Fuel draining into engine.

[mudnut]

G'day, all.
I have a petrol RB30, and fuel is leaking into the engine when it is shut down. Sometimes it will have a small back fire when started the second and subsequent times.

I undid the fuel connection to the front of the carby, hoping to get into the needle and seat. I only found a fine mesh filter, which had some minute metal particles in it and some type of tissue-like deposits on the housing wall.

I have only just started using a higher octane fuel, and the in-line Ryco fuel filter is only 1000 ks old.

My question are: a) Why is it leaking fuel into the engine?

b) Will the problem be solved by putting a kit through the carby?

c) Which carby kit is the best quality and value?

d) Has using the better grade fuel caused any build up of scum in the fuel system to let go and become a problem. If so, what can I do to fix it?

[paulyg]

The only way fuel can get from the carby to the engine is through the needle and seat,
I would start there, also check the float , have heard of them leaking and filling with fuel and no longer floating.

[mudnut]

Can I get to the needle and seat without pulling the top off the carby? Also, I saw the fuel level in the site glass drop within a few minutes of stopping the engine.

[paulyg]

If you take the fitting of that the fuel line screws to you should be able to get to the needle and seat,
if it looks good and clean then you should take the top of the carby of to check the float, but if you do that you may damage the gasket.

[mudnut]

I'll grab a gasket before I delve deeper.

[mudnut]

Does anyone know if Fuel Miser carby kit is a good one or not?

[threedogs]

when you turn the motor off just turn the key, some PPl give it a
small rev which IMO is wrong, coating the bore with fuel and washing off the oil

[mudnut]

Thanks, TD. I learned of that very early on and never have done it.

I had to replace the spark plugs and leads not long ago, because the engine was backfiring. I think it may have split the fuel float or some foreign matter is stuck in the needle and seat.