Help Please : Running in a SC 46M Engine

AnotherLooney · Oct 29, 2002

Hi

I'm totally new to this and having a battle to obtain information. I "inherited" a very old (approx 20 year old) V-hull racing boat. The motor was beyond use, so I got a SC 46M engine and built it in.

I've been trying to obtain information on how to run this motor in properly and tuning the carb, but locally I've had no luck. The people that have the know-how seem reluctant to share info and one guy will run it in for me at a fee.

I would like to do this myself, but I need lots of information. Any input would be appreciated.

Thanx ;D :-[ ??? :- :'(

MikeP · Oct 29, 2002

I am sure we can help, just need to know where to start. Maybe you coud start with what you have tried or what you you are having trouble with. A picture is always good.

-Mike

Grimracer · Oct 29, 2002

Hit us with your best questions...comon I water dudes lets get a new boater going..

BRING IT ON..

I'll BE BACK...

Grim ;D

Ron Olson · Oct 29, 2002

Wlecome to the board! Have you replaced the fuel tank? Upgrade that and the fuel lines, etc. before you get it fired up. I have heard of these engines and that's about it but most are close to the same set-up. Ket us know more about the engine, front, rear or side exhaust and location of the carb. Start wuth the high-speed needle out around 4-1/2 turns out, crank it over until it fires. If not try leanig the engine until it does fire. Let it run rich for a while to break it in, lots of oil smoke coming out We can help you get it going and some performance tips, just don't tell the others where you got it when you blow them off the water.

AnotherLooney · Oct 30, 2002

Thanx guys

I've replaced everything but the propshaft and prop on my baby. The engine... Well, it is supposed to be a "cheapy", but in this country it is still very expensive! The exhaust is side mounted and I've fitted an alluminum OS pipe to it ???

The carb is between the flywheel and the engine.

My questions may seem a bit stupid :- ;D, but please, I'm only starting out

OK, Ron, the needle, I closed it totally, then turned it out about 5 turns. She would not fire at all. Turning it out almost fully, she eventually fired up and ran for about 30 seconds. The exhaust came loose, as I was scared of stripping the thread and did not tighten it enough. After that my glow-starter was dead, so I'll try again tonight!

By the way, do I run it in in or out of the water? ???

Thanx to all who replied

jklimpel · Oct 30, 2002

Looney;

5 turns seems like alot to adjust a (nitro) needle valve. By far, the average needle valve adjustment is between 2 and 3 turns.

Starting on the rich side of the adjustment has pros and cons. It will protect against a 'lean' runaway...which could do some major damage in only a few seconds, but you risk hydro-locking your engine. (Possibly leading to a broken or bent connecting rod)

When I get a new nitro motor, I usually begin with 2 turns, and the motor should start at an idle rather easy. Make sure it is in idle position before cranking (hold at idle)

When the motor starts, remove the glow lighter, and slowly richen the mixture until the engine dies...then turn back 1/4 turn and restart.

I also highly recommend testing/breakin in water, and if that is not possible, at least rig up some sort of water cooling on your bench.

Ideally, there should be a little load on the engine when running in...as well as either water cooling..or some good airflow over the head.

If you can't do either of the above at home, don't run the motor at WOT (obviously)..and only run it for a minute or so at a time.

Hope this helps.

AnotherLooney · Nov 1, 2002

Hi peolpe

Did I say/ask something stupid ???. I've only had the one reply! :-

Any an all suggestions (of the possitive kind

) will be greatly appreciated. The more the better.

Thanx

Hammerhead · Nov 1, 2002

Hey looney! Thanks for the message! I would luv to help you, but I don't know what an SC is. Who makes it? Where is it made?

Post a picture of it!

One comment. Use lock tite. If you don't you will lose your parts when you are running it.

Hammer

MikeP · Nov 2, 2002

Looney,

I think the lack of response is probably because Jeff K covered it pretty good. If he was incorrect or out in left field there would of been some replys.

-MikeP

AnotherLooney · Nov 4, 2002

Thanx all

Jeff K, i followed your advice. My glow lighter was faulty :-[ to start off with. After replacing it, my baby started like a dream 8). I knocked a dropper into the ground both sides of our pool to which I secured the front and rear of my boat with thick fishing line. Even at idle she want to run away! Is it normal at the start of breaking in that the engine sounds somewhat erratic? ???

Hammer, Loctite did the trick with the exhaust. :

Should have thought of that myself. I've been digging for info on the SC, but all I could come up with is that it's a Super Custom with the specs: "7.49cc engine, bore - 22.25, 19.28 stroke, RPM - 2,000-17,000, power - 1.18@16,500". Only a few UK sites sell this engine, as far as I could find, for around 70 pounds. My digital camera is stuffed, but I managed to get a picture from the web.

Thanx again to all

AnotherLooney · Nov 4, 2002

OK my picture did not attach ??? >

:-X

Let's try again.....

jklimpel · Nov 5, 2002

Looney;

Your engine is probably running a bit rough because of the needle mix being rich. Running rich is always better for run-ins.

Alternatively, you may have bad gas. (Nitro/Alcohol fuel is extremely vulnerable to moisture)

If it is merely a carb adjustment problem, a 1/4 - 1/2 turn of the needle to lean should resolve.

Hope this helps.

AnotherLooney · Nov 6, 2002

Thanx Jeff

Will try that. My @#$%& starter belt broke, the second one :-X :-[ >

I cannot seem to find a decent quality belt in this country!!!!! :-[

Any suggestions ???

Any comments on the specs of my engine?

Looney.......

jklimpel · Nov 6, 2002

Get a 3/4" strip of leather..about 2 feet long ...Tie a knot in one end.

You may need an assistant to hold boat down.

Loop the strap once around flywheel (twice at most) leaving a 1" 'tail' sticking out from under loop. Tighten loop. Make sure piston is in power stroke. (piston on its way down in chamber...just past TDC) Prime engine with a couple of drops of fuel down carb. Pull your knotted end hard.

...away you go.

Make sure you don't try and start your engine backwards accidently or you may damage your flexshaft. (the engine wont start either)

AnotherLooney · Nov 7, 2002

Hey Jeff

The engine is still very tight, so it's not that easy to start by hand. I especially bought a quite expensive starter to mike life easy, but I cannot seem to find a proper belt to use. I've seen on some of the sights that a kevlar reinforced belt is available, but with the exchange rate the way it is, it's not really worth my while getting one. The Rand is worth crap in this country and even less elsewhere.

I'll keep looking around here :-[ Thanx anyway.

Looney

Propjockey · Nov 7, 2002

Have you tried a sewing machine belt? Round rubber 'belt', about 1/4" dia.

Not sure how long it will last, but the price is right.

AnotherLooney · Nov 11, 2002

Thanx

Found a smallish washing machine drive belt at a bargain. It is a lot tougher than anything else I've come across up to now. Sewing machine belts are very expensive here as they are all imports. My country sux :-[

It's the most beautiful country in the world

, but the economy is up to .......... :

:-[ :-X :- :'(

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