FalloutMan

Ive heard some people talk about it here so I figured Id post here. I read in a previous thread that the GO is shimmed for 30% out of the box and it comes with an extra shim. Someone said that adding the extra shim takes some of the pinch away to aid in starting while breaking it in. The problem is that I use 20% O''Donnell racing fuel and have 2 gallons of it (well, one is nearly empty) and I''d like to use the other gallon. From what I understand, if the engine is shimmed for 30%, then itll fire too late for 20%, so if I added the extra shim, itd fire way too late. So, should I add the shim and use the hottest plug i can find or should I just start buying 30%? What are the advantages of using 30% versus 20%?

sn00p

firstly theres not night and day difference between 20 and 30% yes it will run a little better on 30% but not worth wasting the fuel on unless your racing at a high standard. Your engine MAY be shimmed for 30% (i have no idea) if it is and you want to run the 20% it will run ok but by removing 1 of the shims it should fire better. wh e your out of 20% get 30% fuel and put the shim back in.

oh and try byrons generation 2 race fuel 30% ive heard nothing but good things on this fuel... odonells is 50/50 some like others dont.

Remember you will need to completely re-tune after changing fuels. start from stock if i was you

FalloutMan

I''ve heard that adding the included extra shim while during breakin will relieve some of the pinch and make it start easier. I wanna know if anyone has just put a hot plug in and use the 20% I currently use and had it run decently.

azzman

The included shim is a break in shim, that is all...def recommended that its use during this process, once the engine frees up take it out.

Paradoxmaker

Adding the extra shim doesn't do anything to the pinch, it lowers the compression slightly of the engine making it a little easier to turn over....

Vigilante212

Go here this is where all the Go tech guru's hang out they can tell ya about the shims.

[link=http://www.rctech.net/forum/showthread.php?t=177028&page=79]Go tech Guru's[/link]