yep.

Need some Advice Please.
 

I would like to know how you guys prep your engines after a day of racing to make sure they do not form any type of rust between races. I have a GXll-5RHO with just over 5 gallons of Power Master 30% and I lost the engine this weekend wile racing. When we took the engine apart it was eat up with rust. I always try to make sure there is no fuel left in the engine at the end of the day and I race every week so the engine never sits for any length of time. I am sure there is something I am doing wrong and any advice I can get from you guys sure would be welcomed.

Thanks
Heywood

I don't know the oil package of Power master but typically a fuel with a reasonable ammount of castor oil will have good protection against rust and will only need after run oil when storing the engine for a longer ammount of time. Fuels that are syntetic oil based usually need some after run oil after every run to prevent rust.

Any fuel residue left inside a motor will start rust forming within 24 hours if left.
The methanol is very hydroscopic and will attract moisture at every oppourtunity. This moisture reacts with the nitro to form surface rust not only on the crank, but inside the bearing cages etc. Anywhere there is a fine coating of fuel left on a suitable surface.
Best way of preventing this is to run the engine out of fuel when it's hot. Then disconnect the fuel line and turn the motor over for a few seconds with the glow starter attached so as much residual fuel as possible is burnt off inside the crankcase. Then after run oil the motor everytime you use it.
On top of this, check your motor frequently. Strip it down and check for any roughness or notchy sections on the bearings. Put your finger inside the inner race of the main bearing and rotate it with some downward pressure on the balls. Quite often the bearing will feel ok if you just spin it gently, but when you apply pressure to the balls and cage it will feel "gritty" or rough. If in doubt, replace it.

Craig (curacing2) our team driver here, stripped down his original GXII-5RHO the other day after nearly 5 months of hard use and 6 gallons of fuel. (I know that sort of contradicts my last post a little, but this motor was inspected regularly along the way, and was a bit of a test motor if you like).
This was the very first GXII landed here in early March this year, and it was pressed into service at a 3 day event with only time for 3 - 4 tanks of run-in (came 3rd overall).
On inspection after 6 gallons, the original bearings (front and rear) were still in mint condition and smooth as.
The rod and crankpin fit was still snug. No discernable movement.
This was the original rod as well. Nothing had been changed in this motor since new.
Pretty good result, especially seeing as the motor was rushed into service without a gentle run-in period.
Goes to show the quality of the engineering and componentry is right up to the mark. :)

anybody experiencing cooling fins falling off?after 2nd qual i had one come off.i split it and pulled it off.after 3rd qual another came off. i ran it in the main its just rattling around now.its the gx11-5rho.

I did hear of a couple early on from guys on here (in the US), but nothing down here in NZ. We have 60 + of these running around with no problems at all to date.
It's vibration / harmonics that cause the fins to fracture. Fit some fuel tubing as a precaution from new as shown in the pics and you won't have any more problems.

no problems here in northern lower michigan! i did have one come loose on a GX5R last year. but so far the GXII's have been FLAWLESS!;)

I <3 Go

hi shane, your right. Returned all needles to stock (flush) and retune. LSN was WAY TOO LOW. thanks for the help..

Great news :)
Once you have that idle gap set and a good tune on it, the GXII will hold it's tune very well.
Just tweak the HSN ever so slightly if required (1 hour either way will normally do it) for day to day changes in ambient conditions.

Thanks I'll try that on the one I haven't ran yet. It's #35,the fins came off #6.

Nitro- North
 

Just wanted to say very fast service from Moto Matt. ordered 3 con-rods on Friday morning and got them in Mondays morning mail.
Cant get any better than that.

Kevin... I'll take a look this weekend, if you're at RCHQ. Just need to make sure that there are no impact marks on the fin(s) that broke. We'll work something out.
Trey

Thanks Trey, I won't be there this weekend but will the following week. Imay break in the other one in the meantime.:)