I just got a tunes .21 and everyone I race with use the GRP plugs .

Cheers Bungy!!!

no thats funny

yes you can run any plugs you want to as long as they seal up good and dont spit fuel out from around the glowplug :nod::nod::nod::nod::nod::nod:

i have found the grp plugs very good and extremly reliable :nod: i bought the 5 pack grp plugs and have not even used them yet i am still on the original plug raced the nationals with it and also ran the same plug to break the engine in and still is going strong i didnt replace it for the nationals as i was worried it may chenge the tune as it was a new plug but while there working why replace them :)

I'm having a problem tuning the top end of the GRP Tuned. The thing takes off like a rocket, but it gets to what feels like mid range and never pulls out the high end. I tried adjusting the HSN but the temps seems to get too high, over 230. Any suggestions?

Try taking the motor back to factory needle settings
HSN=3.5 turns out from bottom
LSN=6.25 turns out from bottom
IDLE SCREW= 1-1.5 mm depending on where the lsn is set
Leave the top end alone and lean the lsn small hour turns at a time till you have good smoke and good punch off the bottom. If you need a little more on top just lean the hsn a small turn or 2. Keep in mind if you tune it and run up and down the street 2 times you haven't given the motor a chance to balance out. Meaning before you decide you need to crack the screws anymore give it a chance to catch up 10-15 laps on the track or 20 passes up and down the street. Its really easy to get these motors to lean because it takes a minute for the needle turn to really grab hold. Other than that check the usual suspects. Fuel tank filter fuel line carb boot and o-rings on the carb.

this is exactly what was happening with me, i went to a p4 and solve all my problems, idk if this will help u tho

Well I switched to a P3, I usually run a P7, but I was having a problem starting it. I'm taking it to the track tomorrow, so I'll set it back to factory and try ya'll suggestion. I usually ran it for like 5 mins per adjustment, guess I'll go longer. :weird:

Drake told me the P3 plug is too hot and to use the P4 instead.

+1 all I run:nod:

well definitely 5 minutes is long enough for sure ....was just saying alot of people i see at track ...crank it idle it for a minute gun it to the moon a few times and they are ready to start leanin er out ....really you cant tune a nitro motor proper unless the chassis and clutch are heat soaked ....it just causes you to lean a motor up to much ...then when your in your race it starts running funny ....:)

most people run hot plugs because they idle better and the tuning window is larger ..when in all reality a colder or medium plug will give better perfomance ...they just dont idle as good and the window on the tune is smaller ....i just run plugs to the ambient temp ...if its 100 degrees i will run a cold plug ...if its 30 degrees i might run a hot plug ....mostly im running medium plugs though ...but yeh i agree with ya on that if i was running os plugs i would run a p4-p6

Hey guys Ive been braking in my tuned .21 today. This is the first high end engine I have broke in and tuned. I managed to idle 3 tanks through on the work bench. And man I understand what a tight pinch means now. I used the heat gun quite a bit. I tell ya though it took forever to burn up a tank, like 30 plus minutes. After the bench I took it to the street for 2 tanks doing fairly slow passes and leaning the hsn just a couple hours or so. These tanks took like 30 min to burn up too. I read on the threads that these go anywhere from 10 to 12 a tank. Is this just how the breakin is because your not on the throttle consistantly? I just thought it was a big difference from 10 to 12 minutes. My temps were around 160 to 180ish.

as long as you have good smoke you are fine ...tyr not leaning the hsn as much as you would with like an os motor ....you may end up to lean on top inhmo ...i really didnt lean the top to much ...maybe a little on break in ...leaned more on the low speed needle on break in ...but either needle dont lean to much ...are you using foil or a sock on the head? it helps keep temps in and needle settings still rich for break in ....on the long run times ...you aer getting good traction cuz your on the street ...plus your hopefully just blip blip bliping it around ...so i can see that mine were the same way ....just dont get it to lean on the top .....after its got about a 1500cc of fuel on it ...take it back to stock settings on the needles and re-tune it with out the head covered ....:nod:

Thanks for the tips Zixxer. Ya I am just blippin it around and I did not use a cover. Never heard of that....Its just kinda hard to keep patient while breaking these things in, but well worth it in the long run I'm sure. Thanks again

Hey guys awesome thread with a ton of info.

Question: is the tuned .28 overkill in a truggy. Should I order a second .21 instead.

Everyone around me keeps pushing me to go with the jk's in both.

Also pipe question: everyone says that the grp pipes get better mileage but at the price for a dynamite, ofna or other brand 53 are half the price?

Any one better than the other..

Thanks guys