allan pedroza

Needs some help with my O.S.21tm on my t-maxx 2.5.
Last year i bashed my Maxx with new O.S. 21 tm and a 4 year old THS pipe but after 2 months there's a lot of unburned fuel coming out from the THS pipe and the truck become slugish so i tuned up my carb rich to lean, Sometimes it runs good then all of a sudden it become slugish again, With out adjusting any needle valve all of a sudden has a very poor performance,So i change the rubber cuppler,glow plug,fuel line and nothing happened,Then it came to my mind maybe the pipe so i put back the stock plastic pipe just to make sure if it will solve the problem and it runs good so from then on im using my old stock plastic pipe and now i have the same problems again.Alot of
unburned fuel coming out from the pipe that cause the truck with a poor performance and unpridictable tuning.
O.S.21tm is a good engine no doubt with that,Why it eats pipe?
Maybe because O.S.21tm is a bigger engine than the 2.5 that is why it rips the pipe, please help
Any idea will be appriciated.
Just want my baby back on the track even though my mate called it old school still proud to have it.

Thanks,
Allan

calvino

Sounds like you may have a pipe size issue. The pipes for a 2.5 (.15) are a lot smaller than ones for a .21, i would say invest the $$$$ into a new THS pipe for a 21 size engine and your probs should go away. Dont forget to peek over the engine for any air leaks as they can cause tuning issues also [8D]

allan pedroza

Hi Calvino thanks for the reply, You are right it is the tuned pipe issues,From my original engine TRX2.5 to O.S.21tm i didnt even bother to upgrade my tuned pipe,That is why when i switch to O.S.21tm with my onboard THS tuned pipe and stock pipe which suited for .15 engine only got burned in a matter of months and biside that since i have a stock pipe from my Savage 25 i try it on my O.S.21tm so it came out good not much unburned fuel and the performance came back to life it just proved that the problem is the tuned pipe size.

Now my next question is what is the reasonable tuned pipe that i should upgrade for O.S.21tm.coz i know the stock pipe that i installed are not good enough for my engine's performance, I know this engine could give more punch and power as long i have the right tune pipe.
Buku pipe is quite expensive right...

Please advise.