All I can really add from experience about plugs is do NOT put an OS plug in a novarossi. You will for sure screw it up. McCoys are OK though if you cannot get novas...

I also advise using the plug recommended my the manufacturer. After all they designed the motors and the plugs and they for sure will work together.

My guess would be that plugs that work in Novarossi's and RB's should also work in GRP's, since they are all manufactured by novarossi. But dont hold that against me if im wrong.

Can someone tell me the factory needle settings of this motor?

My .21 was 3 1/4 out high, 4 out low.

Having had my .21 come set from 2 turns out from factory I had to get the settings off of another engine in order to get it running, as quite simply it was set way too lean on the top and too rich on the bottom.

Consequently the settings I used where:
4 Turns - HSN
6 1/2 - LSN (Carb Barrel Open)

They are on the rich side, especially the bottom but better that than too lean like mine was...

I no longer have the Ninja .21 and Ninja .28 engines....But when I ran the .21 motor these were my settings:

I run 30% Maxy's fuel, Ninja #6 plug (#5 plug in cooler weather), stock 7mm venturi, MSR1005 pipe & header and added one thin copper shim (0.004") to increase the deck height. LSN = 5.5 turns out, HSN = 4 turns out. When looking at the needles both are at the 1 o'clock position. Motor never ran over 250* once broke in. During breakin the motor ran at 280-290*.

I still have a 5-pack of Ninja #5 plugs. If anyone is interested email me at [email protected]

Best regards,

Blah blah blah I just bought a new engine, I looked at the GRP, held it's pretty orange box, looked at Mario Rossi's smiling mug, dreamed of being as fast as Drake, and realized I was about to be another victim of marketing hype.

Not saying it won't be a good engine, I'm just saying it's not gonna be kryptonite to the all the little supermen we already have.

Its been "Horizon Hobby" pumping the marketing hype up! They do that with all there stuff.

TBH guys I'd be very interested if where yo've got the needles set once runin too ??

Mines @

HSN 3 3/4 out
LSN 5 1/2 out (BARREL OPEN)

To be honest I still get the feeling the tops rich too, temps low and isn't topping out as i'd like yet. But she runs strong and I'm still learning the motor. I haven't had time to just test run it yet either, I'm always having to try and tune it in on race day

I run on a fairly open track with long straight, using 30% BYRON Gen2

Thanks Guys

I got to break in 2 GRP 21's Friday and race one of them Saturday. (One was in a truggy, the other in a buggy) Good engine for sure. Break in was effortless (no blown plugs, but the needles were too lean from the factory). Not one flame out on either motor and they both ran great all day Saturday. Temping 240-260 after 10 minute qualifiers (I expect these to go up a bit until the pinch is gone..much like my Ninja did). So far, I really like the GRP...very smooth with more top end (at least it seems like it so far) then the Ninja Bo1A. This motor is definately different then the Bo1A as well...the crank is epoxied and the sleeve looks a little different (from memory of my B01A), and the piston has a domed top (like a nova 21-5k). 9 minutes per tank in truggy (on a pretty open track with a lot of WOT pulls) - I know I got 9 minutes as I tried stretching a 10 minute qual and ran out of fuel, and has plenty of power, but I think the strongest features of this mill will be the smooth powerband, ease of tuning, and long run times. Should be able to do 10 minute pit stops once she is broken in (depending on track of course). It is definately (less finicky they my 21-5kt). Running 53 pipe, 30% titlted green and OD97T plug (the only plug I ran in my ninja, and my current choice for my 21-5kt as well). OD plugs have never let me down

Since no one seems to really know what plugs are similar/compatible, I'll figure this out for us. First close up look is a Novarossi vs GRP. Next I'll get a hold of an OS, then the ODOnl plug and we will see.

DO NOT use Nova plugs in your GRP! Strike #1.... RB and Nova are exactly the same taper so don't use those in your GRP either.

gtsum---thanx for the info. I'm in the market for an engine for my truggy. I keep looking at the GRP's mostly because they are the freshest design. I have been hoping to read about some feedback from the racers.

Thanx

the new gold head GRP is internally the same as the MR tuned Ninja's....the silver headed GRP's are the same as the regular Ninja's inside........ The cases are different, but the sleeves,pistons and cranks are identical........ Yes the Ninja also had a domed piston as well !

they are just a very nice running .21, with the best fit,finish and bling in the industry... They definitely aren't superman, but they are at least IMHO the fanciest show in town !

No offense, but pictures and basing it off of pictures can be inaccurate becuase of angle, distance, etc...

I would like to see the numbers on a set of calipers, actual measurements...

Dude, run what you want to. If it floats your boat to run OS plugs, do so. It you bought a GRP engine, you should run GRP or Ninja plugs that fit correctly, end of story.