Hey guys. I've been running a GXII-5R that I picked up from Amain when they were clearing them out. I've been having problems with tuning. I'm running the 2072 pipe with VP 30%. The past few weeks it's been running good but would bog on the bottom. If I tried richening the bottom I would get flame outs between 4-5 minutes into a tank. I had the LSN about 1 1/2 turns in from flush and the HSN was 2-3 hours in from flush. This weekend after a couple of flame outs a friend with 20+ years experience helped me with the tune. He also runs GO engines. He ended up raising the idle, fattening the LSN, and leaning the HSN. It ran good but felt like it wasn't making as much power. I've gone back and read through here and it seems like some people say 1-1 1/2 turns in on LSN and a couple hours in on HSN to the exact opposite. I'm getting really frustrated with this motor and need some advice. Thanks

your LSN is in way to far, from flush your low speed needle should not be more that 4 hours in. your hsn from flush should be about 3 hours in, try that and give feedback, make sure your idle gap is .07 to 1 mm

these engines tune kinda funny, you want them to run a little fat at first and the longer you run them they will richen up

Another carb question. I have a silver head 5 port Go, like maybe gen 4? It has a 2 needle carb. Anyone think it would be advantageous to go to the new gxII 2 needle carb. someone has them at a ridiculous price right now....

Mototech, your friend and Alwayswin seem to have it right, if you turn the lsn in much past flush you will starve the engine of fuel when the slide is closed, test this with the fueline pinch test.
to get the power back lean the hsn, i'm guessing its a 2 needle GXII carb, I have run them (hsn) 1 to 1.5turns in from flush without any problems, you will know if you go too lean, it will get a bit hot and flat out of the corners so richen a bit then, also if the straights are very long do the same.

it sure wont hurt anything, might be a little easier to tune with a little better run time. if they are cheap......doesent hurt to have a spare;)

GOTGXII21-2000-P2 carb for under 14.00 bucks??!!

Losi pipe
 

Has anyone tried the re12 pipe on these engines. Just curious :D

Well they're the same stroke as the novarossi engines, and afaik the re12 is similar to a 9901 pipe, so you'd think it might work. But I don't know.

i have and dint like it, seems to take away lowend and highend power. kinda like running the jp pipes on these engines, the jp2 was the best jp pipe. the 053, 086, 2072, or 0801 pipes are the ticket

Quick question on the GX-7R. I just picked up a Serpent Truggy with this engine and I'm looking for suggestions on glow plugs. What are the highest recommended as well as most redily available plugs out there? Thanks in advance!

I'll most likely be running O'Donnell Speed Blend 30%.

OD 97t (medium/hot) or 77t (hot)

Awesome, thanks!

O.S. P3 and P4, P3 for "normal" temperatures, P4 for warmer summer days

Thanks to you too! I love this hobby!

30% Nitro

OD T97 med or T99 cold

OS P4 or P5