Revive a Mariner 90 horse outboard

I bought a boat which has been sitting in the yard for a few years. At least, after some
effort, which is just repeated cranking, boost charging battery and cranking, it started and sound pretty good, so I bought the boat. I installed a new marine battery, new set of plugs since. All of these are 2 weeks ago. I am still cranking, in vain. Any suggestion will be appreciated.
shinn

Do a compression check first make sure u have at least 100 PSI on each cylinder maybe higher and all cyinders are within 10 PSI of each other to make sure you don't spend money on a shot motor.If all checks out. clean preferably rebuild Carburetors.And check spark to all cylinders,Let us no the outcome,GOOD LUCK.

Definately rebuild the carbs and check the fuel pump,hose and primer bulb.

Ha-le-lu-ya (sp?) I got it going!!! After all, it did start before I paid for. The funny part is that, when I opened the engine, I FOUND 1 of the 6 plugs was not connected, and ALL the plugs were "finger loose". Not even all the way in. Despite of that, it started before. Battery has got to be replaced, no question about that. But, not knowing how to choke a cold engine, and not knowing how to pre-set the throttle such as half way or 3/4, the motor was sluggish to turn, even with a new battery. And get pretty hot after quite a few crankings -- I decided the weakness is in the starting motor.
So, after I posted the thread, and lost some sleep, I decided to play a little trick with the batteries.
First, I parallel the new one and the old one, (I kept the old one), and the battery trickle charger, to get more cranking power. It helped a bit, still sounds like - wow-woow-wooow... THEN (do not do this at home unless you have enough electrical background) I series 2 batteries, providing 24VDC for starting motor and 12 for other part of boat circuits. It cranked better! After a few rest and try, including spraying carburator cleaning liquid, and juggling with throttle, and choking, it finally started, and run and run. Ha-le-lu-ya.
Thank you guys for calling my attention to the carburator rebuilding, which I don't know much,
I guess I will have to, quickly. I didn't hear the choke clicking, rebuilding will certainly help.
I need to rest for today. That was enough excitement.
Shinn.

Happy to see you figured it out.Still rebuild the carbs ,with it sitting that long without running.Carbs most likely have some build up in them. Carburetor problems are one of the top causes of blown motors.

Thanks, vane. rebuilding the carbs - is it just to take it out, and clean it with kerosine and put it back? Will it involve gasket?

Get a kit for each carb, it will have all the gaskets you need. Clean with carb cleaner, with the little straw. You might want to have a container
to catch the overspray, as you might want to soak parts overnight anyway. Make sure all the little nooks, crannies, tubes, vents, everything
gets a good blast. Its a dead horse, but if you're gonna keep the engine, get a manual, you can also search, "carb cleaning" on this site.

Thank you much, emac:
I should get a manual. But why do u call it a dead horse? I've had an older motor and
ran like a top. And, sorry for language problem; when you said 'give it a blast', is it about the boat or a good air blast after the clean job?

Man, you are really lucky not to have fried any electronics with that 24 volts stuff!

Jeff

the dead horse is that everyone should get a manual. The "Blast" is the spray from the straw. theres lots of little holes, they all need to be cleaned out.

Like I said; keep the "other" circuits on 12 VDC, only the starter motor get 24. Motor gets a lot more cranking power
with less current, therefore less heat. I should get the starter fixed, wither brushes or whatever. But the trick started
the motor.