RE: perry pump for OS 120 AX - does it help
 

I've got the same probs with my .91 FX... leaning out in the midrange

Gonna try the above method this weekend see if that helps

RE: perry pump for OS 120 AX - does it help
 

McChiken, what size of prop are you using? I have had my OS 75 for two years with out any tuning problems. I have run 14x6 to 12x8 props with out any trouble.

RE: perry pump for OS 120 AX - does it help
 

McChiken,
Sorry I missed your post from 2 months ago, I don't frequent this forum much.

I always run my fuel pickup line to the rear of the tank just like normal.

I would check your pickup line for a split right where the brass tube ends inside the tank, you could have damaged it when you removed the front end off the plane. This would cause the motor to go lean when the tank level reaches the split.

RE: perry pump for OS 120 AX - does it help
 

Dirt torpedo,
Some of the early 91's had a problem with the backplate and the needle valve and Hobby Services replaced the defective parts under warranty.

I'm not positive what the symptoms where, but do a search here on the 91FX and I'm sure you will find it.


Here's a post about the issue, if your needle valve mount is molded with the back plate you have a early 91 that needs a new needle valve mount and backplate. Send it in under warranty.

http://www.rcuniverse.com/forum/m_33...tm.htm#3389895

RE: perry pump for OS 120 AX - does it help
 

Traiders , I started with a 14x4w APC . Then I had a 13x9APC pattern prop on it .

Stuntpilot , I ended up taking the tank out after I crashed cause it made it too nose heavy . It was 16oz hayes . I replaced with a 12oz dubro and all new fuel line . I did just get a E-Mail from GP sevice . I sent the motor in . I talked to a tech and he thought it was a heat problem cause it would run great up until it dies . It really runs awsome for 5 min . I can tell how big of difference the pump makes in transition and Idle . I hope Hobby Services find a problem with it so I can get this resolved and get some airtime with my Edge . I did take the head off and look at the cylinder and found no scooring . A fellow club member just sent his 1.20ax in with a broken case around the bearing . They gave him a brand new one . I hope they treat me so well . He has over 50 OS motors bought from Tower so I don't think they would question him . I only have 2 ax's .