I had this happen on a Mach 427 engine some years ago - but it was the main needle that was moving on its own. The o-rings had shrunk and hardened with time. New o-rings cured the trouble. I wouldn't doubt the same could happen to the idle mixture needle. Worth looking into IMO.

yup

orings dry out

Mito 7 is a great buggy engine, just a bit thirsty on juice. Anyone has mito 4 (both) can give their opinions?

NOVAROSSI MANTRA - INSIDE
One thing I had already noticed, the Mantra does not share the block and the carburetor as from MITO 4.

It could be square, but have the same block and carburetor from MITO 4.

Novarossi Mantra: Inside - ModellismoRC.net

NOVAROSSI MANTRA - INSIDE
One thing I had already noticed, the Mantra does not share the block and the carburetor as from MITO 4.

It could be square, but have the same block and carburetor from MITO 4.

Novarossi Mantra: Inside - ModellismoRC.net

Tame a P5XLT
 

What do you guys do to tame your P5xlt motors?

Over half a gallon through this engine so not yet fully run in. With a 2096 SS pipe this thing is insane 😂😂 Low & mid range is mental plus decent top end with lots of smoke still. Using the 7.5 venturi, 1.1 springs I think.

Any tips to make smoooother? I want to start practicing !

What manifold are you using, the 2096/41021 is pretty smooth to me.

Get rid of the 1.1mm springs for starters ....lol

That too lol, I use 2 .9's and 2 1.0's with all aluminum shoes.

Using the 2096/41029 combo... will try smaller clutch springs ;)

I'd also be using 6.5mm venturi and the 9901/41021 pipe/manifold on that engine in a buggy.

Thanks Dan, I'll order the 9901 pipe this weekend. Heard it's smoother with better run times. My current setup absolutely rips ☺

Why would you order a pipe that will add more bottom and lose top? The 2096 is the right pipe. Maybe Monty can add some info. I have a 9886 on mine but it is a older pipe with a square header.

41033 manifold, if need to tame it again, use steel flywheel but cheapest solution is change softer spring or carbon shoes

I recently got a Virtus .21 offroad engine and today I finished the first part of the break in, but before I take it to the track can anyone recomend me a pipe and header for this engine.
My local track is a medium/small track and it is a fast track so run time is key to success.
Also if I am not mistaken it is also advise to remove one of head shims once break in is done.
Thanks for all the help.