Maybe give the R2106 a go, untill now racers who are using them seems to be satisfied.

Thanks for the insight. I'm starting to piece together all the parts needed.

About break-in.... in the old days broke-in all my engines by 'fourstroking' two/three tanks with cool off between them on the starter and then to the track very very rich (no 2nd gear shift and no complete clearing) and leaning slowly up to 85-90C final temp. That worked me well in the past. There's a new method? or this is a new way? TIA

There are 1001 ways to break in an engine and if you filter the important things you will see all are basically the same.

- let it idle (although that is a discussion topic on itself)
- stat rich
- lean out in small steps
- take the time and enough fuel

And one tip from my side. When you think it is broken in, the next time you fire it up it is wise to take it easy again for a short time. Over that time the piston did grow a tiny bit.

Roelof Thanks for confirming what I supposed. Been out of this for 20 years and maybe what was fine then isn't ok nowadays but seems the same recipe that I've used to break-in the most stubborn b*tches in the past (Sirios, Ninjas and such) with a lwell earned reputation of creating doom on starter boxes

Took a quick grasp on the manual of OS Engines and they mention something that found many time ago and is an overly lean low-end needle masked by the overly rich high speed needle and they talk about this. Looks like I'll like a lot those Japanese mills (the old R21 VZ piqued my curiosity...).

Also for an easier start(in the first gallon), pre-heat your engine.

It is a common mistake (for sur among bashers) that people correct a wrong tuned LSN with the HSN. And then there is also a famous JQ video telling an OS carb needs an idle gap of 0.5mm and then the idle can be perfectly set by the LSN. Yep, plenty of bashing wannabe youtubers are advising this, so if you want a bad LSN you have to follow that. And I have seen this from a close distance with a guy who could not get the LSN right but refused to change the idle gap....

Regarding the break in, for sure with todays low oil content fuels it is wise to add some extra drops of castor oil or get a liter RTR fuel to give that extra lubrication with the 1st part of the break in. Beside that is has become a very common use of even adding about 1% extra oil when racing.

And yes, since a decade there is a 1002 method of braking in and that is the oilbath. It is no full break in but a very well by a machine controlled way to get the engine done for about 60 to 80%. There are plenty of topics on this forum about that.

Ordered some bits from Rody for preparing next ENS season, leaving the 2106 for X'mas, prefeer to know how performs that blue headed R21 (still remember how sweet was the 21VZ). Updates short (hoping).

Just received those two beauties (along some other bits) from Chez Rody. Euro 2 is a well known with a lot of info, but the R21 Version II is a complete unknown and almost nothing is out about this mill.

My bet is about being a 5 port sleeve and for what it seems, nothing exotic on it (not needed in reality) but looking forward to break-in and ride it for practice and club running.

The v1 5 port is a decent engine. No true high performance but also not bad as well. The V2 is also on my list to see what it is and make it to a faster one. Timing wise I do not think there are changes.