In the USA, looking for a rod for an older Go engine. Label on the box says R217PT-P320SG. I've looked around on the web with no luck.

It looks like one of the previous GO models, this has the part number you need.

http://www.glueck-modellbau.de/data/..._0000015_1.pdf

If 30 % is all you can get just use that.
I will be a little harder on the rod and wrist pin that's all.
A .2mm shim is what you are after. I don't know what shim the werks motors run.
The shim will help lower the compression, especially with the 30 %

read your break in on go web site saw this in the break in part "HSN - 1.25 turns in from flush. LSN - 0.75 turns out from flush.
The motor will start and run at these initial settings."

then towards the bottom of the page it says

"If you have completely "lost" the tune on your motor, or are tuning from scratch after re assembly of the carburettor etc, return the needles and idle air gap to the following base settings:

2 needle carb
HSN (High Speed Needle) – Flush
LSN (Low Speed Needle) – Flush
IDLE AIR GAP - .5mm to .7mm

so the break in is a whole 1.25 turns leaner?

No - the run in guide has been updated, and is now specific to the 3needle carb only,
which is the only carb the motors now come out with from the factory.
The current A-main stock is all old stock with the 2 needle carbs.

If you look at the tuning guide you will see the tuning figures for the 3 needle carb as well. These are the figures you need to be comparing. You are looking at around a quater to half a turn max richer for run-in then for race tune off the top of my head.

The GXII-5RHO 2 needle for run in - HSN flush and LSN around .75 turns in from flush.

Race tune will see top end in about 2 - 3 hours only from flush, with bottom end in about 1 - 1.25 turns in from flush.

heres the final photo's of the JQ with the GO MM MG66...

pics arent the best as it was taken in the kitchen after dark..

Gotta question for ya'll. I'm just curious to see what head shims are being run with 30% and 97T plugs for the GX3, GX5 and GX7. 2072 pipes are on all motors. Different strokes for different folks so I wanna hear if everybodies on the same page and what results you've had with a particular combination.
Thanks for any info!

We mostly ran the stock .5mm head shim with the GX Series on 30%.
If you want a tad more bottom end snap and a little more economy you can drop to .4mm of shims on 30% no problem (running the 97T).
This applies to all the GX Series, as well as the MG66.

We have yet to experiment with less shims on the GXII. It's pretty good ex factory so far

holy tight motor bat man . had to losent the plug alittle the first start seems like it should get my truggy around pretty good

Ouch

No heat gun available

yea i heated it to 210-215 it was the first time i used my box since last year and i think the batts arent what they use to be, it was fine though i heard of other people doing it. i coulda prolly got it but wanted to get it going after the 3rd time geting stuck at tdc i lossend it like a quarter turn and fired rite up then i just tighten it

Oh that's good news, glad ya heated her up first

So just for referance incase anybody else is wondering, 1-silver shim (0.3mm) and X2 brass (0.1mm) shim for a total of 0.5mm, correct? People can get confused when it comes to shimming the head. Heck I do occasionally
Also, how's the differance when going .4mm? Is it that noticeable on the bottom end and how much does it increase the fuel milage would you estimate?

The differences are only minor. Just a little sharper on the bottom, and the run time increase is negligible.
Best to just experiment for yourself i would say.
Raising the compression makes the idle a little more erratic and narrows the tuning window slightly, but the GX motors did run strong with the .4 mm shim stack