yes they are that sinsative ....also they need to be warmed up more than you normally would ...10-15 passes up and down the street ...and just the normal letting it idle for a few minutes on the box ...easy to miss tune because the motor isnt warmed up ...so you think its too rich ...then if you crank it and tune it right away its just a downward spiral from there ..warm it up good and small adjustments works best on these motors :nod::nod:my .02

These engines new to be warm in order to perform. I let mine idle on the box 3-5 min before my qual or main and defiantly make sure to run it 3-5 min on the track before I even try to change the tune. I have a modded tuned .21 so I know mine is more sensitive but it is seriously sensitive. When these engines are cold they will sound so rich like they are going to die and they will. Keep it running and let it warm up, then tune it. Once they warm up they lean out, so if you have it tuned perfect but its cold or not up to running temp when you run your race it will lean out and heat up and bog in performance.

i fell for this mistake tuning your engine befor it is warmed up and the stupid thing was i already dam well new :rolleyes:

guys i got a question about pipes and headers now the one that comes with grp i have no issue with at all but i hear compared to other pipes the engine performs a little better....
i have been looking at pipes has anyone used the losi pipes at all ? it would be nice to get just a little more bottom end out of the engine... it certainly does not lack at all during races

Frank L what have you had done o your grp you say it has been moded how does it compare to the tuned grp in performance ?

Powerhouseperfoemance.com I did the turbo mod to a fund and it's better all around better bottom better top and a wider mid range. It's smoother and idles forever. Tunnning is a little more touchy but when it's right I can pull away from everyne else on the straight. Jumpng is easieroverall it performs more like a .24 perfect for a truggy, insane in a buggy. Check put the powehouse engines thread and then vice mark at powerhouse a call he loves this stuff and he likes for you to call. I send all my engines to mark now. I have 2 .21's and he's doing a .28 for me now Dow large tracks.

I feel dumb for asking this but here goes. How do you remove the carb from the GRP engines? There I said it. LOL.

So I have between 1 to 1.5 gallons of fuel through my engine. I started setting a race tune in yesterday but she was running erratically. Half a lap would be absolutely perfect and the other half would be so rich the car wouldn't move at WOT. Yikes! So I decided to finally break the factory seal and seal the carb, high speed needle, and backplate. As well as grease the o-rings with some o-ring grease.

I can't remove the carb though. I removed the pinch bolt and the two aluminum carb retainers. That leaves nothing else, that I can see, to hold the carb in place. The carb will rotate just fine, but won't come out. What am I missing? Also is there a gasket or isolator between the carb body and the engine case? I was gonna try using a flat blade screw driver to help things along but this gasket/isolator was too soft and I didnt' want to tear it.

After sealing all the o-rings with grease and sealing the HSN and backplate the tune was much more consistent. Although every couple of laps there would be a big exhaust cloud and the engine would be down on power for a small section of the track. But this was every couple of laps or so.

The engine is running great so far, other than those issues. The temps I was getting were 210 after 7-8 of race pace driving--with no mistakes actually. And I'd just check the temps when I'd pull in to refuel.

So overall it just sounds like I have some of the "bad" o-rings and I need to get new ones coming but for this weekend the o-ring grease will have to do the trick.

its like a pinch bolt ...so if you have the bolt still in the case ...you would loosen it not all the way out ...and you would stick you hex driver in the bolt while its loosened and tap the butt end of the kex driver with like another hex driver it will loosen the pinch on the pinch bolt and allow it to loosen up and pull out

Yep. All three pieces of the pinch bolt assembly were out. there was nothing in there to hold the carb. I do like how GRP uses o-rings on the two aluminum pieces the pinch bolt pulls together. That's a nice touch.

Anything else besides the pinch bolt and retainers? Do I just need to get rough with it now? LOL.

Engine Tuning Experts
 

OK Gentlemen, I have a question that not only applies to GRP engines, but to all of them.

What does it mean, when after a high speed pass you apply brakes, and the engine revs high for a couple of seconds and then idlle drops down drastically to the point that it will die?

I was reading an article by the late Ron Paris, and maybe I misunderstood, but there is states, that when coming off a high speed pass, you should listen to the engine and it should have a slight high rpm before settling and if not to continue to lean the LSN......

Any help much appreciated....

