Problems with an old nitro engine

[stebedford]

Hi all, ive got an old nitro car with a .21 engine. the engine was seized up when until a few weeks ago, i managed to get it free again but now when its in the car it takes a while to start (using the pull start) and when it does start it runs for about 5-10 seconds and then stalls. the carb is clean, ive took the air filter off to make sure fuel gets in there. ive tried putting fuel directly into the carb too but its the same effect.

ive tried adjusting the fuel mixture but nothing else seems to work.

anyone got any ideas?

I was wondering if there might be a problem with the clutch?

[firestormmac5]

what the compression like on the engine?

[stebedford]

being completely new to rc cars i have no idea lol, how can I tell if/how much compression the car has? sorry for the noob question lol

[BRS]

Take the motor out and hold it by the flywheel turn it over till you feel the compression. The strength of the compression should be enough to hold the motor out at 90degrees to the floor. If the head flops over and straight down its knackered

Hope you can follow that its early

[stebedford]

ill give it a try when i get home from work, im guessing i do that when theres no fuel in the engine?

[dave g]

not knackered as such..if you know the right person he can resize it for you

could be many things while its stalling,idle screw too low,too rich on needles,plug on its way out,clutch engaging too early(bad springs/shoes/bearings) etc...even gumming around the crank bearings can cause this on old engines.

dave

[stebedford]

Ok doing that thing to test compression it seems quite good, its recently had the bearings in the clutch bell replaced. Just tried to start it not, it ran for about 3 seconds then cut off

[JonyNitro]

screw the idle screw in more so it will rev higher,when the clutch engages??ps what engine is it?

[stebedford]

its made by Prafa (no longer trading and about 20 years old) its a .21 engine. Tried screwing it in more, nothing, when it does start it doesnt rev very high, then it just cuts off after a second or 2

[lukeallen92]

Check its pulling the fuel through, i had this problem a while back. it turned out that the fuel pipe nipple in the exhaust was blocked.

[stebedford]

Originally Posted by lukeallen92

Check its pulling the fuel through, i had this problem a while back. it turned out that the fuel pipe nipple in the exhaust was blocked.

The tubes are fine, ive primed the engine by taking the tube off the exhause and blowing down it. now sure how to test the exhaust itself though, fuel does come out of the end of the exhaust in small drops now and then when i try to start it