how difficult to replace rings on outboard

[RobertN]

I inherited by sorts a '73 Chrysler 14' trihull runabout with a 45hp Chrysler outboard to match. I have had it out a couple of times. The hull is sunfaded, but everything works. Except... the motor.

Twice I have taken it out on the local lake. After cruising atmaybe 3/4 throttle for 15 minutes or so, it will just cut out. The first time, let it sit for a few minutes while my son and fished, and then it fired up. Second time out, did similar, but when it finally fired, it barely ran. Got it back on the trailer, and pulled a spark plug. Lower cylinder looked ok, but the upper cylinder was fouled and getting a heavy crusted buildup.

Today, I checked compression. Lower cylinder was 125psi, but bumped to 155psi after a little squirt of oil. The upper cylinder was 90psi, but bumped up to 110 with a little squirt of oil.

It would seem a set of rings is in order. How hard would it be to put rings in that 2-cylinder motor?

 

[kenmac]

I think it would be harder to find the parts than to replace them.rings/gaskets etc,

 

[zzvyb6]

It might be too late, but I'd check the water pump. Your symptoms are often caused by a weak fuel pump or worse a water pump. When you "test" the motor on the trailer without having water available, the impeller blades overheat and fracture. Then: no water pressure. and in 15 minutes it quits due to vapor lock or seizure. This leads to scored cylinder walls and lowered pressure. Also fuel pump diaphrams weaken over the years and: no fuel pressure. A hotter spark plug will clean up the cylinder if its frequent misfire due to a fouled plug. If rings are available its very easy to pull the pistons and slip new rings on. Use a ring compressor. One more thing, too much oil in the mix and/or water in the carbureter bowl will load up a cylinder, too. I presme the gas is newer than 1973 vintage...

 

[RobertN]

I just got this from a family member, who hot it last year. We don't know the history. When I have fired it, it has been water(lake or large trash can).

I have mixed Valvoline outboard mix at 50:1.

Strange thing is, first time we went out, it was running great, cruising along, and wham, it just died. Didn't want to start, so we sat for a few minutes fishing Then it was hard to get started, but it ran fine coming back in.

This time, it did the same thing, bu when it did start, I think it only ran on the bottom cylinder.

It might be too late, but I'd check the water pump. Your symptoms are often caused by a weak fuel pump or worse a water pump. When you "test" the motor on the trailer without having water available, the impeller blades overheat and fracture. Then: no water pressure. and in 15 minutes it quits due to vapor lock or seizure. This leads to scored cylinder walls and lowered pressure. Also fuel pump diaphrams weaken over the years and: no fuel pressure. A hotter spark plug will clean up the cylinder if its frequent misfire due to a fouled plug. If rings are available its very easy to pull the pistons and slip new rings on. Use a ring compressor. One more thing, too much oil in the mix and/or water in the carbureter bowl will load up a cylinder, too. I presme the gas is newer than 1973 vintage...

 

[milkman]

Did anything run on 50:1 back in '73, I would have thought it would have been richer than that, but I don't know anything about watercooled 2 stroke.

 

[zzvyb6]

In 1973 it was a quart of 2 cycle oil to 6 gallons of gas as a rule. If its not running hot, check fuel pressure. If this is a single line fuel system with a bulb to prime it, see if you can keep it running by squeezing the bulb. Also put some new plugs into it. Or, get it running on the 1 cylinder, stop. and then switch plugs. See if the firing cylinder changes with the plug. Generally, you can look right into the carb throats. See if you see a fuel spray. Might have a plugged filter. These were a metal matrix type good for water separation. Maybe its working. Ultimately you will need to determine if you have spark. Pull the plugs and hold them to the block while you crank it. Its gonna be either spark or gas. When you come to the fork in the road, take it.

 

[alchemysa]

Crappy rings alone wouldnt usually cause it to stop. It could be fuel starvation. As stated previously check the fuel pump. Also check that the fuel filter isnt blocked. (It might be a tiny mesh screen near the carby/s). Also check that you have a good spark. Start it up then alternatively pull the plug leads (using something like a plastic woodworking clamp so you dont get a shock). There are some large outboard forums on the net. I can't remember any names but google 'outboard repairs chrysler', etc and you should find them.