this engine is GREAT. i finally was able to use it last night for like 5 min before ANOTHER servo went out on me o well.

but i got some tuning tips and it helped alot. i left the hsn at stock and leaned my lsn and this thing screams. i radared it at 46mph and it was a little rich yet but its still new so i want it rich. this and the vspec are my two favorite engines

losi racer, I hate to hear that about your servo's. Get with Billy or Casey at the pit and let them help you. They should never, ever go out like that...

chris wheeler has my car, he is going to fix it for me, he said i could have my carb at to much of an angle.

Did anyone ever post a response to an alternative cooling head for the GRP engine?? Just to get away from the stock head. I saw the question but didn't see any answer.

any novarossi based head will fit. I have a old BF 3 port head on my GRP right now for brreaking the engine in.

Awesome engine, love the way it runs, idles all day long, never flames out, makes good smooth useable power and unbelievable run time. What more could you ask from a engine??

I just got my engine with a GRP #4 plug. Will this be okay to finish breaking in the engine or should I switch to a GRP #5 plug?

What would be the best method for break-in? Thanks in advance.

heat cycle method is the best if it will run with the #4 it would be fine

I just noticed the same thing when I put my grp non tuned .21 in my 8ight 1.0 yesterday. I even had ground a bit off the side of the center diff to allow the carb to be straighter and it's still turned too much for my liking.

I did however machine the chassis to clear the 2.0 radio tray so I have that done and the tray installed now. I was hoping using the 2.0 tray would prevent any throttle servo problems and then I read you are killing servos.....

I will post a pic of my engine in a few so you can see the angle I had to set the carb at to clear the center diff.

Overhead and closeup shots of the angle of the carb:







This shot you can see where I had clearanced the top center diff plate to help out some:



Does this look normal guys?

mine is a little more angled but that looks pretty good

I also noticed that when comparing the grp carb to my novarossi carbs that the grp is definitely bigger in size. The whole slide and carb boot assembly is considerably bigger in OD. This too contributes to the grp carbs having to be angled soo much compared to others I've ran. So now I noticed that I guess the grp setup is about the best it's going to get.....

Looks like your carb boot is rubbing yout center diff top plate thingy.

It is barely touching it and doesn't even push the boot in any. The carb opens and closes perfectly like it is and I'm not going to angle it anymore for sure.

i had this problem..check it often, when the chassis flexes it might rub the corner of the center diff. i was constantly getting holes in the carb boot, even though it didnt look close at all.