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Hein
10-26-2006, 06:23 PM
Ok guys I have had a problem with this TT50 motor since day one. Please help I have had guys at my local club check this out but seems it is impossible to isolate the cause.

Fuel 15% nitro also tried 20 and 30%(30% seems to run pretty good and better performance) changed glow plugs (2xOS no 8 and 1xEnya no3) enya seems to work much better. Tried adjusting the pitch curve when the head speed increases seems to work somehow does not seem viable adjusting this every time. Tried lowering the throttle curve down also seems to work but starting still a problem.

What happens.
Low-end needle adjusted so the motor idles, 3.5 turns on the main needle. Constant height hover approx 10 seconds first say 8 seconds all is well but after the head speed gradually increases up to the point where the heli becomes unstable.
Set it down keep adjusting the low-end needle so it idles ok and head speed does not increase. Motor then runs and idles cool but a bit sluggish in the hover. Cannot lean the low end for performance due to the head speed increase problem.

Fuel up and cannot start/idle the motor due to the low end being too rich. Lean out the low-end needle to get it to start/idle. Constant hover same head speed increase as above once again need to richen the low end needle too get it to not increase the head speed.

Tuning and burning fuel mostly adjusting the carb not flying?

Taken the motor apart head gasket seems to be installed. Did notice the muffler gasket may not be sealing properly. Taken the CARB off checked the O-ring seems ok, cleaned out the carb once, checked the fuel filter seems ok. Checked fuel lines in and outside of tanks all seems ok. Not tried running the motor after taking it apart will do it this weekend.

I know this seems like a long post but I am desperate PLEASE help!

Jafa
10-27-2006, 04:45 AM
You have an air leak in the fuel delivery system...the engine is leaning out

This could be any one of a number of problems
A leak in the exhaust gasket or the exhaust it's self
A pin hole in a fuel line - including the clunk and exhaust pressure lines
A pin hole in the tank rubber stopper
A pin hole in the tank it's self

chooch
10-28-2006, 04:31 AM
I had some tuning problems when i first got my raptor with the tt50.I found that
the oriface in the carby housing behind the inlet nipple was very small.Approx
1.2mm. i inlarged this to about 2.5mm(i think)since then did not have to many
tuning problems.Might not be related to your perticular problem though.Hope you get it sorted

hookmaker
11-01-2006, 04:20 PM
I also went through a few months of tuning problems which look quite similar to yours. Kept tuning needles all the time because the backplate got too hot + had the same problem with increasing head speed after few seconds of hover all the time.
Michael at raptortechnique suggested it could be a few mm slop in the crank shaft causing the piston rod to grind against the back plate and thereby creating heat. This could be caused by the cooling fan not being tightened enough. THIS WAS the problem!

See this page for further info: http://www.raptortechnique.com/ts-engine.htm#9

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Hookmaker