I just got a nice little surprise. Im four tanks into break-in and decide to pull the plug out for a closer look and to my surprise its a no.4 plug instead of the 6 that the manual says it comes with. Anyone else bought a .21 buggy promokit recently and got a hotter plug? Maybe they are shipping with the hotter plugs now?

Wow 5 gals on the same bearings, good to hear. Does the front leak AT ALL?

No, bottom of the motor is clean, I haven't take the fly wheel off for a closer inspection yet though.

almost 2.5 gallons on mine and front bearing took a crap during the a-main this past sunday..I just had it tore down on saturday for new seals on the needleds and a inspection. but it wasnt leaking so I didnt change it. oh well putting in front and rear ceramics now should be here thursday.

Does anyone know if the GRP plug is the same as the old Mugen Ninja plug? Both are made by GRP so I would think so. Everyone in on road is running the Ninja even in non GRP made motors due to its performance and longevity. Since the Ninja's will be getting scarce I would like to try the GRP's.

grp and grp ninja plugs are indentical, you can still find the ninja plugs on a few sites, much cheaper then the grp branded plugs, i know on the offroad engines i had much better luck with the os plugs, onroad could be different

Well I don't know about off road motors but most of the Novarossi sponsored onroad drivers were using Ninja plugs at the nats last week. An importer for another brand told me to run Ninja's. JP himself uses Ninja's. Must be something to it for on road. As for off road, maybe GRP Ninja's just aren't hot enough to work as well as a P3.

Jeez.. now i really wish i had purchased the grp motor from that site you guys linked me.. oh well i will for next one..

So i see that couple of you guys say use os plugs.. some say use grp plugs.. do i need to flip an coin???

just buy alot of grp plugs, i had about 3 out of 5 work, could have just been my luck, the os p3 made the engine alot more responsive and easier to tune, and will idle aslong as you want it to

I have not had any issues with the GRP #4 plug...

i have 3 OS p3 plugs left and 2 p4 plugs left.. so i wasnt sure if i should use the GRP since they made it for GRP motors.. and I used to run OS vspec eb mods.. so.. its a big swamp for me.

one thing i noticed about a a few of grp plugs was that they took a few times to work correctly, u would have to fire the engine up a few times before it would start acting correctly like the plug had to be broken in or something, i had a few that lasted a long time and i had a few that would just never work good, could just grab another grp plug and put it in and it would run good then just put the other one back in and it would do the same thing, if you allready have the os plugs it would be crazy to buy the grp ones, i did find the ninja grp 5's for around 8 dollars a piece when they are on sale, but i just would use the os plugs

lol yah i noticed grp plugs are expneisve everywhere else... I will just have to try and see whats up.

There's about 4 of us at my local club all using P4 plugs. Seem to be a little better than the P3 in this engine. They work fine.

I am a club racer looking at getting a new motor...been torn between the Ex tech and the GRP. Well a bud of mine has the GRP on a losi8 and got 12:13 on a tank. He is a consistant and competitive racer. He sold me on the GRP