HELP! DT50R not idling.

[Bikeless]

Hi,
Mates son has bought a W plate DT50R and it won't idle,its been many years since I've messed with 2 strokes. The carburettor has no mixture screw,just an idle screw and the throttle slide is a rectangular bar with no needle,I'm used to a cylindrical slide with a needle,idle screws,jets etc.
Cleaned it all up but it won't idle,there is some slack in the throttle cable and the slide has a bit of damage on the idle screw part but still lifts when adjusted. Bike has a 63 main jet,standard pipe and a cone filter.
Cheers.

[Bikeless]

Anyone know anything about these carburettors?

[Bikeless]

Thanks for all the help

[Major Doss]

Chippy reply to your own thread, no?
However, a little bit of searching will reveal that a 'cone' filter will inevitably screw up everything whilst improving zilch.

However, 63 is correct main?
Correct plug installed?
Air leak from anywhere? Could be anywhere, from the manifold, crankcase or the main seals on the crank, etc..
Plug chop. What's the colour at different revs?
Has it had a partial seizure?
Shit battery?
Main bearing's on the way out? They will knacker the seals.
Two strokes need a lot of attention to get right, no manufacturer in GP is moaning about the switch to 4T.
No mixture screw orly? And the mixture has been effed about with via the 'performance' cone filter?
Yamaha should and will furnish you with specs relevant, buy an airbox for the model off fleabay, and get back to us with update.


Quote 'slide has a bit of damage on the idle screw'. Replace.


Erv Kanemoto didn't make a career out of blindly tossing questions out there on the tinterweb (granted, it didn't exist for the majority of us), so give BCF a break if no one can come up with a instacure! In this day and age, are you expecting a 'fit a 97 main, red power band and be sure to run on 20:1 petroil mix whilst the autolube is still connected' type answer?
Show the cone the bin, the only decent cone is the one you roll and smoke.

Kenny Roberts' bike was a two stroke that didn't idle, either. Didn't stop him winning 3 World titles....