Couple of issues just need clearing up please :)

[ibiza_95]

right, when i come to prime the engine before starting, (i dont have a prime button) i blow into the exhaust outlet and therefore the fuel passes up the fuel line to the engine, but recently I've been blowing, and the fuel sometimes bubbles out of the carb... and then the fuel will travel back down the line back into the tank, instead of staying in the pipe. Also when the car is running it doesn't like to idle properly, and it ets the occasional air bubble in the fuel line.

The car is a second hand TC3 (associated) and I've just altered the settings for idle and high speed, as best i can to the conditions. I've had it running well previously but it just started doing this today (only had it a coupleof days)

But becuse of this i cannot start the car easily, as the fuel keeps running back down the line when trying to start it.

Do i have an air leak? or something similar or is it just something I'm doing wrong?

Thanks in advance
Ben

 

[rs4evo]

sounds like an airleak. check your fuel tank and fuel lines, or better yet just replace the fuel lines all together, they're cheap. take your carb off and seal the banjo fitting on the HSN and around the neck of it where it meets the crankcase with high temp rtv silicone. while you have the carb off, unscrew the needles and check the o-rings on those for any tears. take the backplate off and seal it with RTV also. reset your needles back to the factory settings and try her out. that should solve your problems. if you still have problems after that, it could be the front main bearing, the head gasket/shim, or possibly a crack in the crankcase itself.

 

[olds97_lss]

Is it hot when you see the fuel traveling back down the line? Is the throttle not at idle when the fuel goes back down the line?

It's sucking air somewhere or the carb is hot and boiling the fuel or it wouldn't be running back down the line.

 

[ibiza_95]

ok ill try it again today, now its cooled down, it should eliminate the heat issue, but yes it was hot when i tried it and the fuel was bubbling in the cab.
I've reset all the screws to factory settings so that i can eliminate anything like that also.

if there is no improvement, ill give the sealant a try and try and see if that helps.
I've also replaced the fuel lines
(its 7.29am here so i can't test it for a good few hours yet)
Thanks

 

[olds97_lss]

Most engines do that when they are hot. After you wait 10-15 minutes, it cools down enough to let you prime and start it again.

 

[rs4evo]

Most engines do that when they are hot.

thats good to hear, my car seems to vapor lock everytime i shut it down for whatever reason. i was worried that my mill was getting too hot, but I'm guessing this is a normal thing for most of us?

 

[olds97_lss]

It is if you have an aluminum carb. The key to that is not to kill it when re-fueling. Just let it run. And shut it off when you know your going to be doing something for 10 minutes or so.

 

[ibiza_95]

well i guess its going to be this issue then
Thanks for that.
Tried to prime and start today when cold and it did everything, but start on the pull first time so i guess its the heating of the alu carb