What size restrictor do you normally run with this set up Rex ?

Most of the time we use a 7mm restrictor. I was talking with Ed Bridges a while back and he also recommends this.

Rex

im going to try my 7 port with the 97T plug tomorrow instead of the T3 and with the .2mm extra shim removed..probably not good to try all this at a national meeting lol but needs must

anyone know why some countries got the long needle and some got the short needle?

what i do find with the long needle is that as we travel all over the UK sometimes 200-300 miles to a track, the engine seems to change tune quite a bit,fine at one track,rich and boggy at the next with no change to tune,never really noticed this change with previous engines and yes i know humidity and barometric pressure changes the tune but it does seem over sensitive.

im wondering if the long needle is making the tune hyper sensitive and thats why the engine seems to be so far off tune sometimes..im wondering if going to the short needle will be better.

what i mean when i say " Shims Total " is the " Total amount of shims " I never include the .3 mm step when i recommend a shim measure.

Just forget the extra .3 mm , its built in to safe guard people running too few shims and butting the piston into the head button. Actually its built into about 80% of engines head buttons .. of all brands.

The information is there to help people who want to go into advanced shimming technique to find the ACTUAL head gap when calculating trapped and geometric comp ratios so they can gauge fuel mixes and plug choices. Shimming is a crutial point of tuning for any engine. If you want the very most out of it you really need to understand shimming. Yes its a bit advanced , some will get it some wont , either way its ok.

The info is there if you want to go the extra step , if you don't you can happily run the standard shimming and have a great running engine.

Hope this clarifies things

If the engine had air leaks it would most probably idle longer.

When you start the engine and pinch the fuel line how long does the engine take to die ?

mark, what is acceptable pipe temps? I am having trouble with my mg-66. I know about the shim stacks, and melting bodies.but what would you rec for clutch springs? It's the initial snap. almost like rich for second then wild ass ride.I am using answer clutch system with the 1.0 spings,go-tec 2072 pipe,30% byrons gen2 nitro. I will be going to the Amain 30% nitro from our U.S. distributor after I finish off my 1.5 gallons. I tried the amain25% nitro. what I like about it is how clean it burns. Inside of engine was perfectly clean. I am really wondering knowing what I have learned from this site and yours,if 20% nitro is the way to go. I know there is all sorts of things that go to pipe temps,but if you could point me in the right direction It would be appreciated.

WELL I TOOK EVERYONES ADVICE AND TUNED IT BY PROFORMANCE AND RAN MY .28 6 PORT AT THE OFNA RACE THIS WEEKEND AND IT DID GOOD FOR A LITTLE BUT RUNNING 300 WITH PLENTY OF SMOKE AND THE SECOND HEAT RACE THE ENGINE WENT PLOP. NO MORE ENGINE. LOST ALL COMP. ONLY HAD ABOUT 1/2 TO 3/4 OF A GALLON OF FULE IN IT AND SO I GUESS I WILL THROW THAT ONE IN THE BOOKS. KINDA MAKES ME MAD THAT I DID WHAT EVERYBODY SAID TO DO ON HERE AND FROM GO TECK AND WITH SO LITTLE FULE ON IT SHE LOST ALL COMP.
ANYBODY CARE TO TRY TO ANSWER THAE QUESTION ON WHY IT DID THAT
OR JUST MAINLY THE ONES THAT TOLD ME TO RUN IT LIKE THAT

Well if you use high quality fuel and you really have smoke from the pipe ALL the time it really should not get at 300deg. Maybe your gauge was off or it was excessively rich on bottom and way to lean on top and it actually did not put out smoke on full throttle ? Also running it should not kill the compression completely in such a short period unless the engine gets dirt in. So are you 100% sure your filters were OK, neck had zip ties etc. ? It's really hard to believe you trash an engine in such a short perod of time w/o having some serious issues

Hey all,

Fuel question:

I've been running Byron's Gen 2 Race 30%, but two LHS closes later (), the third LHS (if an hour away is considered local!) had some bad experiences with Byron's Gen 2 and doesn't carry it. They recommended Sidewinder instead.

Any concerns switching? Running Go Tech 5 .21 in buggy, broke it in on Byron's. Got a big race in three weeks and don't feel like trashing my motor just now.

I know exactly how you feel. I trashed several motors over my first year of racing after only a gallon or 2. I tried blaming everyone for it. It turns out that it was my fault the whole time. I was getting dirt in the engine in a couple cases but the number one thing I was doing wrong was simple tuning things. I was running my idle gap to open which made me tune my top end way to lean. The number one symptom for this is that the motor run really strong for about the first 3 minutes and then the temps start to rise and just keep on rising the longer you run.

Now that i know how to tune. I am still running the same 2 go tech motors I ran all last season for local club races. They both got new bearings at 2 gallons but my 7 port has over 10 gallons on it and my 5 port is going on 8 gallons. both of my GX race motors have over 2 gallons and both still have very slight metal pinch. I personally still check my temps as a back up after every run but that is just to make double sure my tuning is right.

No problem switching from Byrons to Sidewinder, We run Byrons but used to run Sidewinder with no problems. Depending on oil % you may have to retune and hour or 2 but thats it.


Rex

Hey im having problems tuning my car. I have my idle set good. but sometimes i bring it to a complete stop the the car idles really high but other times i bring it to a stop and it idles normal. The carb is all the way closed, im sure of that. It also will run good for like 2 minutes than it goes weird again. Does this sound like an air leak. I got the carb, backplate, the carb bolt, And the little rubber thing on the carb sealed off. I dont know whats going on. Any help would be appreciated. Thank you.

Hey Go Guys.. i hve a 3 Port blue head with turbo button and normal head i am trying to get rid of. Only has 1 gallon on it including the break in. It rips in the truggy, just have no need for it anymore.

I figured i would let you all know... i want $60 for it, and have a GO pipe for it too, and would take 30 for the pipe...

if interested, PM me

ran my 7 port today in the UK nationals,using 30% and od 97T plug with the stock shims..engine was a missile

getting around 9 and half minutes i reckon with what was left in the tank..shame my rear driveshaft sheared in 2..too much hp lol

Hi guys.

This is a serious question so please don´t start any bashing.

I´m considering trying the GO engines and I have been using a OS V-Spec and I´m satisfied with it but I would like a more mellow/controllable bottom.
It hits like hell on the bottom.
I´ve tried a couple of my friends Novarossi +4 engines with the exact same car/setup as my car including the same clutch-setup and damn it´s a nice engine... Smooooth and fast with good runtime.

Should I try the GX-3R, GX-5R or GX-7R if I would like an engine to perform like the +4?

Thanks for your time.