XLR poor starting and running

[supermoto1962]

Can anyone help with this problem:

I have an XLR250 which i bought as a non-runner. A little work and it now starts, runs for about one or two minutes then stops.

So far:
1. Cleaned and set carb as per manual
2. Fitted inline fuel filter
3. Installed a good working plug & checked for good spark
4. Set inlet/outlet valves
5. Checked electrical connections are good.

It will start with choke fully out and no throttle. Engine seems to rev quite high. Reducing choke to half the bike will revs freely.
Throttle can be blipped and less choke applied but all of a sudden engine stops.

Sometimes it will start if kicked up at once but more often it refuses.
Leave it for a while (usually while i remove plug to check if it's fouled) and it can be started again but same thing happens.

At a loss now. Any idea's? Don't have any spares to try.
Regards

[TRANSPORTER]

Its got to be fuel related, when you blip the throttle you say it dies, sounds like over fuelling, when you stop it or it stops itself and you take out the plug to check that you say that it starts again usually, I,m thinking that the time it takes you to undo the plug check it and replace then start again its giving the petrol time to evaporate and so allows the olds girl to start again.
I would deffo go down the route of checking all the fuel lines, (well all one of them) blow down the fuel line from the tank end into the carb it might be that a small amount of crap is in there somewhere, also clean out the carb with carb cleaner and also let some fuel run through the carb by taking off the float bowl and allowing the fuel to just run through.
Give these a go and you might get a running bike fingers crossed. although Im sure that another member will be along soon with some more help for you.

[todd5774]

Also try turning your tickover up. then when you turn the choke off the bike should keep running, you might be flooding it when you blip the throttle with the choke on. Definatley sounds fuel related, do you have the factory jet settings in or have you fiddled with the jetting?

[supermoto1962]

Thanks for the replies guys.

My thought is that it's fuel. When i have removed the plug it is too sooty for my liking. Should i be winding the mixture screw in or out to lean it out?

Have tried it with the tickover turned up and the choke on.
It revs quite high. Is that the norm? If so how long should i leave it until i turn the choke off, reduce the tickover and try the throttle.

When i cleaned out the carb i used carb cleaner and blew out all airways with compressed air. With the card attached and primed with fuel, i have blown down the pipe and it will caused the fuel to overflow, which i assume is the norm. All setting and jets are as per the manual.

My carb has a cable choke and not the lever type.Is marked PD790 C GG.

Plenty of spark present but could it be breaking down?

[todd5774]

Not sure about the air screw and mixture on a 400, you will have to wait for one of the others to tell you what it should be set to, however the tickover and choke i turn down and off as soon as its started, then let it warm for a minute or 2 before touching the throttle.

[kempouk]

have you changed the fuel in the tank, this some times causes problems having old fuel in the tank, also remove the fuel tap and clean that out.
as for the fuel air mix i ride an xr600 so i cant help with that one.