TOPIC: Help Tuning my Flying Scott 60

I put the lower back together today and everything went quite well.

First up was the circulation test. Home Depot sells a Scott McCulloch hose attachment (aka high pressure spray nozzle) that fits into the water inlet on the motor. I shoved this in the hole and turned on the hose faucet. Water filled the cooling system and a nice tell-tale stream came shooting out of the port side of the motor.




The biggest challenge in the reassembly was keeping the roll pin in place while reassembling the water pump. My solution was a dab of clear silicon. After it setup it held the pin in place while I put the impeller back on. I reassembled the layers in reverse order and installed the bailer new impeller finishing it off with my home made electrical tape insulators.




After everything was back together I refilled the lower oil. The lower takes about 15oz and I pumped another 10oz in until it started flowing clean out the top. The old lower oil was dirty!


Then I replaced my plug wires with old-school solid core wires and fired her up. There was a little drama with the plug end terminals. The OE Plus wire set has a "universal" plug ends that can be put on straight or at a 90 degree boot. The issue is the plug end is too long to clear the cowling. So I took the plug ends from the Accel kit which are as short as you can get and used them on the OE Plus kit. So you will see in the last photo of the motor black wires with red boots.

First assembly with plug ends that are too long.

The fix was to use the Accel plug ends.

I have great water circulation and a nice strong tell-tale (that you cant really see in the picture but its there.)


Tomorrow I'm going to check the ballast resistor and double check the timing and maybe take her out for another test.

Now that looks like a strong stream of h2o. Nice job!
now when you go out for your test drive, if it still falls flat on its face I would suggest backing off the wot timming a small bit at a time, my first McCulloch I built did just that, it would run strong up to about 3/4 throttle and then sound anaemic and loose that feeling of power, I thought it needed bigger jets.....I adjusted the wot back untill it sounded and ran great. Good luck and please keep us informed on the drive!

Unfortunately, no test drive yesterday... and we are out of town next weekend so I'm pushing back the test for a couple weeks. But I'm optimistic!

Timing Question:
I went through the timing procedure again:
(1) In neutral, I made sure the roller was was at TDC on the spark advance cam.
(2) At full throttle I made sure the roller was ~1/4" from the end of the spark advance cam.



However, when I put a automotive timing light on the motor (not the timing light you see here in the illustration, but the kind that you connect to the #1 plug wire and point at the flywheel while the motor is running.) At idle, my TDC mark is visible almost 3/8" before the pointer. At full throttle the 31 deg marker is about a 3/8" before the pointer.

Is this motor way advanced? There's not that much adjustment in the spark advance cam. Is there something I'm missing in the equation? Could my timing belt be one (or two) notches off and would that advance my timing?

On adjusting the WOT:
Is that the Throttle Advance Screw setting? If yes, I assume the idea is... with the controls all the way forward this allowed the carbs to open past their optimum position.

So to adjust the WOT you back the screw off to limit the opening of the carbs, is this correct?



I really appreciate your encouragement and insights, I'm learning a lot. Thanks!

lol....now Im going to have get my book out and look again....lol, if I remember you do this with out running the engine, at max advance their lookin for the spark to jump at the 31 deg mark, and this was done with leaded fuel with no ethenol, I would back it down to 25 deg or so. too much advance will burn off the piston tops..witch is not good! where are you? state that is.

I'm in California

On further reflection... this weekend I'm going to check the position of the distributor pulley relative to the TDC mark on the flywheel. My guess is my timing belt may be advanced one or two teeth on the pulley. This would essentially dial in some "mechanical" advance.

Often when I turn the key, the motor will go 1/2 a turn and just stop and the starter disengages. It's feels like I'm out of battery. But with the plugs wires off the starter/battery spins the motor as would be expected.

If I am too advanced this will cause the cylinder to fire before the piston reaches TDC and I believe this could stop/hinder the motor from turning over. Getting rid of the extra advance should help the starting. Also if I'm way too advanced, under load it would likely make the motor die out. (Maybe explaining my problem on my first test run.)



Also, I got a hold of Donald Webb (aka the Scott Guy) and he has a NOS distributor cap for me. Its the last piece of my ignition system and should complete my tune-up.

it may not line up 100% strait. just like a chrysler car engine, but you should be very close. the adjustment arm should be able to compensate.
I think your about done with this part. soon youll be flying around in style!

Wow... tonight I removed the distributor (all four screws... aka easy) and rotated the distributor rotor one notch on the timing belt counter clockwise. I turned the key and she fired to life immediately. No spinning, no pausing, no stopping, just fired right up. I put the timing light on the motor and at idle I'm a few degrees retarded (as would be expected) and I have a nice crisp throttle with no hesitation or missing. At full throttle I'm at about 25 degrees. So I should be good.

I stopped and restarted the motor several time and every time it fired to life without hesitation. As far as I'm concerned this motor is ready to fly and all systems are go.

We are going to Catalina this weekend with friends so I wont be putting it in the water until next Thursday. But I'm looking forward running it next weekend. Wish me luck!

we want pics and movies!!!!!

AGREED!!!!!!!^^^^^^^^^^^^^^^^

Special thanks to PonyBoy! Heres the maiden voyage pix...

http://www.fiberglassics.com/glassic-forums/home/main-forum/dorsett-maiden-voyage-1st-day-of-summer

Great pics! , sounds like you had a great time out there. And your more than welcome. Just wish we where 2500 mi closer so I could go for a ride!!!

Hey Guys,Can you tell me were I can get inpellers for 1960 royal scott 40,Also I am looking a 1962 royal scott 43.7 custom o/b I have the cowl..Thank's

Go to the Technical page

www.txchapter.com/

and under Pump Impellers
home.earthlink.net/~flyingscott/

All is raw data however we will clean things up as we grow and get more info posted

For help on finding any part got to the Scott Guy

www.scottatwaterinfo.com/

I believe the The 40hp/60hp/75hp impellers are the same.

I bought some NOS Sierra off the bay.

Where did you get parts from (I need all the seals) if available ???

Full Gasket Sets:
www.laingsoutboards.com/scottmcculloch.html

Don Webb also has them:
web.a-znet.com/~scottguy

Don doesn't have a web store so you'll need to call him after he gets home from work, then you'll need pay him with a money order. But he's your most likely source for all the misc parts.

the 40hp has a different size drive shaft, note the tower and the pan are the same on the 40-60-75, the lower units are different, some of the 40 hp pistons will fit the 60&75s , so with a lower and a pwr head you could switch from 40 to 75 hp with out removing the motor from the boat.