Was going to ask the same question i just received mine and found .30 in total and not .50

Yes, there are 2 shims, 0.1 and 0.2. Just take away the 0.2. Those are head shims not head clearance.

Be sure the head clearance should be 0.35~0.4 by soldiering test.
With 0.1 shim, the head clearance about 0.35
With 0.2 shim, the head clearance about 0.42
With 0.3 (Both 0.1 and 0.2) shims, he head clearance about 0.45. It's for 20% fuel.
With RP6 plug, it better for large track.
With P5, its better for small track with more pick up.

I asked OS on facebook if i need to remove any shims to run 16% since the manual states 20%. Thier reply wa sas follows

"The change isn't much, but you can take out the .10 shim and that may help a little bit."

hey guys! nitro season is afoot and im looking to find a decent setup for this motor. i only had 5-6 club races on it last year after break in, and while it was fast, it was a little fussy to dial in. its still on the rich side as our track is quite small with lots of slow corners. so just a lot of blipping between them ect.
typical parking lot.

Our track is at sea level. i expect 18-28C which i know is quite a range in temps, but ill be running on 20% fuel likely.
should i stick to the RP6 plug that comes stock or should i consider a colder plug? I remember very good results with my old os12tr going to the cold plug on 20%
the guys im competing against have murnans which i know are very fast but shouldnt this have kinda similar rip?

Im also curious if the sc1070 is an ideal pipe for this motor on a small track? or should i consider a different setup?

sadly, no perm facility and i can only make it out every two weeks in the outdoor season. any help i can get is much appreciated!

Has anyone run any Novarossi pipes with the OS Speed .12 Spec 3?

If so what good results were achieved and with which pipes?

Thanks!

Does anyone have a connecting rod for speed .12 xz speed spec 3 for sale

Hello, does anyone know if the piston/sleeve and connecting rod from T1201 fit to 12xz spec3? For example https://www.worldchampionproducts.co...-2a403010.html
I have a Mag tuned Os speed spec 3 in which the connecting rod broke and the piston was damaged and I am thinking of resuscitating it.

This is definently the boss, anyone run the engine yet?