Ok swapping a kidney for a new gx 5 port i really like the GO race engines, im a peasant and rc on a reall small budget and these engines let me enjoy this hobby. I know i cant justify the big dollar italian popular brands.

Also for the price of replacement parts anyone can have a go at modifying them

so..........what you are saying is..................thanks to GO Engine you still have one kidney?

Wow, GO Engine even saves lives!!!
Have a blast, and hopefully your financial status will improve!

I do not use the break in shim, after a gallon or so I take one of the brass shims out. There should be only one alum and one thin brass shim for 30%, I say thin brass shim because I think the break in shim is a thicker shim.

Rex

Yep - the alloy shim is .3mm, the 2 x thin copper / brass shims are .1mm each, and the copper / brass run in shim in the packet is .2mm.

Rex, I have experimented with removing .2 and .3mm of shimming on 25%, but I normally run the standard .5mm of shims on 30% (with medium plug), which is what I have been running lately. I will take out 1 x .1mm shim and give it a go. A little better fuel milage with the .1mm shim removed ?

leave it alone grizz,I already tried and for the mg-66 it makes it a night mare to try and tune. on the other go-tec's it seems to help, but not the mg! I just got back from practice where I tried a few things engine suspension wise. What I have found with the mg once it's set leave it alone. same goes for the xray 808. not my jammin, I was always screwing with it to get it to handle. I have really learned after getting the engine and new car-if it ain't broke don't fix it!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Hiya Matt - yep, I gotta agree with you there on the X-Ray. Got mine right where I like it now and I don't change anything - except dialling in a little more steering at the second track I run once a month, but everything else stays the same. For me and my driving style it is dialled, so I don't see the need to experiment too much. Maybe I'm missing out on a smidge of something here and there, but it's good enough for me

My MG I tend to leave alone. It's more the GX motor I run for club days that I am playing with. I get a little better milage by taking the two .1mm shims out, but it is harder to tune and the idle is a little erratic I find.
Currently experimenting with some smaller restrictors and standard shimming.
It's all good fun

Just got a go tech .25 and almost done breaking it in. Everything has been going good. Can't wait to really open it up. How do i get more stickers for the new body I'm doing, I'm willing to pay just need some more. Thanks

I purchased a non GX 3 port race last season and I have been having troubles with the low end since. When the motor heats up, the bottom end gets real soft almost like a broken clutch spring. I've replaced the whole clutch setup, sealed the whole motor, and even put in new carb orings! Today I borrowed a friends Nova carb and the bottom end got much better but still get soft at the end of the tank on the track. I KNOW the engine is tuned correctly. I even had Ed Bridges from EB Mods tune the motor and it still eventually got soft on the bottom. I've checked tank pressure and replaced all the lines. What's the deal? This is a pretty discouraging first time experience with GO Engines.

i had this prob also, try richening H/S/N 1 hour at a time as you are loosing preasure towards the end of the tank, this fixed my problem, JMO
also check that the fuel line inside your tank dosen't have any holes in it towards the pickup end in the bottom of the tank !

Hmm - I know you say the tune is right, but to me it sounds like possibly one of two things.

1 - you have the HSN just a tad lean (depends on carb type - long or short needle). This can cause slight lean bog below half a tank. Remedied by going 1 hour richer on the HSN at a time until it goes. More prevelent on the long needle LSN carb.

2 - your idle gap is too wide, which is disguising a quite rich bottom end and a lean top end. Motor will run OK, but will start to lean out at the bottom of a tank and come in a tad warm.
Check the idle gap and make sure it is .7mm or use the pinch test to see how high the motor revs up when it is still quite cold (run for a minute on the box, then pinch the fuel line). Motor should only rev up very slightly then die. If it chirps up quite high and quickly in the revs, then the idle gap is too big. Lessen the gap until you get the right result, then retune botton end first, then top end. Once you set the gap like this, if the motor is reving too low and wants to stall - lean the botton end to bring the revs up - DO NOT ADJUST THE IDLE. If it won't idle with this gap, then your needles are wrong somewhere.

Hope this helps.

Your motor may have the long low speed needle which will tune differently.

Rex

just ran the mg66rr hand prep and breakin by massive mod on my mbx6t with asend clutch... 1 word.. sWEET!!! More top end then the go.25 and bottom end is a blast! Felt like my go .25 engine. Best money ever paid so far.... Thank u all for such a excellent engine. I bet it flys on a buggy! I could chase a xray 808 on nova toro anytime. Rreally good stuff and i'm impressed.

He he - yep, they are nasty fast in the buggy mate
Not too many big name and expensive motors will catch, much less pass the 66.
Value for money has to be 10/10.

grizz, did you put in the hsn/lsn from massive mods? If so what is the difference? easier to tune? also the other turbo head,the one that mark modded. The needles are for the mg-66.

What pipe is recomended for the go 7 port being run in a truggy? Thanks