You need a different crank shaft, 15803 (or cut off the extra piece that comes past the rod), and you need the 13802 back plate

And possibly different (lower) engine mounts...

awesome, thanks for the help, I will buy the backplate and just grind the crank.

Yup, it's just the last 4mm or so, after it steps down to smaller diameter. And like he said, lower motor mount, so the bump box will hit the flywheel.

awesome, again thank you very much.

Made this Nova plug guide in Fahrenheit. Hope it helps.

I pretty much use the CT06 in every temp

Guys what is the difference between the virtus.21 on road piston /sleeve /conrod(NVR08593) set VS the virtus. 21 off road one(NVR08594)?

Are they interchangeable?
Can I use the on road set ine the off road engine?

Please give me some help here!

They are interchangeable but you will not get a same engine when putting an onroad set in an offroad engine

The onroad has 9 ports, I believe the offroad not. But the most difference is the exhaust port, with an offroad the exhaust port is much lower to provide more torque.

Thanks Roelof!
So if the exhaust port is lower will the exhaust port in the on road sleeve match with the off road crankcase exhaust?

The crankcase is made to fit all, the difference in height of the exhaust will not be more than 0.5~1mm . If you put an onroad P/S set in an offroad engine it will make some more rpm but you will loose torque which is more important ro accelerate a 3kg car from corner to corner.

Understood!
Thank you very much!
I will try to find the off road set!

New full sets piston and sleeve using part # from exploded view 08594 & 08094.

Novarossi 08094 Reinforced CNC Piston/Sleeve 3,5cc On Road 7Ports Extra Long Stroke Rear Exhaust + Turbo Underhead + O'ring

https://www.ebay.com/itm/NOVAROSSI-0...oAAOSwMKxcOO2N

https://www.ebay.com/itm/Novarossi-C...IAAOSw9GhYkPc3

08594

For the price to rebuild might consider just buying the Rolling:
https://www.ebay.com/itm/Novarossi-Rolling/202632379080

I bought mine from this guy on ebay from Italy. Great sellser and ships super fast. I'm in NYC and would get engine in 2-3 days from date I purchased. I've bought two Rollings and one Mantra from him.

Thank you very much for your time in helping me!
As I can see the Rolling has the same p/s/r as the Virtus but different main bearing. Same dimensions 14.5x26x6 but normal one.
Do you know how the Rolling compare to the virtus in terms of performance? I assume the will be exactly the same.
I may buy the rolling and use the p/s/r in my virtus or just use it as is.
Thank you very much!!!

I can't compare as I've never ran Virtus and just got back into RC last summer. I personally really like the Rolling. I'm running it in truggy. I know reading through this thread a few other guys have it in truggy as well and are pleased with it. With the right tune and pipe combo I feel its great power from low to high. When i was first breaking in still running really rich I had enough to clear a decent sized triple and was good on back straight just a little fat lol.