I am going to continue selling Alpha motors but niether I or Kendall is sponsored by Alpha. My decision has nothing to do with which motor is faster. Both motors are very capable of winning races.

Rex

get of your high horses boys & read what was said
the carbies tune similar & both have long needles !!!
no one said this one is better than that one, or that they are the same
we're all sorry for your loss rex, probably non more than your son as he was getting great results, hey but that's life & time to move on

Sorry to hear your leaving the GO team Rex. Hope you will still pop up on here from time to time and share some of your wisdom with us.
Best wishes to Kendall and yourself for the future.

5 tanks is cutting it a bit fine Maybe they just want to sell lots of engines

12 to 15 tanks if you want the motor nicely bedded in and to last a long time.
Might seem a little long winded, but a bit of effort at the start with a new motor goes a long way. Heat cycle it for the first 10 tanks, then slowly lean it out until you hit 12 or 15 tanks depending on how it feels and sounds, then lean her up and go race hard. You have PM.

If the motor is bedded in, remove the .2mm break in shim. This will make a big difference.
It should be running .5mm - .4mm of shims. With the ultra hot OS P3 plug .5mm would be preferable.

NEW MG66X on line

http://www.massivemods.com.au/produc...roducts_id=359

is it okay if i only use .2mm or .1mm head shim on my 5port?will it damage the button and piston?fuel i use is 25%.

On 25% you ideally want somewhere between .3mm to .5mm of actual shims (there is .3mm built into the head button design).

Running .2mm will work, but on 25% you will need to run a med temp plug (OD 97T) or similar. Running a hot or ultra hot plug with .2mm will bring you into the zone of possible pre detonation and corresponding engine damage.
The other down side is the less shims you use the harder the engine is to tune and to get a steady idle.

Unless you are a very experianced tuner and know what to look for I would run no less then .3mm of shims with a med plug on 25%. The performance and run time increase is marginal, so better to play it safe.
Others will say they run less shims on 30% probably, but this is pushing it somewhat, and these guys will be very experianced racers and tuners.

I have found running .4mm of shims (that is .1mm less than factory) with the O'Donnell 97T Med plug on 25% or 30% gives me great reliability. No flame outs or blown plugs, plus my MG66 and GX Series motors have good run times and make more power than I know what to do with in this configuration.

Read this article on shimming GO engines

http://www.massivemods.com.au/produc...roducts_id=192

Just an update to let you know how i got on yesterday,

I had trouble getting a T3 plug and could only get a Dynamite med turbo plug, I fit this to the 7 port and put it back to factory, I tuned it near on the box and went out for practice - 7 min, i had little top end when the engine got hot, after marshalling i then warmed up the engine again and leaned it a bit more, the engine was better on top end next round but not so good on bottom, I then tuned LSN again and the next round was good.
ended up with HSN 3/4 in from flush and LSN 1 3/4 in from flush,
engine had plenty of power and smoke so ran it like this in the final.
Was running 3rd due to some poor driving on my part, sorted my head out and was getting better, engine then cut out after parking the car under a tube, tried to restart but plug had blown again, with 1 min of a 20 min final left i called it a day. engine was only getting 7 1/2 min per tank with a 7.5 mm restricter,
my sons 3 port that i tuned the same way was flying, he had a RB6 plug in his, he could only get just under 7 min per tank but he is heavy on the trigger.
Thanks for all the support and advice given as I think i am finally getting my head round the tuning now although I need to have a go at it on a non race day to give me more time to get it bang on.
Incidently my mate at the track has a GX 5 port and uses T3 plugs and blew 3 plugs yesterday, he tunes by the linked method and normally has his tune bang on.
makes me wonder as the T3 is a hot plug weather to stick with medium plugs with the go engines as we use 25% byrons fuel.

i LOVE these motors!

They are much older models than what is currently available.
You want the GX Series GX-5R Combo kit (with 2072 pipe). This motor and pipe will blow the socks off your truggy.
The older 7 port motors are OK, but you are giving up a lot of improvements and technology. Contact GO USA re the GX 5 Port.

Here is what you want - in the GX-5R model (best suited to truggy)

http://www.go-engine.com/go_engine-7.htm

need some help guys...started my engine yesterday on the track but i cannot get my engine to idle properly,adjusted the lsn clockwise,adjust the idle gap to 1mm,started the engine again and it will idle for few seconds,unless i pull the trigger,is this a sign of my engine having a bad glowplug?

engine hot or cold ?

not enouph info.

engine is already warmed up,when im not pulling the trigger i can hear the rpm suddenly drops and dies.

have u tried a fresh plug ?
how clean is your air filter ?

you also said you leaned the low needle . How much ? and then you increased the idle gap to 1mm, increasing the idle gap also richens the bottom again.

check what grizz mentioned 1st and then do a pinch test to check your bottom end tune and idle gap.. I suspect it's rich if idle drops 1st before dying as you described.

How to tune using the pinch method is explained in detail further back in this thread.