carb or running problem

[old git]

Just got my XR running but unfortunately it will only run when on full choke, even after letting it warm up for some considerable time it will immediately cut out when put to half choke or choke off. I have set the mixture screw to the handbook setting of 1 an 1/8 turns from fully screwed in, but it hasn't made a difference.

The bike starts easily enough but I can't get it to run without choke....


New plug fitter
New air filter fitted
Fresh petrol put in


Any ideas appreciated.

[jasonbc]

Just got my XR running but unfortunately it will only run when on full choke, even after letting it warm up for some considerable time it will immediately cut out when put to half choke or choke off. I have set the mixture screw to the handbook setting of 1 an 1/8 turns from fully screwed in, but it hasn't made a difference.

The bike starts easily enough but I can't get it to run without choke....


New plug fitter
New air filter fitted
Fresh petrol put in


Any ideas appreciated.

Whar xr is it? if it's a xr400 the mixture screw is wrong. for the 400 turn the mixture screw all the way in then 2 and 1/4 turns out.

[Daz Max]

Has the engine had any mods?
Exhausts etc can upset the jetting.

[jasonbc]

My bike is setup as bog standard i found the 162 standard main jet made it run too rich at the moment i'm down to a 145 and it seems to run smoother all the way through the rev range. No more, no less power just smoother.

That said i wouldn't think his problem is jetting

[catteeclan]

Has the bike been sitting for a while?

Bloked idle jet or split inlet rubber maybe?

[old git]

Thanks for the tips. I stripped down the carb and found that the idle jet was indeed blocked. Cleaned it out and the bike seems to be running fine now, not taken on a ride yet but once warm it ticks over fine without the choke, which it wouldn't do yesterday.

The 1 and 1/8 turns on the mixture screw is as per the Honda XR400R handbook, but happy to be advised by the experts if you find that another setting is preferable.

[old git]

Whar xr is it? if it's a xr400 the mixture screw is wrong. for the 400 turn the mixture screw all the way in then 2 and 1/4 turns out.

Bike is a 2002 XR400R.

Handbook says 1 1/8th turns but happy to be advised of a more optimum setting.

[jasonbc]

Bike is a 2002 XR400R.

Handbook says 1 1/8th turns but happy to be advised of a more optimum setting.

Thats strange my manual is a genuine honda manual for a 1999 xr400ry model and that states all the way in and then 2 1/4 turns out maybe it's to do with the weather pressure change between here and your country

[old git]

My XR is a UK bike, it was brought over by the previous owner. I will have to have another read of it and double check.