I have used a front bearing from a nova n21r in my GXII and worked fine. Actually used a conrod also. Engine runs great!

A-Main have got the bearing size wrong.

This subject came up couple of pages back, either on here or the other GO forum.

Thanks guys!!

Can someone tell me the best temperature when you break in a new engine ?
I speak for the new GO engine, the GO GXII-5RHO.
It uses the 8.0 venturi out of the box. Should I put the 6.5 venturi ?
Or break in the engine with the 8.0 and then change it to 6.5 ?

Preheat engine to 210 to 220. Start engine and keep temps over 220. Anywhere fron 210 to 250 is safe. Just leave the 8mm in for now.

I ran the first 4 tanks through it last night, went great, not a single flameout or hiccup. I had to preheat to about 240 before it would turn over enough to start, and in the past heating up to 250 if needed has not hurt anything.

Agreed on running temp, but I try to keep it above 220 and closer to 240 during breakin to be as gentle as possible on the conrod. I either use tinfoil or my Comp Heat to cover the cooling head to keep as much heat in it as possible while running it really rich on the first several tanks.

Also agreed on 8mm venturi, easier to tune during rich breakin. Try racing the 8mm restrictor before you switch to the 6.5, I have started running it all the time that way and love it on the old 2needle carb, we'll see how it works out with this 3needle. Seems mean as always so far!

+1 on all the above guys. That pretty much the temp range and set up we use on the run-in bench for all our customers motors (220 - 240 F).
After 10 - 12 tanks on the bench the motors are freeing up nicely and on inspection the rod is still a snug fit - no play. However we still recommend changing the rod around the 1.5 - 2.0 gal mark when the pinch has dissapated more, just as a peace of mind precaution. Despite the heating and TLC, the rod still takes a hammering over those first few tanks. Their inexpensive enough, so why take the risk .

Does anyone know what is the minimum wear on the crank pin? If not, does anyone have a crank handy and can measure what theirs is at? Thanks!

The crankpin new will measure around .196-.1965. I consider .003 wear to be max so around .193 would be your low side.

Rex

Thanks, Rex!

a mains bearing sizes are in correct.

all front bearings are 19x7x6

unless nova changed their crank case which i doubt.

So is anyone running the gt5? I am trying to decide between a new one of those or a used gx7 that was worked over by rb mods with 7 tanks through it for less than $100. That one fits my budget better of course. Which ever one I get will go on my 11 spec 808. Which would y'all go with?

Depends on what it is going in, I do know the Rb mod 7 port will not have a ton of bottom end.

Rex

I saw an RB mods 7 port run just last week and it was almost pulling wheel stands. Seemed to have heaps of bottom end but thats just my opinion.

Personally I have to say if you are in the usa Rick Brake would be one of my top choices in engine mods. He really knows wht he is doing :-)

Cheers m

Its going in an xray 808'11 spec buggy. Looking for versatility for bashing, long and short tracks.I have sirio 2013, 2058 pipes.