I have run GRP faithful since they came out last year. Recently I purchased an OS Speed and what a difference in the tuning. The speed tunes like a breeze compared to the GRP engines. I cant believe the difference and ease of tuning compared to the GRP engines.

NEED HELP
 

im breaking in a GRP .28 motor, heres how its set up

#6 plug
three copper shims, 1 alum. shim ( to take stress off con rod)
o'donell 20%
msr 1005 pipe.

4turns out hsn, 3.5 turns out lsn.

i have it in my MBX5T, and i cant get it to start to save my life. it just turns over with no signs of smoke coming out the exhaust. i did notice air bubbles moving back and forth in the fuel line. is that bad? i checked the glow plug and it working fine.. any help at all is appreciated.

this is just getting real irritating:flaming:

if you are pre-heating the engine then the heat forces the fuel out of the carb. i have had several grp engines and they all do that. i just prime it a little more.

thanks for the response...its getting fuel...ill prime it little by little then it just gets flooded....ive tore this motor down twice and dont see anyting wrong...im thinking about throwin my NINJA carb on there to see if that helps.

a Ninja carb is the same as a GRP but it might be worth a shot.......are you Sure its getting fuel ? it has no reason to not start if you got spark and fuel. :nod:

total BS!! i put i put my ninja carb on, same story...im getting a little smoke out the exhaust but it wont start!!!...im freakin lost now...ive tried differnt gas tanks... and my starter box started smoking.....lol that about all i can do now lol

the ninja carb needs a bushing to fit the grp. other than that they are the same

http://www.amainhobbies.com/product_...etor-Bushing-1

Ok. This is my story. When I would pre-heat my tuned .21 and try to start it, the fuel line looked like I had a huge air leak somewhere. Tons of large air bubbles in the fuel line. I checked the tank and seal many, many times. Nothing solved the issue. I checked the temp of the carb one time and it was near the same temp as the pre-heated engine. So I used a small toothbrush with some water to cool down the carb while keeping the engine warm.

Then when i'd put the car on the box Whalaah!!!, instant fire and purring like a kitten. The carb might be getting too hot and boiling the fuel before the fuel passes through the carb. So try to keep the heat off/away from the carb when you're pre-heating. I'll bet this solves your issue.

Let us know what you find.

sweet, ill try that out....also i just put in a OS P3 plug. well see if that helps first...keep them coming guys...:nod:

if your talking os in your grp you will strip the head button threads. try a odo97t. best plug for grp tuned unless you use grp. os plug are a totally different taper than the odo or grp plug

No, its not, but it might leak easier.
The cone is slightly different, but it works this way. Using GRP plugs in a O.S. would be murder - but then againg - who would do such a stupid thing?

I've been running OS p4's for ever in my GRP .21 tuned and never had a problem

i think that you should do some research...Geo-Y-Rock did a measurement and the os and grp are the same...

in fact, i have been using an os plug in my grp since day one.....and the was 2 years ago....so rest assured....they will work...

Ok, been told something else. Did not bother testing, why on earth should anyone put GRP plugs in an O.S anyways? Or even use GRP plugs?
Compared to OD or O.S. they're rubbish, IMO.

if your turns out are from bottom you will never get it to start ...it may be too lean on bottom ...stock settings are
hsn 3.5 turns out
lsn 6 turns out
idle gap 1-1.5 mm
take it back stock and leave the hsn alone and lean the lsn an hour at a time until it will idle ...you should be able to get it going ...but its all been said on this thread ..just search back about 20-30 pages :)

My friend is in bad need of a con-rod for a GRP .21 silver head. They are back-ordered everywhere and we need one by the weekend. If anybody has one they don't need or know where to locate a rod let me know. What other brand con-rod's will work?

novarossi r7 rod

I need a good carb other than a GRP for my GRP non-tuned... anyone???!

as i was removing my piston to put in the r7 i found a crack in the bottom hollow part of my piston. anybody know where i can find just a grp .21 piston? sleeve is perfect...and the rod looks great. i just need a replacement piston. i know some guys say dont even try with piston only but its bound to get a couple gallons. thanks for any help!

i dont know of others that fit? what are there?

O.S & nova.....

The R7 conrod does not fit. the grp pin is too big for the rod:cry: I have the r7 rod right here and there is absotutely no way its gonna work. any comments?

Hey guys, check out the speed shop thread on this forum. I have several GRP for sale at a good price.

Yeah that won't work Cookie Monster...I have not found one yet that works.


Try www.carolinasrc.com call them and have them check with horizon. Last I looked they had some rods in stock.

grp rods are nowhere..

i would think that grp parts will be getting very hard to come by now days considering they are only concentrating on tyres i hear now days

shit mark at powerhouse said it would fit ...didnt mean to mislead is there a diff betweenthe old p-5 rods and the new nova rods ?????

grp tires are now losi tires:nod:losi has all makes of grp. iv bought a few losi tires lately that still had the grp name on tire. as far as i know all r7 rods are the same. kind of sucks but its ok. theres only one way to know for sure:lol:

Yea, I got a parts order in yesterday and tried
a Novarossi rod. SON OF AH B-----!!!!!, I wonder
how many of us Mark told that rod would work.
Oh well, I can still use the rod in one of my GO
engines. Maybe one of the better known modders,
that is an actual machinest also, can come up with
a rod that will work for us. I know that there are a
few of them that have the knowledge and tooling to
do it.

Could the rod be drilled and reinsert a new bushing??
That would be awesome if someone could come up with an idea like that.
Wonder if GRP will manufacture any more parts for their nitro engines??
Someone has to know of an alternate replacement for these con rods..

Measure the GRP rod. Post the wrist pin diameter, crank pin diameter and the length of the rod. For rod length, measure it with the inside forks on the caliper in the holes. So you will have the length from the top end of the rod bushings inside diameter to the bottom of the crank bushings inside diameter. Then if you want center to center, just subtract half of the diameter of both bushings.

Once everyone knows these measurements, people with other motors and lots of old parts laying around (like me :D) can compare.

I wish KMW was still in business. Steve Kellum (Pops),
who is retired now, is one of best machinest there is.
He made and sold the first sets of super big bore shocks
and offered silicon impregnated hardened brass shock shaft
bushings. I know that he can re-bush a con rod or build an
entire new rod. Great machinest like him are getting to be
hard to find now days. I'm sure someone will offer up a
rod or rod repair soon.

I'll see what I can do.
There is so many people in need of this replacement con-rod.

i have a few grps and parts im gonna recycle. they went bust. damn shame. one of the first engines i started to buy exclusively for rebuilds etc... you ask me the old ninja case with new grp internals is one sweet machine. some super fine craftsmanship. all factorys have bugs but grp had too many apparently. i just dont see that its worth the hassle. replacement machined rods might be good for a production year but there after sleeves and other parts are gonna be toast. kind of like theres nothing like a good old movarossi or os and i hate to say that

There's nothing like a big bore,short stroke engine.

grp 21 0ff road motor NO PARTS TO BE GOT
 

l am so mad l just got 2 grp motors and now no new parts to be got can any one help me plz

Join the club.

Glow Plugs GRP
 

What other Glow Plugs will work with the GRP .21.

O.S. Seem to fit. O'donnell fits ok but not well.

What has everyone been running.

OSP6 for me. Ultra hot.

OS P4 has been good to me.
So.... will an nova R7 rod work or not?:confused: