If you don't have the correct puller or installer, the oven trick is the best way. here are the sizes you need

Rear...14x25.4x6
Front....7x19x6

Thanks, but are you sure those are the ones for my GO .21 5pt ?
The reason I ask is because I read a review on those same bearings and a guy said he bought them for his GO engine and they did not fit/work properly and I don't want to make the same mistake.
Thanks again.

If anybody knows what size bearings the Go Tech engines needs, it is Mugenb46. He has been modding Go Tech engines for a quite sometime now.

+1

I was breaking in my 3-port sport today...first break in I have ever done. I was using a combination of the heat cycle method and the instructions that came with the engine. Unfortunately, the engine was much too cool - around 160 degrees. I have only idled my way through three tanks of gas so far, no real throttle yet, and no driving it around on the ground. LSN was flush, HSN was about 2 turns out from flush which is probably what contributed to the ultra-low temps (That and no foil around the head).

Have I already screwed my engine forever, or if I make sure that the rest of the break in takes place around 220-240 degrees or so will that help? I still have about 10 tanks to run through it as I slowly lean the engine out to make power.

I guess I learned my lesson (and found the break-in instructions on page 78 of this thread). Just wanted some input from people who have done this a lot! At least it wasn't some $400 mill, I guess.

Thanks!

Alright then, thanks guys
I guess my engine will get ceramics soon !

It should be fine; If anything you may wanna replace the rod after about a gallon of fuel, which is not a bad idea to do on any engine after break in. The good thing about the Go's is the rods are only 18-20 bucks.

I just wanted to get on here and let every go engine user know my expeirence with (22racer) Rex. I bought a worn out go .21 5 pt. from a fellow member and was having problems with it. I sent it to Rex and he put a new rod new boot and pinched it for me. This motor has been spot on. I am so happy with this engine now, it runs like a new engine, and is consitant. I would recommend his services to anyone that needs a pinch. Thanks Rex!

what crank pin diameter of new go crank?

I will try to get that for you tomorrow r1

thanks a ton...

Crank pin diam. .196" or 4.98mm

k thanks

Can anyone send me a link for the rod on a 3 port r? All I can find is the 3 port sport rod on amain. Are they interchangeable?

Yes, the 3 port sport is the same rod. Any Go engine uses the same rod.

Thanks for the kind words Hobdog!

Rex