You don't need the extra shim for running 30%. The motors are shimmed for up to 30% straight out of the box. The extra .2mm shim is just for lowering the compression during break in period. Once the majority of the initial metal pinch has gone you can remove the shim. Don't leave it in for too long - around 12 - 15 tanks depending on your break in method will normally be enough.
If you are running 30% it is a good idea to go to a medium temp plug with the higher nitro percentage.

is everyone running the go t3 plug on 30% still or a cooler plug?

I use Odonnels 97T and tested a GO, but went to T6 as T3 didnt liked so much ...

I am also running the O'Donnell 97T med plug on 30% and love it.
These plugs last very well, and performance is brilliant - plus they are not expensive. I also ran this plug on 25% and it was great.
The T3 is fine on 25%, but I just prefer a cooler plug on the 30% fuel.

yea thats what im thinking,the T3 plugs were great on 25% but since ive gone to 30% ive had a few tuning issues and the plugs seem to go off quite quickly.

maybe i should try the T4 plugs?

The T4 is still a med/hot plug. To be honest I think you would get better performance and longevity from the OD 97T on 30% :cool:

I used teh T3 plug for breakin, just cause it was in the box. I use 97T plugs, cause thats what my modder/engine builder says.. and plus... they are $5!!!

here in the uk they work out to about $10,same price as the GO plugs so cost isnt relevant really,just want something thats going to last.

when the engine is on the sweetspot the T3 plug seems to go off very quickly,maybe half a gallon if that and then the engine starts to go boggy as the plug starts dying..

as i said with 25% no problems,and thats with the extra shim in,ive got some OD 97T's ordered but i have a buggy national this weekend so get that out of the way then test the plugs.

If your running your motor with the extra shim in - take it out !!
You will have much better performance and economy with that shim removed.
It is only for break in to lower the compression a little and take some strain of the rod and wrist pin. The motor is not designed to run with that shim in under normal conditions (ie once it's broken in).
You won't know yourself when you up the compression a little to where it should be :)

Should I be removing shims or anything when I replace my conrod?

I have used 4 litres of fuel above the 1.5 I used to break in.

Seems to be a bit of confusion on the shim thing. Here's the deal.

The GX Series (and earlier model) motors come from the factory fitted with 1 x .3mm alloy shim and 2 x thin .1mm copper shims. This is what you should be running for 25% or 30% fuel.

The other .2mm copper shim that comes with the motor (in the plastic bag with the cardboard backing) is a "run in" shim. It is ONLY fitted when the motor is brand new before you start run in. Once you have done 12 or 15 tanks and the very severe metal pinch has subsided, you remove this .2mm shim and put it away somewhere for safe keeping. It is NOT required to run 30% fuel. The motors come shimmed from the factory for up to 30%.

Boxhead - no need to change anything when you replace your rod. Just check on the head button and make sure you have the 1 x alloy and 2 x thin copper shims fitted and your good to GO (no pun intended).

Some people like to experiment with removing .1 or .2mm of shims for slightly better performance and economy, but this can make the tuning a little more difficult. The motors run hard with the standard shimming and are a breeze to tune like this, so I don't really think for the average racer it is worth it.

25% run a medium or hot plug. 30% run a medium temp plug. With the standard shimming and these plugs you will have performance and reliability to burn :cool:

does the older GO piston/sleeve set suits the new school break-in method?we all know that the older versions have those nasty metal pinch,im thinking of applying the new school method to my new p/s/c set.

Yep. The heat cycle method is great for the older tighter PRS sets (which were very tight). Make sure you heat the cylinder area very well before trying to start, and maybe even loosen the glow plug slightly to ease the compression and get the motor turning over. Once it's running get it off the starter box and running on the ground straight away, just slightly rich with the head foiled to keep a good temperature in the motor. Cool running and idling it on the box for a few tanks is murder on a new motor.
Check out the break in info on the Tech Tips page of our web site at www.go-racing.co.nz

The older Gen 5 and earlier models took a lot more tanks than the new GX motors before the pinch subsided (around 2 gal in some cases).
The new GX motors have the sleeve fit just right. The majority of the hard break in is done within 12 - 15 tanks, yet the motors hold that last little bit of pinch and wicked compression well into their racing lives. Seems GO have got the formula spot on with these new motors.

If you can, pre heat your motor everytime before you start it from cold.
This will increase the life of your motor heaps. It's not always possible, but do it whenever you can.

When breaking in the GX engines, be sure to preheat (at the top of the case) to 200 degrees Fahrenheit before turning over. Make sure you preheat until break-in cycle is complete.

I think we need to read mm's shimming 101 on the massive mods web site. I am running 2x.1mm copper shims on my mg-66. so that gives me a total of .5mm head thickness. .3 built into the engine. this is running the amain fuel at 25%,with a os-p3 plug. I have used the od-97t plugs but they only last half as long as an odonnel plug. at least for me.