let it cool, and then loosen the glow plug to let atmospheric pressure in. The cooling will condense the air in the combustion chamber and create suction. Tighten the plug again, then heat the head and the top of the case to 200 degrees fahrenheit. If it is cool outside, the piston should push itself back down, around this temp. This is due to the expansion of the air after reheating. You should preheat your head and case to 200 degrees before attempting to turn it over.

I did this procedure with a GX-5R on sunday and put over half a liter (800cc) of fuel through it before setting it on the ground. Engine was kept at 210-230 degrees for the entire period on the box, and total fuel consumption was measured with a fuel gun. I did this for 2 tanks (250cc). This was followed with another 800cc of fuel on track, without pushing the RPMs down the straights. Temp didnt exceed 250, and was spot on around 230. Fuel used was a fresh gallon of 30% of a premium branded fuel.

also... dont forget to return the piston to bottom dead center, in between heat cycles.

One other thing I'd like to mention: the appropriate temp to use when popping the piston back down, with pressure expansion from heat, will vary. This is based on atmospheric pressure, temp, altitude (above sea level), and humidity. It also will vary, based on how many head shims you are using. Use both shims during break-in.

Ruune,

Thanks for that bud, will give it a try tomorrow

You're welcome. Make sure you're measuring the temp at the top of the case, right under the head. That is the most accurate spot, since that is the pinch area and also where the heat is generated during combustion.

Also, make sure that you dont exceed operating temps with the heat gun.

I'm one for getting the motor on the ground and running in fig 8"s as soon as it's started - on the rich side with foiled head to keep the temps up. Out of interest, how did you keep the heat up in the motor with it running on the box ?

I used a combination of setting the idle up slightly (using trim on the transmitter) and wrapping the head with foil.

OK, cheers

It is fairly common for a motor to get stuck while trying to fire it for the first time. I think most people just take a screwdriver and pry between the chassis and the flywheel to get it back to bdc. Probably not the best thing for the motor so make sure it is still hot.
I usually get my motors to atleast 240 deg. when breaking them in, it also cools a bit before it fires. Then you will probably need to reheat it as it's running to keep it above 200 deg.
blow in the pressure line to the tank to get fuel into the motor before starting, you will hear the bubbles going in.
There are a few starter boxes out there that do not work well for breaking in motors, the ofna truggy start is the best I've used. I personally use a break in stand and works great.

Rex

Hey Runne, are you going to be importing the
new GO Engines flywheel and clutch shoe set-ups?
I see the flywheels are annoed the same color as
the GX engine cooling heads.
Link to pics; http://www.neobuggy.net/modules/news...p?storyid=7820

What's a good motor to get the 5 or 7 port and how good are these motors i here some good stuff and bad but I would really like to try this motor thanks

Go motors have been really trouble free for us, I've sold quite a few locally and they have all been great too. You will hear people have trouble with every brand out there. With the Go motors most of the people having trouble are new to nitro and bought a Go because of the better price. They probably would have had trouble regardless of the brand they bought.

As far as which motor is better between the 5 and 7 port it depends on the track and what vehicle it is going in. In a truggy the 5 port is an awesome motor, but only a fairly experienced driver should run one in a buggy due to the tons of bottom end power.
The 7 port is a really good buggy motor, especially on big tracks, it has as much top end as any motor out there.
The 3 port is just a really smooth motor, it is a great motor for someone with less experience. Not to say it can't win in the hands of a good racer, it can, but being smooth and easy to drive it makes a new racer not overpower the track.

Rex

5 Port for truggy and 7 Port for buggy - you can't go wrong.
The GX Series GO's are a very good motor and excellent value for money.
In the early days a few years back GO had some carb problems, which probably accounted for the bad things you heard. The motors have always been strong.
The Gen 5.5 and now the new GX Series have no such problems. The carbs are sweet and will hold a tune all day. Performance of the new GX motors is very stout. There are still a few die hard GO bashers out there, but their days are limited. These new motors are making a name for themselves world wide. Give one a try, you won't be disappointed.

And don't forget the MassiveMods MG66 as an option.

Works well in both Buggy and Truggy.

Im gonna put it in a losi buggy so I think I will try one them seem pretty good for the price

see if 22 racer still has any mg66 engines left, you will love it!