I need 2 cheapy dirt bikes and advice

**nzspokes** · 4th January 2015, 21:33

Originally Posted by biketimus_prime

Where can I buy an different idle fuel screw for my XR200?
When I turn it all the way out, the bike idles like shit, however as I turn it all the way in it starts running better and keeps on getting better until the screw is all the way in.
I suppose I need a larger needle?

Also we got my mate's bike started. Bought a carburettor boot all the way from hawera, thanks to Bailey motorcycles! She started right up because the carby is finally drawing air in from the intake rather than from the cracked boot.
However now it's started blowing a lot of white smoke and when left iding it turns into blue smoke. What the fuck.

Also camped out 3 nights at The Farm (www.thefarm.co.nz), great place! Few friends and I did dirt biking. Got a solid 2 hours in and only costed $80 including bikes and gear! In fact we loved it so much that we're booking another trip next week just to get a day of dirt biking done on saturday. There was also a dirt biking competition on, all the riders were amazing. Also in disbelief at how good the kids are. Can't wipe their own asses but clear bigger jumps than I'd dream of!

Your bike sounds like idle jet is to big. It is not the screw. But run it 2turns out and ride it to see what it goes like. then 1.5 turns etc. See where it runs best. Also check the jet size against the manual.

White smoke is either water or condensation. Blue is either rings or valve guides. Sounds like it needs a top end. Do a compression test.

**unstuck** · 5th January 2015, 06:45

What does the end of the mixture screw look like, should be nice and even with no ridge or hollow around it.

That pic is a pretty severe example, but you get the idea. I use a decent magnifying glass, you can then see stuff you may miss with just the eyecrometer.

**biketimus_prime** · 5th January 2015, 18:56

Originally Posted by nzspokes

Your bike sounds like idle jet is to big. It is not the screw. But run it 2turns out and ride it to see what it goes like. then 1.5 turns etc. See where it runs best. Also check the jet size against the manual.

White smoke is either water or condensation. Blue is either rings or valve guides. Sounds like it needs a top end. Do a compression test.

The idle screw being on the engine side of the carb controls the amount of fuel going in, if I turn it all the way in and it still runs well, it means that it is running too rich right?
I will turn the screw 2 turns out and see what happens. I believe it'll struggle to idle and run like shit but since I redid the float it may be okay.

I really hope my mate's bike doesn't need a top end. I feel like it may be a possibility as it was running lean before we sorted it and finally fixing it and riding it may have been the last straw.

Originally Posted by unstuck

What does the end of the mixture screw look like, should be nice and even with no ridge or hollow around it.

That pic is a pretty severe example, but you get the idea. I use a decent magnifying glass, you can then see stuff you may miss with just the eyecrometer.

The mixture screw looks fine, not perfect and shiny but it is not worn excessively in any way.

**biketimus_prime** · 14th January 2015, 17:40

Hey guys so I went and had a look at my friend's bike today. It starts smoking as soon as it starts up from dead cold even after a week of sitting there and just smokes and smokes. Pure white smoke, no tinge of blue. Spark plug is very damp mixture of what appears to be oil and fuel.

Could it possibly be running waaaay to rich to have white smoke like that?

The smoke smells like burnt matches and fuel and nothing like the usual burnt oil smell a car has. Is it maybe because 4 stroke bike oil just has a different smell when it burns?

To be honest I'm being optimistic, it is probably rings...

**unstuck** · 14th January 2015, 17:50

Im guessing running way too rich.

**biketimus_prime** · 14th January 2015, 18:02

Originally Posted by unstuck

Im guessing running way too rich.

Forgot to mention that we first got it started and rode it around and it was fine. It was smoking a bit after a few minutes of riding but not a huge amount. It was then after starting it later that afternoon that the huge amount of smoke started happening. Maybe a stuck valve stem seal or something?