Auto Scooter Carb problem...... Ideas on a postcard please!

[paulmgreen]

Right then auto scooter experts!


My sons Dragster 70 has started messing around again!

Its a 70cc kit with a Mikuni Carb,.... no model numbers on the carb, so I can't properly identify exactly what it is or the size.....but theres a pic below....


Problem is that fuel is coming out of the overflow of the carb at tickover.


I have stripped and cleaned...... no dirt anywhere, float bowl looks to be working ok.....


The excess fuel does not just drip out - but pours out!

Any ideas?

[drunkmunkey6969]

It has to be grit blocking/jamming the float cut off....either that or its worn out....or the float lip is bent and not shutting the valve when the floats rise.

Take the floats off....stick em in a bowl of petrol...to make sure they float! Then check the needle shut off valve to see if it is stuck, or worn. Then check the metal lip on the float arm, and see if it is bent or out of place.

[paulmgreen]

short term fixed... ! bent the metal plate on the float lol

[drunkmunkey6969]

only thing to be aware of now, is that the float bowl doesnt fill up as much.....but its better than p1551ing out everywhere.

My Lectron has a clear float bowl, with a 'level' marker but it was only filling to the lower level, and as the 38mm will be sucking in big gulps i whipped off the bowl and tweaked the metal plate/lip on the floats so that it filled to the 'upper level' line.

No need to go OTT as it should all be set to flow at WOT anyway, but just a 'peace of mind' factor.

[stokky]

my son has a dragster with a 70's kit on as well.

Interestingly when he had it originally as a 50 it got stolen, when we got it back, we had exactly same symptoms as you describe.

I never did fix, just got him the kit and a larger newer carb.

I have also seen this fault described by others on ebay and the like when selling dragsters, so think it probably pretty common.

Martin

[paulmgreen]

hhmmm...... interestinG!


the temp fix of bending the float needle bracket worked for an hour!

[shocky]

are the 50 drags like mthe 125/180 and have a petrol pump does it leak when not running i wonder if its to do with the fuel pump or try another carb dont go much more than a 18 or 20 max what happened to the standard carb there pretty good even with the 70 conversion or try on here http://www.italjetdragster.com/forum/ub ... p?ubb=cfrm