I'm running the P3 in Tucson, Arizona with temps coming in 180-190 and the motor is so well rounded from bottom to top end it makes a truggy (X2 CRT) very hard to beat..

"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??"

Is the engine still idling? Whenever I saw motors lose pinch I also saw the idles consistency turn for the worse.

I just got done with ther break in of the GRP .21 tuned version, mounted in my MBX5T, 1st off any of you that said it won`t pull a truggy can stop posting on here, you don`t now what you are talking about.This motor rips
I had to start ther break in with the OS P3 plug, it wouldn`t stay running with the 5 or 6 being so rich, I switched to the #5 when I was finished with the break in and had no fuel leakage at all, maybe I was lucky. either way I like running it with the #5 we`ll see how she lasts.

good luck with all your GRP`s

A question ....

Why are you guys using OS plugs to the GRP tuned engine ??

We have been using GRP engines since January and have always been using GRP plugs (no 5 or no 6). We hav never broke a plug and the engines ( we have three of them) is running perfect in high level racing in Sweden.

the engine was very eratic for me with the grp plugs, it was alot easier to tune and get to idle with the os plug, once you try the os plug you wont go back to the grp ones

$10 vs $16

Here is te explaination of Ninja/GRP
Mugen Seiki broke the contract with GRP because they were having problems with Ninja engines preaturely failing and not performing. This was mainly with The on road engines but there have been many off road engines doing the same. GRP was also making their own engine line and it was the same engines as Ninja so Mugen Seiki went to O.S. to have them design and make them engines.

Quote:
There were two lines of ninjas.
A regular MR Ninja and a MRT Ninja
The regular ninja is the most common.
They made the following:
MR12T01A for on road touring car
MR21B01A for off road Buggy/Truggy
MR21R01A For 1/8th scale on road
MR28M01A for monster truck/truggy
The tuned they made
MR12T01AT Tuned for on road touring car. This engine never really sold well but isnt uncommon.
MR21B01AT Tuned for off road Buggy/Truggy. This engine sold decently but like all of the others they werent out very long.
MR21R01AT Tuned For 1/8th scale on road. This is most likely the most popular as the Mugen Team raced with these. They also did very poorly and caused many DNFs and loss's for Mugen cause of its unreliability and failures. They primarily developed the Tuned line off these as this is what engine they started on.
They never released the MR28M01AT Tuned .28 engine.

The Tuned ninja line didnt last very long because Mugen went elsewhere looking for a Ninja engine manufacturer. They are now with OS. The os is the JX21B01. GRP started its own line of engines which are the exact same engines as the Ninjas except have a different cooling head and name on them. They have yet to release and Regular engines but have instead just release Tuned versions. Every single GRP engine says TUNED on them and are exactly the same as the Tuned ninjas. Some people are saying they have differnt parts and timing than ninjas and that is because they are comparing a Tuned verson to a regular version. Compare a Tuned Ninja to a GRP engine and youll see the exact same thing. The only difference other than the cosmetics is the GRPs have the super Alloy head and the Ninjas had mostly the Magnesium head. Ninjas switched to the Super Alloy head on the on road engines to try and help with reliability and tuning problems but that was done right after Mugen and GRP terminated their partnership.

Summary

MR12T01AT Tuned=GRP Tuned GT01-12TC
MR21B01AT Tuned=GRP Tuned GT01-21BU
MR21R01AT Tuned=GRP Tuned GT01-21ON
and what would have been the MRT28M01A had it ever made final production would be the same as the GRP Tuned GT01-28TR

The GRP Tuned GT01-21RA Was never in the Ninja linup. Its most likely just the GRP 21 buggy engines with a changed timing profile to have a better power curve for the RALLY GAME Racing class thats big in europe.

__________________

I am not really sure where you got the above information, but I was told by a couple of distributors (John of carolinasrc, and a tech from amain) as well as mugen that grp basically screwed them over. They created the Ninja and it turned out to be such a highly sought after product, they basically stopped producing it and concentrated on their own line. (changed the ninja name, rounded a couple numbers another way, changed the timing oh so slightly and BAM the new GRP) Even the pipes are the same (2053's)

One things for sure though, Mugen would not swap over to OS just because they wanted too.... they had too. Why on earth would you change manufacturers when the product was such a hit? (and less then a year after initial production no less) That would not look good on their company at all!

I dont know what Mugen was thinking leaving JP every one know's JP engines are da shit so why bother having your own engine line why not just stay teamed up with the best engine modifier in the bussiness and keep winning with them

I have been using the GRP #6 plug in my GRP and it really works great. The motor comes off at 205 every single time. In the last 3 race weekends I have not had to touch the tune at all. The motor works great. 3 race weekend 3 A mains 45 minutes each, and still comes off at the same temp. Even after running the 30 minute B main then bumping to the 45 minute a main the motor keeps on trucking along. Not a single flame out in any main or qualifying. I could not possibly ask for any more from a motor, the thing gets me 10 minute fuel runs at race pace.

I am very happy with this motor. I am pretty sure my losi buggy is very happy with this power plant as well.

I've had my GRP all summer and still has steel pinch on the top. (3 1/2 gallons) The above post about Mugen drivers loosing pinch is funny to me because they decided to go with OS. I have an engine pinching business and the Model I see the most business from is OS. They lose pinch faster than any engine I've ever seen. I've owned a few of them as well. I love how they run. But I can't afford to resleeve the things every two gallons. The materials that the GRP engines are made of are simply second to none. Japenese engine makers aren't up to par with the Italians.

I'm running a B01A with Ninja 6 plug,what pipes are you guys using in buggy.Has anyone tried a JP4,if so what runtimes you gettin? 30% 11%oil Byrons is what I use

i would recommend the 2035 associated or thunder tiger pipe for the ninja or the grp engines, it really wakes the engine up on the bottom and mid range, but still has all the top end you will ever need, if you have a novarossi 9853 or 053 that is also a good choice with a short manifold, and the mugen msr 1005 is awesome on these engines as well, i get 11 min run times with the 2035 pipe, 6.5mm restrictor, and os p3 plug, that engine dosent come alive till you get it around 220-230 its a different animal when u get it upto temp has good power everywhere

Just a quick question: Does anyone have any experience with the GRP race engine? The "non-tuned" version.

Just wandering it its worth a try... Almost $100 less than the tuned version...

The tuned grp's are amazing!

My guess would be the reason they are in business in the first place.. to make more money.

OD99T here...First tank of breakin was with the C4 GRP plug. Then switched to O'donnell since I run them in my Speeds without any issues...No problems so far. The OD plugs will work...