Driving me mad I tells ya.

[Bruce CurtisMember]

The carburettor off My young fellas KX60 is that what it is.
Story
First topend rebuild, did some cylinder work, modified the pipe some more and just gave the carby a clean and rejet.
Finally got the final radiator hose for it last week (slow boat from shanghai) and fired it up yesterday. Ran it through a few heat cycles and all was sweet, got him started and he did a few runs round the house. Bike was idleing like a champion running fine around the house then all of a sudden ut starts pissing fuel out of the overflows everywhere and stalls. So i pull the carby and check out the fuel level…. Mmm all ok, nedle and seat seem fine and floats aren’t leaking, so I set the tang up to rediculous lean, put it back on and the same thing two laps of the house fine then fuel everywhere, so I pull the carb again and blow it out, put the level to factory setting and again it does it.

Now I’m stumped, it’s as if the needle is sticking down, but won’t do it on the bench, and tapping it with a screwdriver on the bike has no effect.

Ideas, oh learned ones as I am almost embarassed at something so simple has defied me to fix?

Bruce

[murph the surfMember]

Hoping you get some answers Mr Blue as my postie bike is doing the exact same thing, dumping the whole tank of fuel while I was at work the other day. Also have adjusted float level and checked needle and seat???? Will get a new needle and seat today and see what happens??
Cheers
Murph

[Anonymous]

My 450 did it at Coffs last year before we were due for our 2nd day of riding. It won’t help you but the cause of my problem was the float sticking. With a bit of wiggle and blow out it never happened again.

Your problem sounds strange as you’ve had the carbie off twice and it’s still doing it. I hope you sort it Bruce, thinking about it a sticky needle or sticky float can be the only things causing it can’t it, how else would fuel leak out of the overflow?

[Anonymous]

Dick would like to say good morning Bruce Dick is curious was it a warm say hot day

[GregMember]

Never did this before the rebuild Bruce?

TB

[Bruce CurtisMember]

First thanks Gents

Dick, yes very warm afternoon, but not boiling.

TB occassionally, but not regularly (make sense?)

BC

[Anonymous]

Not the most scientific of tests but have you tried the ol’ tap with hammer routine when it’s doing it?

[dennis da menaceMember]

is the fuel cap vent blocked bruce. might be pressurising the carb

[Anonymous]

Dick was wondering is it a pressure build up in the tank caused by a faulty one way valve in the cap or blocked breather this forces the needle open thus flooding the bowl Dick has seen this before Dick must point out it only happens in slow going on a warm day that the pressure build is greater then the demand for fuel where in a higher speed more fuel demand application the blockage in the breather hose will cause the engine to starve fuel

[Bruce CurtisMember]

Good call Dick and Menace, a good chance of what it could be as the tank breather was refitted by the young bloke and while he usually does a good job he is only 9.

Moto yep, that’s what the screwdriver trick is, a tap with a screwdriver handle….

BTW the porting and pipe mods have made it a heap smoother running too, highly recommend them so far, will give a report when it’s run in and he’s riding it properly

I will check that vent hose tonight, thanks again gentlemen, mucho gracias…

Bruce

[DeanMember]

Good points above Boys Long shot but floats are still ok? Ie not holed or leaking?

Ollie

[Bruce CurtisMember]

Ollie wrote:

Quote:

Good points above Boys Long shot but floats are still ok? Ie not holed or leaking?

Ollie

Yep, first stop was to check them Ollie as i had carefully set the carburettor up on the bench with loat level etc.
Plus I believe they are the solid floats, and while they can still fail it is much rarer.

Am tempted to see if a 24mm flatslide would fit in there, would improve throttle response in theory.

[Anonymous]

Dick did note that Bruce said the floats are ok

[DeanMember]

My Bad thanks Dick – sounds like dick and Menace might be onto it

Ollie

[GregMember]

I will be interested Ollie

TB

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