Starts with Choke.. dies with any touch of the throttle..

[Lord_Muck]

Just read the whole thread, good to see you made some progress.

Just a suggestion if you can't find the right Mikuni part perhaps try a "Hoses & Couplers" or a "Bolt/screws" type of shop and you might be able to match up some sized threads etc, might take a bit of time but would only be like a $2 part (be sure to be nice to the poor blokes behind the counter, scouring high and low for a part your only going to end up paying $2 for) or swing em a few extra dollars/beers for their trouble.

Be sure the materials/metals are compatible too if you are going to do that.

[davexs250s]

Thats great! Might order some and give it a go, thanks so much for your help mate. Lots more to choose from when search xs650/400 etc....

any suggestion for removing the broken piece from the hole?

[Triple]

nah mate, find someone that can drill it out for you properly, dont even think about trying yourself haha

[davexs250s]

well after a few back and forwards got the snapped screw drilled out for $30.00

new screws in both carbs.... and....

bike runs on choke only (dies without choke) but seems to rev alot smoother and can ride it around

still can't get it to run without choke!!

Could i be too rich or lean?? the carb is spotless inside have cleaned it so many times and can't find any leaks

fk a mother.. ;D

[hudnut]

I have an 81 XS250 in pieces right now. Starting rebuilding one for a mate. Started putting it back together on the weekend. Now to your problem. When he bought his dunger on ebay I had a play with it to get it running around the front paddock to see what we were dealing with before we started pulling it apart.

It did exactly what you are describing. Started ok (with some coaxing), then died if you started upping the throttle. Also fluctuated in RPM sometimes.

I reckon you've definitely got a leak. We had issues with getting the rubber manifold going from the carbs to the filters not sealing perfectly, having small cracks in it etc. Solved by wiping silcone around the inside of it. Was better, but not great. Added pods filled will with foam to eliminate as a cause. Ran better, but not perfect.

Then we found leaks on the gasket surfaces either side of the spacer that goes between the carbs and the head. seal them up. No problem.

To help diagnose if you have an air leak issue, try spraying (carefully), some Aerostart (ether) around the carbs an see if the revs rise as a result of the ether being sucked into a leak. It is very obvious. Make sure it doesn't get near the filter intakes, or the test is void as it will suck the ether in that way.

I've also checked the float bowl level by clamping the carbs (bs32) to a bench and jamming a clear tube into the drain hole in the bottm of the float, bend the tube up beside the carb and measure against the side of the bowl. That will give you the exact fuel level. Check both carbs to make sure they are the same.

[hudnut]

The other thing I've also heard of is leaking through the rubber plunger covers on the choke rods where they enter the carb. Wasn't a problem for us though.

[davexs250s]

Idle mixture screws turned out 2 more turns and runs like a champion, woohoo.

Went up to get a blue slip but they won't pass it with the pod filter, fk!.

Anyone got an airfilter box that may fit to sell?

thanks