Just aquired an old super 10 from a friend. It had been sitting in a basement for who knows how long. Opened the top and clean as a whistle so I put a little mix gas in and it actually started on the third pull. Finally found a tank that would work and got her up and running. 3 Questions: Is 24:1 the proper mix? What could make it run rough at low rpm(high rpm it runs great)? Are these motors known to be noisy? Not knocking or pinging, just really loud exhaust. Great site here. Thanks in advance!

Today's outboard motors are quieter than most pre 1960's motors especially the larger motors. As power of outboards increased so did the noise level.Baffels in air intake, "blankets" inside cover,thru the hub exhaust systems and rubber mounting only started to appear on outboard motors in the mid 1950's...well after your motor left factory.
It is also not uncommon for snout of exhaust housing to be hacked off and/or exhaust relief holes to be bored out to a larger size. These modifications may or may not increase speed but they certainly do increase noise level. There is also a gasket between powerhead and exhaust housing that may be missing or defective which might make things a little loud. There may be issues that can increase the noise your outboard makes,but, bear in mind they were loud (by today's standards) when new.
Note: some kinds of noise may indicate a mechanical problem...we hope this is not your situation.

Clean the carburetor and see if that smooths out
low speed performance.
Fuel Mix 6 ounce of Quicksilver engine oil to gallon (128 ounce) of unleaded gasoline. 6/128= 3/64 or about 1/22...use best quality TCW3 oil at a consistant ratio and adjust hi and low speed needles
to best performance...once set should run same each
time you use.
As you use a motor coming out of storage expect some
issues to arise and deal with them. Impeller in
water pump may be iffy so watch temperature of
powerhead carefully, gearcase may take in water
if seals are worn out and other items less serious
although perhaps inconvenient.
Louis

Thanks Louis! Ill try cleaning the carb and check the gaskets. There is also no air filter. Is that right?

Even most of today's outboards don't come with air filters. They just aren't needed on water where dust isn't an issue. Defiantly check the gasket where your exhaust transfers from the power-head to the exhaust cooling manifold. If that gasket is broken or compromised that will make things awfully loud for you.

Wizard WJ7 is based upon Kiekhaefer Mercury Mark 20
powerhead on Kiekhaefer Mercury KG7 lower unit. A very
strong combination.
It is good that your WJ7 came out running without major effort. Long term you should plan on some
preventative measures. A timely investment of time,effort and a little money may
head off some game ending issues.
Items that deteriorate over time with or without use:
1) electrical : coils,condensors, wiring
2) rubber/plastic : impeller,seals,handles
3) rust: bearings, bearing & seal journals,
4) lubrication: driveshaft splines and gear case
As a general rule outboard motors were designed to
last about ten years and give about a thousand hours of service. Few of our 55+ year old outboards have
seen a lot of hours so most issues are due to deterioation in storage
Louis

Running in a metal tank or any drum will amplify noise. With the amount of oil you are using I expect there is a lot of smoke, which will cause the motor to run poorly, especially at low rpm. Use a fan to blow the smoke away from the carb. Motors always adjust better on a boat than in a drum, in my experience. That's a great motor-lower unit combination- the best of both worlds. Enjoy. JW in Dixie

At risk of chewing on this subject to excess...a few
more thoughts.
Look at the fasteners holding powerhead to exhaust housing and the fasteners of manifold to cylinder block...it is not uncommon for one or more of these
to have been "pulled out" of the aluminum threads
and not repaired properly or at all. A possible source
of excessive noise.
On the subject of seals...after 60+ years seal replacement is long overdue. Plan an off season
mechanical project or having unplanned downtime
sometime. A tear down and rebuild to check bearings,
crankshaft and replace seals is within ability of
average person. It does require a press and some
work arounds to make up for lack of Mercury Service Tools. Or you can run it till it quits and park it.
It seems to me that pre 1960's outboards that have
been long stored will need seal replacement while
later models which are likely to have seen regular use (and perhaps more modern seal technology) are
less likely candidates for immediate surgery.
an opinion with no cash value.
Louis

Thanks for the responses. After messing with the mixture screws I got her running pretty well. One more fast question. Has anyone done the mikuni pump mod on this motor. I already got a pump for it and was just wondering if there was anything I should be aware of before starting.

I made this modification on a 1954 WJ7, that was in storage a long time like yours. I added a Mikuni Fuel pump by attaching it to the existing hoses. I added a longer piece of hopse. Without the motor in front of me, (at cottage) I can't say which hose I hooked up. There is a outlet on the side of the motor that looks something like a fuel pump. One outlet pulses(pumps) air, and that is rhe hose that pumps the Mikuni fuel pump. I used a Mikuni fuel pump from a large engine tractor. Exact fuel pump you can find on ebay for $20-$30. The other hose goes from the mikuni pump to a fuel line connector for a modern tank. The other hose runs from the other hose outlet on the motor to the third outlet on the mikuni pump. @ outlets on the motr; 3 outlets on the pump. You can custom attach the pump. I have mine hanging just below the cowing(stays cooler). This is where the new type gas tank connector hooks up to any modern tank gas line. My gas tank is the same for both my modern Merc, and my 1954.