if u are to lean on the bottom the motor will make more heat. also lean on the bottom and fat on top the motor will take longer to clear out, i run as much fuel as i can on the bottom and tweak the high to get it were i want it.

my advice is go Novarossi top quality ,reliable ,more power than what you would ever need,and long life span.

shim the off roads at about .8-.9 use a novarossi C6TC OR C6T7 depending on the temp at the time or even the oddonell plugs work well .

Your engine will flame out depending on your shiming and thats 100% sure ,also use quality fuel.

we ran a test on the novas here in Australia and ran all sorts of fuel .The ones that worked best were the mecano,runner time and sidewinder no problems with tuning whatsoever and no flame outs.

some of the other fuels didnt tune or work at all.


just my two cents worth

I got 1 question guys.

(OS P3) plugs help reduce the compression ratio in engines that use long plugs. Is it good for the engine?

IT FUNNY HOW PEPOLE HAVE SO MANY WAYS THAY THINK A MOTOR SHOULD BE TUNED

I just got a GRP .28 and having read this thread people don't seem as thrilled with their engines as some of the threads for the other motors I have been looking at (vs. the Trinity thread for example where everybody seems to be just going nuts how great their mill is) and the bulk of the discussion seems to be people disagreeing on how to keep this engine tuned. I got the GRP based on the way it has performed for the pros, the great build quality and what I hoped would be ease of tuning. I guess just looking for some reassurance that I made the right call. I was already questioning my decision of going .28 vs .21 - and after reading this I'm now questioning my decision of going GRP (instead of RB or Extech). Any positive feedback would be greatly appreciated. Would prefer to know what people think before I crack the box open. Thanks!

I had the same concern you did about making the wrong decision.

I know one thing I am liking mine, still not done breaking it in; so my opinion is not fully tested.

I was fortunate to have found a super deal on a vspec to put in a new buggy. When my GRP was new I could not hardly turn it over by hand, tons of pinch & compression. The new Vspec was a lot easier to turn over. Looking for longevity, I went with GRP. The GRP is by far finer craftsmanship. I think tuning is a learning experience with this motor. It seems to me that with this motor if you touch one needle the other needs some attention. And only adjust in SMALL increments. So far to me it's not a pain to tune, It's just different changing the LSN.

Also, about the flame out, I have found I am too rich on the HSN when it starts doing that.

Well, I haven't run a Sirio based motor in a while (and yes, GRP's are Sirio based) but when I did the carbs were a little iffy. Some were good and some were junk. Try it out. If you have trouble getting it tuned in just drop an OS or Nova carb on it and problem solved. If you don't have one just ask around the track. Someone is bound to have an old one laying around for free or cheap.

DONT WORRY,,,,,,,,,, I VE RAN ALLMOST EVERY MOTOR THERE IS AND THE GRP IS ONE OF MY TOP THREE ... MOST OF THE PEPOLE HAVING PROBLEMS ARE MOST LIKLEY NEWER TO TUNING MOTORS .

THAT WOULD BE MY GUESS

TOP THREE

NOVA P 5

GRP

RB S 3

STOP YELLING YOUR GIVING ME A HEADACH.LOL

Where did you get that knowlegde? GRP's are Sirio based??? Can you explain and enlighten us?

I agree but your signature is screaming too.

Also, I'm hearing that the pipe that comes with the promo kit may not be the best suited for the job. I have an 053 and an 0801 pipe. Would either of these run any better or should I just get the JP-4 that most people who don't use the promo pipe seem to be running?

I LiKe CaPs ,, ThE pIpE ThAt CoMEs WiTh thE Kit WoRkS fInE

I ran the JP 3 on mine before getting the GRP pipe. The motor ran good with the JP pipe. But I"m leaving my trust in the manufacture and running the GRP pipe. This engine is pretty special. A gallon and a half and still metal pinch with no glow plug in it. I think this will be a multi gallon engine. One thing is for sure, I've never had an engine run this low in temp. and produce so much power at that temp. Just use the bottom end needle on the lean side and it sings!!!!

No worries! If you have experience tuning engines and do your research, You will fall in love with this motor. Switched out to a P3 plug and no more flame outs. I ran a 10 minute main and came off at 183 in 95-100 degree weather...SoCal.
Again though...everyone has their own opinions.
Enjoy!