fireman7875

My Feedback: (7)

I am looking for a low speed needle valve or an entire carb for a Magnum .40 GPA. Anyone know where I can get one? Tried Global and Hobby People with no luck. I believe the barrel diameter is 10mm.

Thanks,
Brian

w8ye

My Feedback: (16)

EDIT: This is apparently wrong. See the post by the originator down below

The Magnum 40GPA has a lot of commonality with the Tower 40 and the OS FP40. In fact, the Magnum 40 GPA, Tower 40 and the Thunder Tiger 40GP are all the same engine except for the name on the side. This engine has been out of production for 10 years.

Also the OS 40LA carb will fit but it is rear needle valve.

Is this the way it looks?

http://www3.towerhobbies.com/cgi-bin...?&I=LXJB23&P=7

Here's the carb rotor
http://www3.towerhobbies.com/cgi-bin...?&I=LXJB42&P=7

Here's the whole carb
http://www3.towerhobbies.com/cgi-bin...?&I=LXJA91&P=7

Throttle stop screw

http://www3.towerhobbies.com/cgi-bin...?&I=LXJA93&P=7

fireman7875

My Feedback: (7)

Nope, the .40 GPA has a two needle carb not an air bleed. The Tower, OS FP and Thunder Tiger GP .40's are all single needles with air bleeds. I did some more research this afternoon and cross referenced some magnum engines to find out that the low speed needle on the XL 15 (which Hobby People still carries) is the same as the .40 GPA. I ordered one this afternoon so assuming my info is correct the problem is solved. Apparently the associate at Hobby People didn't know the two engines shared some parts. I bought this engine at a liquidation sale for $20 NIB for my brother's trainer. It ran great until the needle fell out in the air (I can't even imagine how that happened).

Brian

bigphil

My Feedback: (6)

The low speed needle is prevented from rotating only by the tension of the o-ring that also seals it in it's bore. Once the o-ring gets old and hard, it exerts little if any tension against the wall of the bore and then due to vibration of the engine running it can just walk out. Since most of us don't fool with the idle needle once it's set, this problem can sneek up on you without you knowing it until the needle starts walking. Unfortunately, yours came out completely.