pointblank

I think the subject speaks for itself. The guy at the LHS says "you have to shim and run a cooler plug." I broke the engine in with Wildcat 20/18, which is way too much oil I know. Anyway, in your humble and "professional" opinions should I shim the head and run a cooler plug? I have been running the MC-59 but have a supply of LC-3's too. Also a nub question, If I shim should I remove the old shim or put both of them in together? Man I feel like a moron asking that.

2DMaxLST!!

On my LST's I have ran 30% from the begining with Machs (4),SH28,Collari .30,Collari .32, Sportwerks .26 and I use a cold Megatech Iridium plug or OS R5's and A5's. I've never shimmed and have had good engine life.

RCtruckRacer

The only time you would need to shim is if you are running a cold plug AND you are experiencing detonation. I run 30 as well with OS 8's, and have the stock shim on my mach, with no problems!

If you find you do need to shim, buy the 2mm one and use it by itself!

Good luck!!!

plecofish

confirm... with 30%, OS A5 or R5 short plugs do the job without change the shimming

LOOKIN

Is it ok to change the percent nitro you run in your motor? I.e. broke in with 20% and want to go to 30%?

captanabolic

You can change nitro content but you will have to change plugs and re tune. I think most manufacturers set their factory settings with 20% nitro in mind. Although my LRPZ-28 Spec2 Recommends cold plug and 25% nitro.

SublimeJason

I run 30% Nitro with 10% Oil and Never used a shim, I use Sidewinder Fuel & OS #8 Plugs.

SCHLEPP

My Feedback: (1)

30% and MC-9 plug since new, no problems with several different engines. Go for it.