OS .28XZ
 

I am having trouble tuning this motor.:mad: Top end is unreal, bottom to 1/4 is a little fat. If I stab the gas it leaps. If I run 1/2 for more than 30sec than stab it, it looks like the bug man going down the track.:o I know it has a mid adjustment but every one says leave it at factory setting. What to do?:confused:

An OS engines, I almost never touch the mid....

Did you do the pinch test on the fuel line to determine bottom-end? Usually after I adjust the high-speed then bottom, I'm usually good to go...

How far away from the carb should I pinch?

I would recomend that you replace the carb restrictor with 7mm OS Speed restrictor, T2060 pipe to smooth out the bottom and if your running a Mugen or Kyosho ST-R use the Hyper heavy flywheel. We are haveing alot of luck with this setup our temps are at 200-220 deg and we are getting about 8-10 min runtimes.

where can i find this hyper heavy flywheel, i had heard that a heavier flywheel would calm it down alittle, mine runs great. ran it at the futaba nitro challenge, finished 7th in amain.

jlo

You can buy the Hyper flywheels at Tower Hobbies

So if nobody uses the mid setting, why did OS put it on the carb?:confused::confused:

Diito :confused: