Yamaha 242 LSE motor swap

[JetboatBrad]

Hi all, swapping out 1 of the 1.8l engines. Found a takeout that is 2 years newer with 18 hours. I had to pull the flywheel cover with the magneto to swap from one engine to the other. Had to buy the special tools to pull the coupler. I’m wondering if anyone has tried to tackle a swap and what problems you run into. The service manual calls for another magneto but I really don’t want to wait on another from Japan. It looks all good but I don’t want to be stupid. Any help or guidance would be appreciated.

 

[AboveTheBest]

I swapped a newer 242 engine into my old 190.

Its pretty straightforward and the only difficult part is swapping the couplers. Let me know what questions you have.

 

[AboveTheBest]

One thing I can tel you that’s important to pay attention to: the exhaust manifold gasket can be reused, just make sure you put it on the same side facing the engine as how it was when you took it off.
I can’t remember what it says, but there is writing (something like R6...) that I believe needs to face outward.

The whole thing was very easy, just make sure you plug it all back up the way you took it off

 

[JetboatBrad]

One thing I can tel you that’s important to pay attention to: the exhaust manifold gasket can be reused, just make sure you put it on the same side facing the engine as how it was when you took it off.
I can’t remember what it says, but there is writing (something like R6...) that I believe needs to face outward.

The whole thing was very easy, just make sure you plug it all back up the way you took it off

Ok cool. Thanks for the advice. I left the exhaust manifold pretty much intact from how it came off. I’ll double check all that and make sure I’m right. Did you remove the coupler like I had to from the engine? Or was it an exact swap? I think the engine I’m using now is from a jet ski so it doesn’t have the flywheel cover that has mounting for the exhaust manifold bracket. I had to pull the coupler to get that off.

 

[AboveTheBest]

Ok cool. Thanks for the advice. I left the exhaust manifold pretty much intact from how it came off. I’ll double check all that and make sure I’m right. Did you remove the coupler like I had to from the engine? Or was it an exact swap? I think the engine I’m using now is from a jet ski so it doesn’t have the flywheel cover that has mounting for the exhaust manifold bracket. I had to pull the coupler to get that off.

My 190 was a 2013 and it apparently had the ski coupler, so I had to swap out the coupler from the 242 engine to get it to work.
I didn’t realize it until I’d already lowered the engine in the bay and wondered why the heck it wasn’t fitting...

I ended up pulling and installing that motor 3-times before it was all said and done, and feel like could do it in my sleep.

Hopefully you made a note of which shims went where for the engine mount bolts, as this is very important to keep the same.
You’ll find torquing those things down is a major PITA, and I was doing it on a 190, a 242 is probably harder with less clearance on one side...

I had a tip from a ski repair guy regarding torquing the coupler bolt. He said the way it’s threaded if you get it hand tight, the first time you load the pump it will “torque it to spec”...

 

[AboveTheBest]

By the way, are you just swapping because this engine has less hours or is something wrong with your original?

 

[JetboatBrad]

By the way, are you just swapping because this engine has less hours or is something wrong with your original?

Yea I think I have detonation in one of my cylinders. Originally blew a spark plug out of the head. I helicoiled it and put a new plug in and it just kept frying the plug. I’m assuming that’s what’s going on in there. I’m gonna pull it apart when I get a chance.

 

[JetboatBrad]

By the way, are you just swapping because this engine has less hours or is something wrong with your original?

My 190 was a 2013 and it apparently had the ski coupler, so I had to swap out the coupler from the 242 engine to get it to work.
I didn’t realize it until I’d already lowered the engine in the bay and wondered why the heck it wasn’t fitting...

I ended up pulling and installing that motor 3-times before it was all said and done, and feel like could do it in my sleep.

Hopefully you made a note of which shims went where for the engine mount bolts, as this is very important to keep the same.
You’ll find torquing those things down is a major PITA, and I was doing it on a 190, a 242 is probably harder with less clearance on one side...

I had a tip from a ski repair guy regarding torquing the coupler bolt. He said the way it’s threaded if you get it hand tight, the first time you load the pump it will “torque it to spec”...

I was going to ask you, I know you said you had to pull it back out once because of the wrong coupler but did you get it in and bolted only to find out later it wasn’t lined up? I’ve been told it needs to be dialed in when you line it up. I’m just wondering if that will be obvious if I’m off or what. You would probably be the best guy to ask.
I swapped the motor mounts 1 by 1 with the 3 bolts that bolt to the block from the old engine so all the shims should be the same. I don’t know if I will be dead on bow/stern wise but height should definitely be ok.