Running in driveway

I've got two boats with outboards, both have problems I need to fix.
A 1990's Mariner Ninety 3-cyl 2-stroke, starts up, but then bogs and won't start again. My guess is the carbs need cleaning? Checked compression, 130, 125, and 100.

The 1989 Evinrude 150hp V6 2-stroke, only gets spark on 1 cyl.
Compression on this one is 80 on all cylinders.

Anyway, my most important question right now is how to test these in my driveway while on the boat(s). I've seen people attach garden hoses, but I don't see anywhere to do that. With the size of the motors-props, a trash can is not big enough to fit them and fill with water to run the outboard in water.
Your help appreciated.

And BTW, I've looked into buying a new outboard, $8-10K is rather expensive for boats that cost under $2k! Seems fixing these is best approach, but I don't like the 2-strokes. I've been considering replacing the engines with an automotive engine, I have a 3-cyl GEO metro motor, weighs only 125lbs, EFI.
Stock is 50hp, been told easy to get them 100hp, more with a turbo.
That is probably question for another area, but what advice do you suggest on getting a reliable 100-150hp outboard?

thanks, jack (my boats are a 1989 Four Winns Horizon 180, and 1979 HydroStream Viper)

 

There is a headphone-like device that covers the water inlet port and has a hose connector. That's the way it has been done for decades.
Modern engines have a threaded hole near the base of the engine for that purpose.

 

ok, got one

Didn't know what you meant by "headphone", but went to boat store, and got one, so now I understand.. thanks.

carb kit for the 90hp backordered till whenever..great. make my own gaskets?

I don't see any good options for getting a good outboard without buying a new one, and that isn't a good option either. Conversion to electric and run inboard motor and generator, but will add extra 200-300lbs, and not cheap either.

 

clogged carbs and missing air filter?

The 90hp was simply a case of no fuel filter, so aluminum bits stuck the floats open, and was flooding the carbs. Gaskets all good, needle and seats good, seems to run good now.

It does not have an airfilter in the airbox. Is that normal? There are maybe seven one-inch holes in the airbox one side, and 4 pairs of square intake ports on the other side. I don't see how to install an air filter? I don't see a parts listing for them, are they not used on 2-stroke outboards ???

thanks, jack

 

I'd bet you've figured out to take the prop off if your gonna run em' in a Garbage can? If not...
Those "Ears" are for sale in the nearest WalMart, boat hardware.
On my Mariner, the Needle valve will stick shut if you dont run it out of fuel when your done with it.

 

Outboards don't have air filters, so no need to worry about that part.


Compression should be within about 10% on all cylinders, the 130 and 100 difference could indicate a problem, but test it again now that its been run and see if they're closer.

Having 80 PSI on the 150hp should (could) be OK if they're even at 80, low numbers don't necessarily mean its bad or worn out and there is no recommended number from OMC on compression. Check the coils, they tend to crack and short out (very common). Move the good coil to another cylinder and see if it will get spark. The power pack may be faulty, but don't go replacing parts until you've done some testing to see where the problem is.