High rpm no thrust Yamaha AR230

[Troytwade1]

Hello everyone, I recently put my Yamaha AR230 in the water and I was getting absolutely no thrust but high RPM. All servicing shops are backed up due to covid and I want to know where to start to fix the issue myself. I looked under my boat Don’t see any cavitation and I can see the clean out plug from the bottom. However my clean out plugs are seized and cannot get them out right now. NEED HELP!

 

[Julian]

You almost certainly have one of two problems:

1. Something stuck in the pump
2. Clean out plugs not install properly or leaking.

I would normally order them the other way, but you say your plugs are stuck, so less likely they are leaking or not installed.

So that leave something stuck in the pumps. Since you can't get the plugs out, you have 2 options:

1. Lay on your back under the boat with a flashlight and look up towards the impellers to see if you can see anything
2. Pull the pumps off (this is easy and should take 10-15 minutes per pump - however - the fact that the cleanouts are stuck, may also mean your pump hasn't ever been removed too).

After you determine why you have this problem, you will want to remove the plugs and rebuild them.

Use the FAQ for links on how to remove the pumps and how to fix your plugs. And post here with issues/progress.

 

[scokill]

Definitely cavitation. Could be small twig, fishing line, piece of wood. I would look closely with flashlight underneath. I would be concerned about the seized clean out plugs. Also could be sealant around the grates underneath missing.

 

[Julian]

sealant around the grates underneath missing.

This would not result in zero thrust. Zero thrust is something in the pumps or air pull through from the plugs.

 

[scokill]

This would not result in zero thrust. Zero thrust is something in the pumps or air pull through from the plugs.

Correct. Didn't see NO Thrust.

 

[Jebinok]

@Julian could this possibly be a coupling issue?
i would pull the lanyard and have some one turn over the engines to insure the impellers are turning.

 

[tdonoughue]

Possible, just not very likely. Most likely is junk in the pumps (plus a much easier fix). So I would start there. The only way you would have a coupling issue is if the engine moved (like with the engine mount bolts bouncing out or something), I think.

 

[Troytwade1]

@Julian could this possibly be a coupling issue?
i would pull the lanyard and have some one turn over the engines to insure the impellers are turning.

Had a guy look at it and he said


Left side motor coupler is bad motor must come out to replace and repair
Exhaust seals on transom are bad
Clean out plugs are seized
Outer jet has a chip in it
Jet pump transom assembly needs taken off and resealed May need fiberglass work and resealed where the clean out plugs go threw the hull
Might be missing a few things

 

[Jebinok]

@Troytwade1 sorry for your situation, but happy you found some problems, happy that you are getting it all fixed, without trial and error.

 

[Julian]

Had a guy look at it and he said


Left side motor coupler is bad motor must come out to replace and repair
Exhaust seals on transom are bad
Clean out plugs are seized
Outer jet has a chip in it
Jet pump transom assembly needs taken off and resealed May need fiberglass work and resealed where the clean out plugs go threw the hull
Might be missing a few things

Bummer....we don't see many coupler issues at all....but they happen.

Exhaust seals bad - so the boat is taking on water???? Not heard of those going either.
Clean out plugs- this is common - you can fix yourself.
Chip in jet...probably does nothing to performance
Transom issues....post photos....sounds strange....I wonder if the chip in the jet and the transom are related.....like the PO backed into something????

 

[tdonoughue]

That is what I am thinking, actually on most of this ticket. Like backed into something hard! So hard it messed up stuff all the way up to the coupler. I agree, lots of parts here that rarely have issues, and all at the same time...

 

[Troytwade1]

That is what I am thinking, actually on most of this ticket. Like backed into something hard! So hard it messed up stuff all the way up to the coupler. I agree, lots of parts here that rarely have issues, and all at the same time...

Engines are brand new right out of the crate, only ten hours on each motor. But yeah no sure why or how the coupler is bad. The oil pressure light is because of a bad sensor.

 

[Beachbummer]

Either the coupler was bad, or something locked up horribly and the couple gave to save the engine...Engines are new....maybe an engine alignment issue aggravated the problem?

 

[Kenneth Johnson]

Hey Pardner, I made a device copied from a youtube video on plug removal. Worked great. It took about two hours. Made it out of plywood, 1/2 threaded rod, washers, and nuts. Wish I could give it to you.

 

[Jebinok]

Hey Pardner, I made a device copied from a youtube video on plug removal. Worked great. It took about two hours. Made it out of plywood, 1/2 threaded rod, washers, and nuts. Wish I could give it to you.

@Kenneth Johnson we do have sorta of a tool loan program on here. Someone made a nice set of scupper wrenches and who ever needs them has to ask, the holder hangs onto them after use and then ships them to the next guy. Kinda like paying it forward. I will tag @Julian, he knows about this more than i do.