The P5XS is an older model, (production year 2007) and uses a standard plug. P5XLT is a 2009 production year engine with a turbo head button and a few improvements over the older version. They share the same R7 conrod and a few other features but the newer version is better depending on who you ask. Don't get me wrong, my P5XS still gets the job done. All the P5 based Novarossi engines kick butt! I copied the discription from Amainhobbies below.

This is the Novarossi S21P5XLT .21 class turbo plug nitro race engine. This engine is the revised version of the notorious Novarossi P5 and has a slightly more aggressive power band compared to the P5XL. This engine includes a R7 conrod made from super light aluminum and designed to create the least amount of turbulence inside the engine. The sleeve has 5 transfer ports to create a linear power output and to keep fuel consumption low. The crankshaft is manufactured with a larger bore intake to increase the mixture flow, and has a special shape to optimize gas-flow in the engine. The rear bearing has a outer diameter of 25.80mm and has been used in order to avoid ring distortion and to increase lifespan. The two needle, slide valve, nylon body carburetor features a standard design that allows the use of interchangeable venturi's to tune for any track condition.

I was wandering if any of you know what nova cranks will work in the novarossi 21 plus 5k? My buddy needs a crank for his . Thanks!!

Ran my toro for the first time this weekend (with an 053 pipe). The thing absolutely ripped at all points of the throttle curve. Barely touched the needles all weekend. Very happy camper right now.

Guys,

I'm thinking of using the Plus 21-4 2009 TUNED Edition for the Xray XT8 truggy or the Mugen MBX6T. I have an old, but in great shape Jammin JP-2 Pipe with header I'd like to use. Any issues?

Thanks...

i would get a 9901 or 9853.for this combo

If it is a 5K; you need a 14.5mm crank.

Either of these p/n's: 15011; 15012

sent you a PM

hi all, i am running a stock +4 with an extra .01 mm shim in the head with turbo c5 nova plugs and recently started fouling glow plugs after every heat (8 minute run), the plugs are not compressed, they appear fine, just do not glow.
I have tried running the c6 turbo plug but the motor will not run without the glow warmer on the plug.

any help will be greatly appreciaed

BTW i am running 30 % nitro never had a prob with the fuel

Why the extra .01mm shim? Not needed. The +4 will run jut fine on 30% with the stock shimming. Could be the culprit.

Edit; also try the Odonnell Plugs. They are awesome in the Novas. 97T

That is exactly how I feel the 9901ss performs or doesn't perform , I did however use a 41005 header on the pipe and it definitely helped but the 98543ss is much less restrictive and offers way better performance . IMO

The differences between the two are one has a head that says p5xs and one says p5xl , the turbo is more of a personal preference thing

Thanks for the feedback...

Now to look for a 9853SS, which header?

9853ss/41005 is awesome and if you think you need more low end punch try the 41021

I just got a P5X S21 from a friend of mine and the motor is great I have run the Re10 pipe on it and it felt pretty strong what other pipe would you recommend.

thanx for the reply mate, from new the motor had a far more stable idle with the extra shim, but will give it a shot without it.