I wasnt just cruising around, i had been doing that jump and section of the track the same for both tanks of fuel and it only happened the once, followed by the flame out. I was pushing the car hard where i could. I have only leaned the motor out from factory about 3-4 hours and was having no problems at all, plenty of smoke all the way through. If i richen the bottom it is gonna be to boggy........

I guess i will need to experiment, a dry track would help thanks for the suggestions.

You may have picked up a blockage in the HSN jet. Sometimes the O rings on the needles dry out and little bits flake off them and can block the HSN jet, which causes all sorts of funny problems. By trying to tune these problems out you end up getting your tune completely out of whack. If it was running fine and then suddenly started to play up I would suspect it's something other then needle settings (which don't change). Either a blockage or air leak from fuel lines or tank.
Remove the HSN needle and blow some fuel through the housing to flush out any gunk in there, then replace the needle and set to factory specs (HSN and LSN flush) and retune from there. You might want to replace the factory O rings with some nitrile ones, or some fuel tubing (as explained in previous posts a few pages back). The original O rings flake badly and can cause a few problems from time to time.
Let us know how you get on

Cheers Grizz, thanks for the advice. That is why i posted as i wanted to make sure i didnt stuff anything up

The buggy needs a major clean, so that will be done first. While i am cleaning i will check the fuel tubing and tank, then the motor. See how we go from there.

I have only had 1.5L through it, should the seals go so quickly?

if there was muddy water on the filter there is a good chance some water got sucked into the engine , that could have caused a flame out ..

i am having an issue with random tuning for the last 2 meets and yesterday i noticed a leak at the back of the head, i checked the bolts and they were all tight so i removed the head and noticed the head button is extremely loose in the top of the sleeve, it can move about 1mm side to side maybe more. i can see marks on the shims where fuel has been leaking past . i have never seen buttons this loose they are normally a tight fit. the motor has only done 7 lt is this normal for the go engines or is something the cause of this?

out of all my go my buttons seem to be reasonable fit not loose are the head shims okey ? not starting to elongate at all ? it doesnt take make much for them to start leaking espeacly when one bolt is looser than the other and you would notice it more at operating temp more so as everything expands

Thats what i thought to start with, but the inner filter was spotless so i wasnt quite sure how it would suck water in. It is one of the most likely causes though.

At least i have a few possible causes now, will give the engine the once over when i clean up the car.

Thanks for the help. MM can you PM me your email address, my desktop is out of action atm, and ur email is on there. Cheers.

nah the shims look good,nice and round they still fit snug on the head button. i remember when i pulled it apart out of the box to fit the extra shim the button was snug in the sleeve but not tight.

interesting i wonder how the button has worn

Bring it up to meakin on Sunday...see if we can figure it out

Yeah, that's a weird one alright Sounds like it's really loose in there from the previous posts. I can't imagine what might have caused the head button to contract, or the top of the sleeve to expand, which is the other possibilty ?? Have you checked the internal diameter of the sleeve top with another motor ?

ok so i just pulled it apart again. hardly any slop while the motor is cold, i dont think i mentioned the motor was hot when the button was sloppy. anyway so its apart i check everything rotate the head button half a turn and put it all back together. it ran 2 two tanks no leaks or random lean bogs. its the best its gone since i bought it.
well its got me puzzled what was going on but its going now
thanks for everyones interest in helping me with this problem

As long as it's going good now, all is well
When you get a chance, drop the JP-4 off and fit a GO 2072 or 0801 onto the 5 Port. The JP pipes really aren't that suited to the GO motors. You will get much better performance and economy from either of the above pipes. The 2072 would be the best for all round power, with improved economy. This pipe is sweet on the 5 Port.

that is good news i guess if you have a problem with it again i would get another head button for sure all the best and enjoy

Hi Guys
I would like to send a massive thank you to Mark at Massive Mods for all his help and support in helping me to come 3rd in the Penrith district nitro on road buggy championship,I have put in some photos(hopefully)of my buggy with the new mg66,but the buggy won the championship with a mm5 5 port, Was the fastest thing there, but I had trouble with setup.This ran over 13 rounds and points tallied over championship.
Thanks Mark, your the man
Jamie