i tried the od 97,,,,,,it would not seat in the head and it leaked fuel....

put back in the os and it was fine....

I know of 2 people in person who used the OD plugs as well as a bunch of people on here used them as well.

Cant hurt to try it and see if he can get it to work in his motor.

Maybe the OS plugs screwed up the threads enough for the ODonnel to not seal properly?

i am sure you are correct....i must have some how forgotten how to screw in a glow plug.....

sorry for my complete and utter incompetence.....

I see the keyboard cowboys have arrived...

i do not understand?????

i posted my experience, you said and i paraphrase, you are a dummy, and know nothing.....i simply bowed to your superior knowledge.......

Sure

IMHO the P3 is the best plug for the MRT GRP .21. However, once you use a P3 you need to stick with it as any change to the thread pattern on the head will make it will be difficult for another plug to seal properly. I think this is what was meant on an earlier post.

There is the answer, once you use the P3 plug you need to stick with the P3.. as for any other plug. It seems that the GRP head is a little finicky with plug threads.. I am using the P4 and it is working great in Arizona... clocking in at 200 after a 10 minute main.

the engine is alot easier to tune with the os p3, the p3 is a affordable plug compared to the grp plugs

I didn't see this addressed in here yet, I know a few people that have like a gallon to a gallon and a half of fuel threw they're .21 tuned GRP's and have no pinch to speak of, they still seem to run decent but hardly any pinch. I've got not quite a gallon on mine and it seems to be loosing it also, has anyone else experienced this??

Sleek - I have over 2 gallons on mine and it has a ton of pinch.

What break in method did you use? Also what are you using for fuel? Also what temps have you been running the motor at?

I know a few guys who have them as well and have a good amount of pinch..

mine has 4 gallons on it, and it still has pinch with the glow plug out, but i have had other engines loose compression after a gallon, sometimes its the luck of the draw

to break in I Idled 3-4 tanks then started leaning out and blurpping throtle, next 2 tanks I did short runs up and down the road, then I leaned out to race temps and put the hammer to it. . I run Byron 20% and temps are between 200-220, the first run of the day I always heat motor up with heat gun, but the rest of the day I just start with out heating. Every race day I install a new airfilter and pre filter, and every 2 rounds of qual. I install a new pre filter thanx for the info

Sleek - Sounds like you broke it in a modern fashion. I broke mine in slightly different but not much.

I idled one tank @ 180-190.

Let cool.

Put on track limiting throttle to about 1/4. Didnt really blip the throttle as much as pull smoothly. Made sure engine was up right at 180 for an entire tank. Let engine cool back down. Then repeated the procoess with pulling up to 1/2, then at 3/4. After that its been pretty much race tuned. I didnt really pull full 100% throttle for too long for a little bit.

I run Sidewinder 30% Worlds Blend. I am also running the AE factory team pipe which is the 2035.

I know my buddy got 2 GRP's the same time I did and he ran the GRP new GRP pipe that came in the combo. He ran Byrons 30 Gen 2 which is also good fuel. However his motor didnt have the mid to bottom mine has. Pretty much identical breakin procedure and he has a good amount of pinch as well...

Did you guys replace the con rod after break-in or is that not necessary on these engines?