engine to hot

[rickie]

I just bought the raptor thunder tiger 30 with the thunder tiger engine and it says to start out with the needle valve 3 turns open. Well I have done this and opened it up to almost 4 turns and it is still getting really hot and poring fuel out the muffler. When I get it in the air it starts to lose power and I have to land and then the glow plug comes out. I started with the O.S. A3 glow plug now I am running the O.S. No. 8. What do I need to do to fix this.

[hawkman]

You might be too rich....engine manuals are usually accurate...but will state that the settings are approximate.

Try this.

Remove the blades

reset the main needle....turn it all the way in....and take it out again about one and a half turns...

reset the idle needle...this might be hidden away inside the throttle valve assy...its a small screw....to reset...try this:

remove the fuel line off the carb...put some new clean fuel line in place...make sure the thottle is at its idle position...slightly open....screw the idle screw all the way in...but be gentle...stop when you feel resistance...gently apply air pressure using your mouth...gently open the idle screw (anticlockwise) listen for a 'hiss'....when you hear this STOP....the idle should be near enough ok.

go run the engine....but dont rev it too high....its ok to have the head turning...but dont go silly and rev the crap out of it...

if the engine dont start...and the glo plug is ok...just GENTLY adjust the idle setting...anticlockwise...you need small adjustments...

Fit the blades, assuming the engine is running ok, and go fly....hover around a while and make sure the engine runs well...smoke is ok with a splattering of oil on the skids....you dont want obvious signs of oil/fuel streaming out...hover around and land....shutdown....feel the backplate of the engine....its ok if its warm....but it should not be hot....another indicator is the main needle...if this feels hot the engine is overheating...but this might be down to the belt drive for the tail rotor...check the tension isnt too tight....it takes little to overload an engine....which has a tough job as it is.

The idle needle affects running from idle up to the hover point.....the main needle has a strong influence as well....but is more for the hover point up to max power....again you only need a click or two to adjust....always try to run a little rich....lean conditions are great if you can really nail engine tuning....but slightly rich will preserve your engine better.

So....in a nutshell...the carb/engine is reset.....you should be running and hovering about....anticlockwise makes the mixture richer....clockwise makes it leaner.....do small adjustments....dont ever loose patience....land at the first sign of trouble...if thats not practical...land as soon as possible...and re adjust....if you have training gear...fit it....beacuse if the heli acts up close to the ground the last thing you need is it tipping over and breaking.

Rob

[donaldhm]

Should also loosen and re-tighten head bolts. Follow alternate re-torquing, tightening each a small amount at a time following a cross pattern. Loosen carburetor mount screw and make sure carb is in tight and then re-tighten mounting screw. Also check that all screws for the backing plate are tight. What you could be experiencing is an air leak. The engine will always be running hot, and no matter how much you richen the mixture it will be hot and spiting lots of fuel out the pipe.

I found this to be the case with a few of my nitro cars, and would assume it would still carry over to helicopters.

[hawkman]

Yes...but a warm backplate means that the engine is running well, for helis.

Good and accurate points though. Too rich or too lean a mixture will cause overheating....You dont want too much oil being spat out....I used to check the skids on my helis...a fine coating of oil indicated that all was well...dont bother with nitro now though...gone petrol instead.

I did forget something though....you can do a 'pinch test' you get the engine idling and pinch the fuel line....some 3 to 4 cms back from the carb....listen to the engine....if it revs up a bit and dies out as soon as you pinch the line...the engine is set too lean....if it idles for several seconds then its too rich...it should idle about 2 to 3 seconds, rev up a little and die out...thats about the right setting.

Rob

[shanee86]

Wow glow plug comes out? Oh tighten that thing up and make sure it is tight if it still comes out then maybe your head is stripped did you put it in straight or have you ever put it in not straight? We had that happen to my heli and had to get a new head. Also sounds way to rich lean it out some and try that if that doesn't work then check everything to make sure it is tight.

[3dee]

Hi there, just a point, what nitro content are you using ? it could be too low this would make run hot. Is the frame in front of the head of the engine being cut away to give air flow to the head. My raptor 90 has a viper headed os cspec and i had to cut away most of the black plastic frame to get the engine to run well. plus a good fan quick UK do a good quality metal one thats better than the std. gray plastic. let us know if you sort it out.

[dooleyje]

Have you set the heli up? One thing is that you may be using tooo much pitch in hovering and /or your throttle curve is too low.

JIM

[rickie]

I dont know what to tell you. I had all the same problems as you and I could never get it fixed. I finally melted the connecting rod in half and locked the engine up. I just went and bought another engine.