Setting it with the motor running on the box using the pinch method is the best way to get the right idle gap for your motor and set up. Setting it maunually with a drill bit etc is ok, but it may still be not quite right. Doing it dynamically with the motor running is better IMO

+1 IMO

Hi guys i just got my go 21 7port came with an extra shim and turbo button on the crank case it's says B21 , it's not the Gx type can anyone tell me what's this extra shim for ? and how is this engine is it good or not.Any known issues with this engine

thanks

that sounds like a gen 4 go-tec.the shim is for break in. do you have 2 head buttons? if so use the turbo with a os-p3 glow plug. You will need to take apart and seal the carb base and backplate. get yourself some nitrile seals for the carb needles,those will go fast and a new conrod for after break in. the engine was based off of novarossi's and it is a great engine. I have 12 gallons on one of mine. when you take it apart clean the whole inside with nitro cleaner then reoil with some after run oil. you should be good to go. seeing a pic would help. On all of my earlier go-tecs I use the 5.5 carb it has the red go logo on the front of it.

Hi Africa, send us some pics showing the top of the cooling head (and the graphics on it), then we can determine what Gen motor you have, and what model carb and crank it has fitted. This is important in terms of rod replacement and tuning etc.
All the motors from Gen 4 onwards are strong, but can be a little tricky to tune if you don't know what low speed needle you have fitted.
We will sort you out and get you on the right track - no worries

Well I broke in my GX-5R today and it was a breeze. It does have some grunt to it and I can't wait to get my RC8T CE to the track next weekend. I was racing a REVO with the 3.3. So this is a whole new world to me and I think I'll like it. The handling of a truggy this motor are going to be fun. Now I'm going to have to see who else is running these motors.

@ Bigmatt & Grizz1 Thanks ok here are pics of the engine,yes came with 2 head buttons, have not fired it up yet as want to flush it out and get a bit more info on it ,where can i get nitrile from?

Looks like a 4 to me.

What you have there is indeed a Gen 4 7 Port motor (indicated by the simple GO and .21 only on the cylinder head, and the alloy end cap on the carb where the HSN screws in).
There is a 99.9 % chance this motor will be fitted with the long taper LSN.
Being the older Gen 4 model it will also be very tight to break in. It will require serious heating before turning over, and unlike the new GX motors, will take a lot longer (approx 2 gallons) to loose it's pinch. These motors where notoriously tight when new, but with a proper break in you will have a motor that will last and last.

Go to the GO Racing NZ web site at www.go-racing.co.nz and click on Tech Tips in the left hand menu bar. There is a detailed break in guide, plus a detailed tuning guide for the long needle carbs there.
With the Gen 4 motor being tighter, you will need to do a lot more tanks than stated there before it free's up enough to race tune, but the basic method is the same. You will most likely need to undo the glow plug a half turn to ease the compression for the first half dozen start ups too. Nip it back up as soon as she fires.
You will need to change the rod after break in (at 1.5 to 2 gallons - no later) because of the punishment it will take during the tight run in on this motor.
This is going to be a slight problem, as the Gen 4 motors had a smaller crank pin size, and the GO factory now does not make a rod to fit the smaller pin size - soooo you will need to replace the original crank with a new GX crank and 21-0600 Pro con rod. The 21-0600 is now the only rod available for all GO Pro engines. There is a 21-0800 RTR rod out there, but it now has the bigger bushing as well, plus you don't want to run the 21-0800 as it is an older and inferior design to the new and improved 21-0600 Pro Series rod.
Nitrile O rings are a must too, and are available from GO distributors depending where you are located.
If you have any concerns please PM me for more details.

Thanks don't mean to sound nasty but it Sounds like i bought a crap engine I did a rough estimate of how much it's going to cost and its like £100.00 to get this stuff i paid £100 for this thing now another £100.00 ;( ........... Not Happy

Not really a crap engine - just an older model that has been superceded over the last 2 to 2.5 years. I started racing with a Gen 4 7 Port in my buggy, and it was a very strong motor in it's day. The new GX Series are a Gen 5.5 model, so lots of things have been addressed over that time and improvements made like any other brand out there.
To be brutally honest - I would re-sell the Gen 4 and get a new GX-7R. Will cost you less than upgrading the old motor providing you can sell it on, plus you won't have that looooooong run-in time of the Gen 4

Excuse me guys, but due to some bad evenements came in my life this spring, i had to sell all my racing vehicule. I had a GX-5R with the GO tune pipe in a D8 truggy, but i have only break-in this engine and don't have any chace to race it.
But now, i'am to buy another buggy (a Jammin X2) and i want to put another GO in it, but i don't know if i'll take a 5 or 7 ports.

I have an Ofna 086 tune pipe here with a short conical manifold, and i want to know if i'am better with the GX-5R or the GX-7R.

Thank's for your help

David

? for all you guys that are in the US Where is the best place to purchase a new go gx5r and a pipe.

I'm looking for a hobbyshop not personal seller.

how much is 100pounds in ausie dollars ?

I agree with grizz, try sell it on and get a GX.

There are guy's out there willing to rebuild with up grade parts (crank/Rod) after break in. So try sell it on.

[QUOTE=Flanno;7625910]how much is 100pounds in ausie dollars ?

£100 = $180 AUD