tommorrow i'm going to run in my go gx-5r motor. i'm currently using fuel with 9% oil (nitro x hp173). do you think i should add some additional castor oil for run in? i was thinking of adding 40 ml to a litre of hp173. would this be beneficial? ive got coolpower fortified castor oil.

Thanks Giz

Hi Voodoo - nah, we recommend running in on the same fuel you will be racing with. You will be running on the rich side for the first 12 or so tanks anyway, so it will get plenty of lubrication.
The only time we don't recommend this is if you use 30% fuel. We reckon 30% is a little staunch for a brand new tight motor. The higher % nitro raises the compression ratio a little, which is not what you want with a super tight motor. We still add the .2mm shim for run in to lower the compression ratio, so running 30% would be self defeating. You can change up to 30% after .5 of a gallon or so once things are starting to free up and you have removed the extra .2mm shim.

cool thanks grizz. do i need to change settings or leave the needles as they came from factory

With the GX Series, leave the HSN at flush (should be set flush from factory).
The LSN will be flush also, but wind it in 1 full turn.
This will give you a pretty rich motor, but it will run.
During the first tank, maybe come in 1 HOUR on the HSN and 1/4 of a TURN on the LSN to get the motor where you want it - just a little rich and spluttery, but not really boggy.

As you go along with the break in just lean a little at a time as the tanks go through.
A race tune on the GX5 (allowing for ambient temps and fuel brand etc) will be close to: HSN 2 - 3 HOURS in from flush (never much more) LSN 1.5 - 1.75 TURNS in from flush.

hey guys after a two year break from the hobby i decided to come back. and i have two go 3 port race engines..older ones maybe gen3..after a clean up and mounted on my buggy(z-car). the engine started right away..my question iam using a 086 pipe that i really liked.would the 2072 be a better pipe for the older 3r. or is it for the newer engines...would it give better fuel milage... thanks

I liked the 086 with my 3ports. Worked good with all the go engines. The go plpe is also good. The go plpe gave a bit more mileage for me.

Thanks Grizz..I've put a litre through this engine now and I must say it was very easy to run in. The T3 glow plug lasted through the run in process and still is in great shape. When should I change to the 97 T odonnell plug.

On another note I've got the 8m restrictor in the carb. Do I need to retune if I put the 7m restrictor in. What's the difference in performance in moving down to a smaller restrictor?

cheers

That's great Voodoo.
Just keep running the T3 for a while longer. Normally when you start running the engine leaner after break in the original plug gives up and dies. They don't like the transition from fluffy rich to lean that much
If the motor goes a bit flat, just change out the plug for the 97T.

Changing down to the 7mm will make a minute difference. You will lean just a hair to allow for the slightly reduced total air flow the smaller restricter provides. The 7mm is a nice trade off between power and run time. It will smooth the motor out a fraction. You won't see any noticable reduction in bottom end, but maybe just a smidge less top - you may not even notice. Run times will increase slightly with the smaller restrictor.

When setting your throttle end points with a smaller restrictor fitted - take out the restrictor to set your WOT end points. Then reinstall the restrictor and tune from there. This will let your carb slide / needles etc work as normal, the only difference will be the restricted air flow from the smaller restrictor (which you will tune for).

Hi.

What's the difference in conrod #21-0600 and #28-0600A?

Thanks gentlemen

Hi Lille-bror,

I don't know where the "A" came from, but the listed part number in the GO parts order spreadsheet is just 28-0600.

The 28-0600 is an early model con-rod, which was used in the Pro Series .21, .25 and .28 motors up until the Gen 5.5 range came out.
These Gen 5.5 motors had a new and improved crankshaft design, which went hand in hand with a new and improved con rod - the 21-0600.
The Gen 5.5 morphed into the GX Series (which was still a 5.5 model, but had the Ti coated crankshaft and other improvements). The GX Series continued to use the new 21-0600 rod.
In 2011 the GXII-5RHO motor came out with a completely new lightened and epoxy ramped crank, which still works inconjunction with the 21-0600 rod.

There was some quite heated debate a while back regarding the difference between the bushing sizes on the 28-0600 and the 21-0600 rods.
To the best of my knowledge the early cranks (prior to Gen 5.5) had a slightly smaller crank pin. This was found to be rounding out and causing slop in the con rod bushings on these earlier motors. When the Gen 5.5 crank came out, it had various mods including a slightly bigger crank pin to alleviate the issue. This gave way to a stronger and improved con rod (the 21-0600) with a fractionally larger big end bushing to match the new 5.5 crank, and all subsequent cranks developed since then.

So in theory, your better not to run the newer 21-0600 rod in the older motors with the smaller crank pin.
We advised customers here with older motors to upgrade to the newer Gen 5.5 (or more recent) crank and the 21-0600 rod as a package (and gave them a package deal price accordingly).
Hope that answers any questions you might have had

DAMN!

Now, that's an answer! Thanks a million, Grizz

I just got a Axe Rossi Serpe engine for nearly free, and I'll need a new rod for it after break-in. Heard GO rods fits, and we have a GO distributor here in Denmark, so the rods are easy to get.
I must meassure the crank pin to know which rod to use. What's the size of the newest GO crank pins? 5.00 mm?

GO Racing NZ Ltd now on Facebook - http://www.facebook.com/goracingnz

Probably of more interest to the New Zealand and Australian guys on here so they can keep up with the local South Pacific scene in more depth.
Please feel free to visit and comment, add GO related pics etc. If you do visit, don't forget to "like" us

Correct 5.00mm

Yeah, bit of a ramble (as usual). But you know what they say - knowledge is power

Power on Grizz1:
Any sign of the video yet?
Carefull ;Flanno is watching. (HI FLANNO, and HAPPY NEW YEAR)