35 HP Evinrude from 1981, Q's about lower end oil, prop, plugs

[MXHalofan]

Hey boaters, been loving my old toon and reading on this awesome forum quite a bit. Want to keep the outboard in good shape so I have some questions.

My prop has some slight damage. Looks like it's aluminum and has some major scuffs from the previous owner. Doesn't shake while at WOT on the water. I'd like to know if I am ok to use it more. Also I saw a couple letters on it by the shaft area, is that how I ID it?

Like to know how to top off the lower unit oil. There's two screws that look like drain and fill. Do I just top it off to the upper screw hole?

I had to pull off the carb for cleaning and the air/fuel screw got twisted some. Is it ok to run this engine for the rest of the season without hooking up a tach and doing the proper adjustment? Engine starts and runs out great.

I installed NGK plugs and removed Champion plugs. Hows the perception of this setup? I run NGK's in all my other 2 stoke engines but this is my first boat. Thanks boys

[oldcatamount]

the numbers near the prop shaft refer to the size of the prop (pitch and rake) and that is how you would identify it should you need to replace it. It's also a "right hand" prop meaning that it turns clockwise going forward.
What do you mean by air/fuel screw? I hope you aren't talking about a needle valve but if the motor runs good as you say, it's probably ok for this season anyway. Recommended spark plugs are Champion plugs, but if you are having good luck with NGK, keep using them. (If it ain't broke, don't fix it)

[Al-53]

your better off if your going to top it off to just refill the whole lower....that way you can check the condition of the unit..see if water is getting in and if any metal....also when u do it make sure you replace the plug seal washers....they are a 1 time use item..they seal on compression....

OMC motors were designed to run best on champions....I had NGK's in my boat when i first bought it.....ran good...but when I changed over to champions..I did notice a difference...ran smoother....

are you talking about the needle screw on the front of the carb....if you bent it..I would eventually replace it....u dont want to score the orfice it seats into....

Al

[MXHalofan]

Now that you mention the plugs, I do think it was running better on the champion plugs. Thanks guys

[Rick.]

Nice to hear form someone who's motor is running fine. LOL. I would replace the lower gear oil rather than top it up. Then you know it's been done and when. I would also suggest you get an original OMC service manual for your make, year and HP. You won't regret having it on hand. I get them off Ebay. Best of luck. Rick.