I awoke this morning to find a strong smell of fuel.

I thought that is would more than likely be one of my many minimotos.But no.

There was a puddle forming under the MC18.

At first I thought that the fuel hose was cracked. But no.

After I pulled the tank and airbox off I noticed that fuel was dripping from the bleed/overflow(??) nipple on the fuel bowl.

As I stood the bike upright it poured out.

I saw the screws near the nipple and tried to tighten it up but it was already tight. I loosend it right off and let the fuel run through it thinking maybe a bit of grit is caught in there, tightend it back up and the same symten persists.

Is it just the case of pulling the carbs off and giving it a good clean out or has something inside the fuel bowl perished causing it to leak?

Bike has been sitting for about 6 weeks now unstarted.

Also I recently(3months ago) did a top end re-build. I took the bike out for a long ride after and it ran fine.
Then the missus took it out and she said that whilst riding in a straight line taking off from the lights, she was in 2nd gear doing 50km/h when suddenly the rear wheel locked up and came to a complete stop. She rang me up and I went to her aid. After having a brief look over the bike just to check if it was siezed, it seemed fine, so I fired it up and she rode home.
Any ideas on this symptom? And how to rectify.

Thanks!
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Paranoia about failure will ensure nothing but failure to ever reach potential.



MC18 Race bike project..
MC21 Race bike..

sounds like the float valve is sticking or needs replacement , turn the petrol tank off and drain the carbs, using the drain screw that you said was allready tight, stick a little pipe on the carb bowl and empty them.

its a case of whiping the carbs off, removing the float bowl and checking the valve, if it looks ok ie tip not a sharp even profile they may need replacing or more commonly they need a clean and the float height checking, best descibed by the manual. basically the float bowl is overfilling and petrol is escaping via the bowl vent.

Glen wrote:
After having a brief look over the bike just to check if it was siezed, it seemed fine, so I fired it up and she rode home.
Any ideas on this symptom? And how to rectify.

Glen, if the rear wheel locked up then its highly likely to have seized, in some way. You can't just look over the bike at the roadside and determine everything is fine. If it has seized, it could have grabbed and then freed off again, then allowing the bike to be rode home. But you need to take the barrels off for a proper inspection, if the barrels & pistons are clean then look at the crank.

All that excess fuel could have found its way into the crankcase, and washed away the oil film from the main bearings, leading to compromised lubrication.
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Rich
MC21 Track Bike / RS250 NF5 'Spencer', NX5 'Cadalora' & NXA 'Aoyama' / RS500 / Two Brothers Racing RC30

More often than not a 2-stroke will seize on the exhaust side, so you can take the pipes off and peer up the ports to see if there's piston damage.

Other things can [rarely] cause the back wheel to lock up, but 50p says it seized.
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Andy.
NSR-WORLD.COM

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Ok guys.

Thanks for the input..

I'll check it out and when I find some results I'll post them up..

Any info as to why it would have seized??
_________________
Paranoia about failure will ensure nothing but failure to ever reach potential.



MC18 Race bike project..
MC21 Race bike..

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Last edited by DifferentStrokes on Mon Sep 28, 2009 5:47 pm; edited 1 time in total

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