

Being new doesn't mean much, two strokes are a fickle thing, and it takes little to upset them.

He is sooooo right! Sometimes they just go BANG!

[Drew]

He is sooooo right! Sometimes they just go BANG!

Only when you ride them luff.

[Squiggles]

Had this from Jafa's rd the other day actually, if we got it going, she'd die out quick or die before she revved over 4k, engine was warm after a while, several really good kicks and a quick trip to near the redline for a wee trip and she's all good now
Spark plugs were brand new (replaced them after it coughed out) but problem remained

[centercore]

My mates rg150 did similar things when it dropped a valve. We could push start it and ride around was like it had the choke on. It wouldn't idle either.

You could check if they haven't dropped?

[Drew]

You could check if they haven't dropped?

I stand by my statement that it's unlikely for both sets of power valves to clip a piston at the same time, between riding it, then trying to start it.

Plugs is the first thing to check.

[nudedaytona]

I took one spark plug out this morning. It didn't look too bad - just a little bit of oily stuff on it. I cleaned it up with a rag but didn't have time before work to put it back in. I'll try with the old ones too and see how it goes.

[Ixion]

Fit ne wplugs. A two smoker plug that doesn't look too bad is too bad.

[racefactory]

I'll second that- it's true about the plugs. get new.

Might be worth thinkign about if your bikes compression is shot as well due to worn rings/ extreme cases- barrels. If your bike is hard to start and a lot harder to start once it's warm that's a good bet the compression is down the drain. I had a look at an NSR250 the other day ( http://www.trademe.co.nz/Trade-Me-Mo...-175772824.htm ) that was so bad i could put it into gear with the engine off and the engine would turn over if i pushed the bike with my feet... I don't know how it ran but it took so many kicks to start.... sounded weak as shit too. When did you last have your top end done?