Regarding gx2 p/s/c set 21-2205x to put in old gx5r crankcase, wher can i get the .5mm shim to suit the crankcase

You say that, but when I tried the GX2 crankshaft in the GX5-R, I found that the rod would rub on the crankcase, as there was no longer enough tolerance machined into the groove for the rod to pass cleanly.

Furthermore, simply measuring one of those gold tini coated GX5-R crankshafts vs a GXII crankshaft you can measure a difference on the crank pin, 0.02mm.
(Yes, brand new crankshafts)

I think the reason the rod rubs on the crankcase is that since the pin is thicker, this puts the rod further out towards the crankcase.

So I don't think you can say they are interchangeable.

Any engine designed by a sane engineer should have tolerances that can handle a 20 micrometer difference. I have a digital caliper, and the tolerances I've seen are always in the 100-200 micrometer range, because otherwise heat expansion alone would make the engine parts bind-up.

If the conrod only *rubs* on the crankcase, as opposed to clanging against the side and getting jammed, then you should be able to file-down the area of the crankcase where more clearance is needed. This is a hobby after all, some end-user customization is always required.

Agreed, always recheck installation. Some parts are interchangeable, just an alternative for cheaper price

What you have stated makes no sense.
The external diameter of the 21-0600 rod will not change because the crank pin is .02mm wider - which I believe is totally incorrect anyway.
As long as the pin sits snuggly in the rod end bushing - how can it make a difference ? The only way to alter the arc of the rod end is to increase the rod ends outer diameter, or move the location of the crank pin on the crank.

The 21-0600 rod has been used from the GX Series right through to present day, and the internal diameter of the big end bushing on that 21-0600 rod has not changed over that time......... so why would the crank pin size change ??

I think you either need to get a more accurate micrometer, learn how to use it properly, or stop playing with yourself.
You have a very well known reputation on here that preceeds your posts on multiple forums.
It seems all you do is continually (and annoyingly) pop up and contradict people and look for arguements. You really do need to get outside a little more.
Feel free to reply if you must, but you will be wasting your keystrokes as I won't be around to read it.

Guys - It's been fun talking with all you GO users over the last 7 + years, and I hope I've been of assistance to some of you over that time - but I just can't be bothered with individuals like our friend here anymore, so it's time to say adios from this forum (and RC Tech in general) for the Grizz.

Happy racing and take care out there

Have a nice day Sir!

U may need to add a shim at front bearing b4 collect, yes it will rub against crankcase, small matter. Just recheck everything b4 start ur engine

Does anyone know where I can get a Gx2 crank from in the US?

The "gold-colored" crank pin is probably narrower because it's Titanium-Nitride coated, so it won't wear down as much, so it doesn't need to be wider to start with to compensate for wear over the life of the engine.

The silicone filled gx2 / gx2plus crank not coated?

Udp 4 port combo with short manifold+nova 9886 pipe will smooth out the engine, but not good in fuel consumption

I don't know for sure if that information is correct. I had to remove the coating layer when replacing the bearings and installing a coated crank instead of a non-coated crank. It just didn't fit.

If it is coated (gold) , it will only be a VERY thin layer, i swap a 21-0907T to a gold coated gx series crank n it rubbed the crank case. So by adding a shim b4 collect will sort it out. i believe crank case is same n gold coated crank slightly norrower but will work.

My findings with 21-0907T crankshaft only lasted 4 gallon + n need replacement. Con rod don't wear much. Just my opinion. The stock bearing are great.

New GO .21 5 ports coming as evolution of PLUS.

As far as i know some improvements on timing and materials, and a more torquey feeling ...

Hopefully will have one in hand on some weeks from now ...

sorry double post ...