40% Mugen Fuel
 

I want to jump from Trinity 25percent to Mugen 40percent. I know I would have to reshim the motor. I hear from local experts that the mugen 40 was the way to go. As long as I pick a fuel with good lubricity I should be good right?

i wouldnt do it... i have tried 30%, 25% and 20% on .21 engines... i now like 20% best coz i can still get good power and run reasonably cool. but i save about $1 a litre on nitro that i dont need :tire:

What size engine are you running? Are you running offroad or onroad?

:eek:

My idol......

I'm gonna be using it in my STS D5 mounted in my Prospec.

:blush: To be safe I would put two .1 shims in the motor.

you cant get a better answer than that (mike)

but doesn't 40% kill microcast piston motors.

i busted a brand new rex rer12s3 motor last vegas race. two practice runs with 40% byron and the motor lost compression and was gone. (motor had extra shim also)

motor was broken in properly of course but with 30%.
i used 40% in vegas to have that extra edge but unfortunately, i lost the motor.

i spoke with dennis richey about this and he said i wasn't supposed to use 40% on my motor. but if i had the older piston style (not microcast), they are safe to use with 40%.

No, from what JP has told me that it is safe to run up to 45% nitro. I run 30% for runtime issues but the guys on are team that use 40% do not have a problem.

are the jp motors equipped with microcast pistons?

you know it may be the byron fuel also. i've never liked byron fuel. but i used it for a while earlier this year to save some money because they are cheaper. but now i'm back to using odonnels again which i've used consistently since i started racing rc cars. but i'm going to try the mugen 40% with my microcast motors.

Yes, The JP's are with the microcasted pistons.

Mugen fuel and Byrons fuel are the same.

there must be some other factors i did wrong when i was in vegas then. i'll do more research and testing and hopefully i don't spend too much in the process. :D
anyways, thanks for your quick replies.

Hey Mike did you use the new Jaco's for the Nat's? I want to see a picture of them.

i run only 15% in my RBC4, i tryed 25% but it ran crap like it was to rich,
so i thought what is the point of shiming to go higher in nitro, just to keep the engine cooler? it has heaps of power already and is running cool.
a colder plug helps with higher nitro as will dosn't it?
it seemed while it had 25% in it it needed to be leaned up quite a lot, but i was not to keen on doing that because this reduces the engines lub
what do you guys think?

No, I ran Kawahara tires at the Nat's.