Try raisng the idle or leaning the lsn. When you 1st start it does it idle?

lean the low speed ..you may have to also lower your idle after you lean the low speed...plug may be crapping out also if it wont hold a idle and the engine still has good compression

Let's narrow it down:

1)Brand new plug
2)Engine has very good compression
3)No air leaks

Tune.

Wow can you read minds too?

If you make something really obvious :lol:

Richen up the the HSN just a little, 1/2 to one hour. your runnin too lean hsn

i saw this on neobuggy today,



- GRP stop engine production, focus on tyres?


Got Gossip ?
[email protected]arely 4 days after writing, "I am still runnning GRP engines at this time. we will see what the future brings but as for now still GRP." in our Live Q & A, Mike Truhe has switched to Orion engines for the remainder of the 2009 season. After Adam Drake's departure to Novarossi, it seemed only a matter of time before Truhe would find a new engine supplier. The Losi driver will debut at the Euro warm up in Austria next week.


always sad to see and eng manufacture having a tough time.

I have 3 new GRP's for this season for my truggy, 2 .21's and a .28 I will run them till they fall apart, they treat me well.

Bummer, The GRP's have been great engines for me. I am currently running the .21 &.28. I just installed new TKO ceramics in both engines last week. Maybe A guy should buy an extra p/s & rod before everything is gone.

fuel?
 

I'm just getting into 1/8 scale racing and just purchase a GRP engine. I was wondering is there a different in the nitro brands? Or should just be the same brand from my local hobby store?

Either that or do the Drake and switch to nova.

A-Main only has one GRP Piston/Sleeve 5 Port-ABC (.21)[LOSR2044] left.
I bought one this afternoon.

are grp people realesing a new grp????

no

Sucks to hear the bummer news about GRP.

AFter greasing the o-rings for the HSN, LSN, pinch bolt pieces in my carb and sealing the back plate, the engine is working great now. I can't believe it still has that much power with a 6mm carb insert and yet only runs 200-210 degrees. It's just crazy after what I'm used to in the past years. Loving it and hoping GRP will pick up production by the time my engine wears down. LOL

So is GRP officially stopping production or is it still just speculation? I can't find any hard facts on it.

this is not good news i did hear about this a while back that grp were going to stop production of there motors...

sounds like it is time to start searching for a new motor to use ....

It's really a shame they produce a great product. I have run them since they came out and they run well. I will run what I have and then switch to nova or maybe trinity I don't know. I just hate to see a good company that produces solid reliable products go under.

your rite frank im not sure which way i will go maybe try a new os i have looked at the nova motors not sure which one i would get but :confused:

This was posted up on Neo-Buggy on 4/22/09

Former GRP engine designer Mario Rossi has joined forces with Italian distributor Schepis Model.
The two have been in business during the early days of GRP engines with Schepis Model's 'Boss' branded GRP engine. Salvatore Schepis and Mario Rossi announced the deal last weekend at the first round 10th scale touring champs in Mesero.
Schepis tell us that together Rossi and Schepis will develop and produce a new range of SchepisModel branded engines. Given that we received the news, an offroad engine looks pretty likely!

this sounds promising

not to sound silly , is there a web sight at all of the company has joined with any info ? just to keep tabs on any new motors been released:nod:

what are teh bearing sizes fot the grp tuned???

Go read again. i dont see that top part. if this was real there wouldnt not be one pro driver still runnin these engines.


same as vspec

front-7x19x6mm

rear-14x25.4x6mm



BTW ANYONE LOOKING FOR A GRP CONTACT ME.....

I just installed new tko bearings in it, ran a tank on the new bearings. but it needs a piston and sleeve. ill include a pipe and header(053, not lookin to seperate due to not needing the pipe anymore unless i have a buyer for the engine and pipe) for 100 SHIPPED inside us only. the pipe is dirty due to shoe glue from the body melted on it havent tried to clean it....

the grp has maybe 4 gallons thru it. the front bearin started leakin and i replace it to late and there is almost no compression. it still runs but it flames out every once in a while. PM ME IF INTERESTED

so they are still making these motors or not ?????

No.

Time to buy orion Alpha's. sucks. I loved my GRP's

tuned 21
 

http://www.rctech.net/forum/r-c-item...ml#post5763720

If anyone is looking for a nice GRP 21 look here.

it is sad but good bye to grp got my new motors now will have to try out hope they are as good hopefully alittle more bottom end would be nice

post where you got this info please