air pushing up from HSN

[Munro31]

Hi guys, I'm new here and come from South Africa, I have a problem, I have noticed air pushing up my fuel tube then suddenly getting sucked back in, causing high temps and idlinging problems, I have replaced the tubing and i pulled the mill and sealed up the Carb and back plate, also as I'm a poor bigger I got this second hand and it has a. 28 mill but have no idea what brand, only markings on it is EX on one side and. 28 on the other

 

[Jam Racing 1]

If you can post a couple clear pics of your it is very possible someone can give you an exact id on it.....
when you say you see fuel being pushed up the HSN do you mean the actual needle or the barrel surrounding it?
you did make sure the banjo fitting with the fuel nipple on it is tight and oriented to the rear of the carburetor housing?

if the banjo fitting is loose it will cause poor idle and leak fuel so start with those and see..... also check and make sure the fuel feed and pressure lines are not on the wrong places, do not laugh I have seen this more than once....

 

[Munro31]

If you can post a couple clear pics of your it is very possible someone can give you an exact id on it.....
when you say you see fuel being pushed up the HSN do you mean the actual needle or the barrel surrounding it?
you did make sure the banjo fitting with the fuel nipple on it is tight and oriented to the rear of the carburetor housing?

if the banjo fitting is loose it will cause poor idle and leak fuel so start with those and see..... also check and make sure the fuel feed and pressure lines are not on the wrong places, do not laugh I have seen this more than once....[/QUOTE

 

[Munro31]

Thanks for the reply, no fuel leak on the line or on the Carb, if you stop the truck and idle air comes up the fuel line till about half way to the tank then it starts leaning out and sucking it back in the Carb, the banjo fitting is tight and orientated correctly not leaking fuel and checked for a leak and nothing, its a head scratcher! Will post pics when i can

 

[Jam Racing 1]

Well thats a start anyway, so you can try this and see with all the radio powered up, set the idle air gap on the carb to 1mm or so set the high speed to 3 turns out from the bottom of it's barrel, and set the low speed needle to flush with the housing and see if it will start and run, if it does, warm it up and try a bit of running and tuning the high needle and go from there...
Look around the forum and search tuning a nitro engine I am sure you will find some good info to read through...

 

[Munro31]

Thanks, been reading up alot on tuning and seems like i must check again for a airleak and back to factory and retune the mill, thanks for the help😉

 

[blown68ssrs]

Is your tank cap sealed?

 

[Munro31]

checked everything and sealed everything, tested it today and seems the problem is solved, thanks for the help guys