os 37 starting problems

[Dilbeck]

Hello have a os 37 engine, runs great, idles great, but when it comes to starting it not so great. It takes approx 30 to 45 seconds to start this engine with new glo plug, charged glo starter, charged starter exc. Starts everytime but seems to take forever or maybe thats just the nature of this engine. Any answers would be helpful.

[Aztek1701]

Hiya,

Im no engine expert but it sounds like a pressure problem (lack of) you could check the following..

1. Check that the exhause pressure line to the tank is in good condition. (Without this the fuel doesnt get pressurised and is slow to move into the engine)
2. You might want to richen slightly the idle needle. This is the screw slot in the barrel of the carb. (dont move it much cos its very sensitive).
3. Cover the exhaust with your thumb while cranking, that sometimes helps to build the pressure in the tank.

Hope this helps... Azzy

[hawkman]

When I run a nitro engine I use the starter without the glo battery...just give it a few seconds...this primes the engine...attach the glo and start..it should go straightaway...

Rob

[Dilbeck]

thanks guys. I may even be starting it wrong, I cant seem to tell when to pull of the starter because the cranking makes so much noise it hard to tell if its wants to start. A lot of times it starts running backwards (70 % of the time) and i have to idle down till it starts running the clockwise direction.

[hawkman]

It might be a bit too rich if its running backwards on start...I could be wrong.

A good idea is to first turn the starter shaft by hand....just a couple of turns. This makes sure the bore is not full of fuel...which can sometimes happen...but clockwise? a starter shaft that has a one way bearing would be a good idea..I always though the engine would run anticlockwise...looking from above looking down on the engine (viewed from the front in other words).

Be careful with engine tuning by the way....too lean will overheat the thing...best way is fly around...land and go to idle...feel the backplate with a finger...it should be warm...but not hot....if its hot then the engine is running lean...so you might need to richen it a tad....BUT overheating can also be a result of blade pitch being too much at a given point...OR..tail drive is binding...or too tight if its a belt drive.

A good indicator is the skid below the exhaust...if there is some oil on this then you should be ok.

Rob

[Dilbeck]

Thanks. It was the way i was starting it. The starter shaft does not have a one way bearing ($%#@) . I primed it then started cranking just a few turns and pulled of the starter, did this only three times and she came to life! Guess i was just cranking and cranking all the while my poor 37 was being held back.

[hawkman]

Yeah...sounds about right...if the porting was altered slightly the engine would run just fine going the other way...you could put a sticky 'arrow' on the canopy showing the correct rotation

Hawk Pro is it? I had a Sport version....excellent heli...really enjoyed it...just that nitro is expensive and hard to get where I live....check out my pics on this site to see the Hawk I had.

Rob