O.S. 3.5 Outboard!

[Bill Gibson]

Never had one until now! Its hanging one the back of my G30! I wanted to know:
What percentage of nitro is good to run it on? It will be raced!
Whats a good prop to use?
What do i use to lubricate the flex shaft? I see a fitting on the right side of the lower unit, so i assume thats where the lubricant goes!
Any other advice would be greatly appreciated! thanks!

 

[Grimracer]

Bill,

50 to 60 is fine... (18 or more percent oil, based on viscosity)

I like a 1440, back cut 17 deg and set to 2.9 cup... BUT.. your boat will tell you what you want. The Grimracer 40x52/3 also works quite well.

I use Grimracer Speed Grease after 5 rounds and just run the extra pressure tap to the shaft nipple.

TUNE THE LOW SPEED NEEDLE.. DO NOT CUT IT OFF... (just trust me on this one).. this goes for ANY motor ..if it has a low speed needle,, TUNE IT!

AVOID a set up that allows you to run WFO for the entire lap.. Set the boat up so you have to use the throttle.

Grim

 

[Bill Gibson]

Many thanks friend! Some where in my stuff I have THAT prop!

 

[the german]

Bill
Mike forgot to mention that no head shims are needed.

Alex

 

[Bill Gibson]

Thanks Alex! Appreciate it!

 

[Grimracer]

I have ran 50MPH with or without.. but Alex is right.. go ahead and remove the shim if its in the motor.

Grim

 

[Mark Anderson]

Follow what Mike and Alex have said. Run a hot plug. 1L was always my favorite, and be gentle during the brake in. We use 66% with 17% oil

 

[Kris Flynn]

Bill,

50 to 60 is fine... (18 or more percent oil, based on viscosity)

I like a 1440, back cut 17 deg and set to 2.9 cup... BUT.. your boat will tell you what you want. The Grimracer 40x52/3 also works quite well.

I use Grimracer Speed Grease after 5 rounds and just run the extra pressure tap to the shaft nipple.

TUNE THE LOW SPEED NEEDLE.. DO NOT CUT IT OFF... (just trust me on this one).. this goes for ANY motor ..if it has a low speed needle,, TUNE IT!

AVOID a set up that allows you to run WFO for the entire lap.. Set the boat up so you have to use the throttle.

Grim

Can you please explain tuning the low speed? How you do it with this motor that is?

Do you still like the ODO9 plug? Which is a cold plug?

 

[the german]

Kris
I use in all my .21 motors a OD 287 plug.
It’s a variety of OS outboard , OPS DAC outboard, CMB Beta, Novarossi and even Picco P5 . All my motors like this plug .
Just FYI

Alex

 

[Grimracer]

Kris, Pinch test the low speed.. there are a bunch of videos on that out there. (it will get you close)

Over last number of years I have been using the OS#8 plug in the motor.. (wont be switching anytime soon!)

Grim

 

[Alan Elzer]

Never had one until now! Its hanging one the back of my G30! I wanted to know:
What percentage of nitro is good to run it on? It will be raced!
Whats a good prop to use?
What do i use to lubricate the flex shaft? I see a fitting on the right side of the lower unit, so i assume thats where the lubricant goes!
Any other advice would be greatly appreciated! thanks!

Run 60% at least with anyones factory blend of oil, we found years ago with 2 identical boats, props & motors that 50% sags coming off the corners & 60 doesn't. These were tested with k&B 21's on the tri-star hulls & I did the props so I knew everything was the same. Props a 40x52 (2) blade or X437/3 let it wind up you'll be fine.

 

[Brian Sorgente]

Never had one until now! Its hanging one the back of my G30! I wanted to know:
What percentage of nitro is good to run it on? It will be raced!
Whats a good prop to use?
What do i use to lubricate the flex shaft? I see a fitting on the right side of the lower unit, so i assume thats where the lubricant goes!
Any other advice would be greatly appreciated! thanks!

Looks like folks have you covered on the other stuff. As for flex shaft lube, go to your auto parts store and get one of those little thumb pump oil cans. Clean it out and fill it with straight castor oil. You can find it at pretty much any pharmacy, which is really convenient for this. People will tell you all sorts of oil mixes but this is simple and has worked great for me over the years.

On the OS lower I put a short piece of water tubing on the side nipple that extends about an 1/8" or past the end. That's so you can push the nose of the oiler into the fitting and seal it while you're pumping without making a mess. Pump it in until you can feel some light pressure and its ready for one run on the water. If you do this every time your flex and prop shafts will last a very long time. I also fill it at the end of the day to keep them from rusting inside. If you don't like the oil can, you could also mount an oiler to the side as well.

Brian

 

[Bill Gibson]

Kris, Pinch test the low speed.. there are a bunch of videos on that out there. (it will get you close)

Over last number of years I have been using the OS#8 plug in the motor.. (wont be switching anytime soon!)

Grim

Mike i believe thats the plug i use in my O.S. .32 Heli engine for my Concept DX!

 

[Bill Gibson]

Run 60% at least with anyones factory blend of oil, we found years ago with 2 identical boats, props & motors that 50% sags coming off the corners & 60 doesn't. These were tested with k&B 21's on the tri-star hulls & I did the props so I knew everything was the same. Props a 40x52 (2) blade or X437/3 let it wind up you'll be fine.

Thank you Alan!

 

[Bill Gibson]

Looks like folks have you covered on the other stuff. As for flex shaft lube, go to your auto parts store and get one of those little thumb pump oil cans. Clean it out and fill it with straight castor oil. You can find it at pretty much any pharmacy, which is really convenient for this. People will tell you all sorts of oil mixes but this is simple and has worked great for me over the years.

On the OS lower I put a short piece of water tubing on the side nipple that extends about an 1/8" or past the end. That's so you can push the nose of the oiler into the fitting and seal it while you're pumping without making a mess. Pump it in until you can feel some light pressure and its ready for one run on the water. If you do this every time your flex and prop shafts will last a very long time. I also fill it at the end of the day to keep them from rusting inside. If you don't like the oil can, you could also mount an oiler to the side as well.

Brian

Thanks so much Brian! I just happen to have a full bottle of Sig Castor oil somewhere in my shop!!

 

[BruceHartmann]

Mike i believe thats the plug i use in my O.S. .32 Heli engine for my Concept DX!

I use #8's in all my helis and 2 stroke planes. Haven't had one go bad on it's own in years. They only go bad when I plug them into the 12v side of the power panel.

 

[Bill Gibson]

I use #8's in all my helis and 2 stroke planes. Haven't had one go bad on it's own in years. They only go bad when I plug them into the 12v side of the power panel.

Ha ha! Bruce, I’ve done the very same thing more than once!

 

[Tom Foley]

Most of all Bill ..
HOLD IT WIDE OPEN!!!!

 

[Bill Gibson]

Most of all Bill ..
HOLD IT WIDE OPEN!!!!

OK HIPSTER! Will do!!

 

[FloridaScaleBoater]

OK HIPSTER! Will do!!

No he won't Tom,,,
He's telling a story!