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School me on MR1 differences

veedubtek

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Hypothetically speaking, if one were to acquire a non-HO boat that needed an engine, what is compatible? What is the differences between the 110/140/160hp mr1's? Are there more revisions than those 3? Can items be swapped around from one to form another? Can you swap a non-ho boat to HO motors, and if so, what does that entail? I apparently didn't know what I thought I knew, and that needs to change. I'm sure I've seen different snippets of info in various threads, but I'll be darned if I can find it now, and google keeps leading me other places.

P.S. - I have a feeling I'm gonna need @itsdgm amongst others on my speed dial in the very near future...
 

swatski

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I know @Bruce put together a compilation of the MR-1 versions with power ratings etc.
Can not find it...

--
 

robert843

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Hypothetically speaking, if one were to acquire a non-HO boat that needed an engine, what is compatible? What is the differences between the 110/140/160hp mr1's? Are there more revisions than those 3? Can items be swapped around from one to form another? Can you swap a non-ho boat to HO motors, and if so, what does that entail? I apparently didn't know what I thought I knew, and that needs to change. I'm sure I've seen different snippets of info in various threads, but I'll be darned if I can find it now, and google keeps leading me other places.

P.S. - I have a feeling I'm gonna need @itsdgm amongst others on my speed dial in the very near future...
My question is the block cracked? If not could you not just rebuild the one you got?
 

robert843

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What year is yours again?
 

robert843

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veedubtek

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Seen, read, and pondered that. Still haven't ruled it out.

If I knew mine was a good core, I would rebuild. I'm very, very skeptical though. We'll find out soon enough
 

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zipper

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Jgorm

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I'm pretty deep into my mr1 non ho that had low compression, but i vote to keep all the mr1 variant info in one of the above linked threads. I have a thread i started with lots of details on rebuilding.
 

veedubtek

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The problem is, nothing addresses any particular real information. What's the real differences? Where's the extra 50cc's from? Will an HO run on a non HO with reduced power? Whats the deal with the 110's? What is actually interchangeable? I'm looking for some real field knowledge here as I'm about to tear down 2 of them and I suspect neither is rebuildable. I also suspect I'm not going to find the information I'm looking for and will supply it myself later.
 

itsdgm

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The problem is, nothing addresses any particular real information. What's the real differences? Where's the extra 50cc's from? Will an HO run on a non HO with reduced power? Whats the deal with the 110's? What is actually interchangeable? I'm looking for some real field knowledge here as I'm about to tear down 2 of them and I suspect neither is rebuildable. I also suspect I'm not going to find the information I'm looking for and will supply it myself later.
All of my experience is based on removal and complete tear down of the 110hp MR1 engine. My knowledge of the 140/160 engines is based on what I’ve read here.

I haven’t actually verified this, but i believe the additional 50cc is from using a different crank.

One thing that i did when i verified that my replacement engine from a WaveRunner would fit in my boat was to match each part number from an online parts supplier. In my situation i discovered that the block, crank, output shaft, valves, head, and exhaust cams were all the same part numbers. I did however discover that the intake cam had a different part number. I decided to go ahead and transplant the entire engine as it was and see how it performed. After a few seasons, it does perform well. However, there is a very slight, but noticeable difference with that intake cam at idle. But by no means worth removing the cam and swapping it with the original. Not that it would be a difficult job, but it would also require re-shimming the valves on that side to match the new cam. IMHO, it wasn’t worth all that effort.

Anyway. I do have an engine removal guide for the non-ho 110hp engines if you’re interested. But I’m sure that’s the least of your worries at this point. Good luck with your decision. I’ll be following this closely if you decide to go forward.
 

veedubtek

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All of my experience is based on removal and complete tear down of the 110hp MR1 engine. My knowledge of the 140/160 engines is based on what I’ve read here.

I haven’t actually verified this, but i believe the additional 50cc is from using a different crank.

One thing that i did when i verified that my replacement engine from a WaveRunner would fit in my boat was to match each part number from an online parts supplier. In my situation i discovered that the block, crank, output shaft, valves, head, and exhaust cams were all the same part numbers. I did however discover that the intake cam had a different part number. I decided to go ahead and transplant the entire engine as it was and see how it performed. After a few seasons, it does perform well. However, there is a very slight, but noticeable difference with that intake cam at idle. But by no means worth removing the cam and swapping it with the original. Not that it would be a difficult job, but it would also require re-shimming the valves on that side to match the new cam. IMHO, it wasn’t worth all that effort.

Anyway. I do have an engine removal guide for the non-ho 110hp engines if you’re interested. But I’m sure that’s the least of your worries at this point. Good luck with your decision. I’ll be following this closely if you decide to go forward.

I'm in the early stages of preparing a thread citing most of the differences and interchangeability. Interestingly enough, from what I've learned thus far, all crankshafts are the same (aside from some early bearing differences, speaking only to the performance side of it). Surprisingly also - the 110hp engine is actually 1052cc, as is the 160. The 140hp engine is actually the 998cc motor. The 140's use a smaller bore and beefier internals to run higher RPM's, the 160's use the larger bore and stronger internals and also obviously run higher rpm's as well. There's also some compression differences. Very different to what I'd always assumed, been a fun learning journey thus far. All motors also changed alot from 04-05.

The cam difference on your engine (from 07-08MY) I *assume* was to introduce some valve overlap to lower emissions by creating some internal EGR. I haven't verified this yet.

I am not looking forward to pulling my engines, I'm still not happy that I have to, but once I have some other projects out of the way and devise a method to hoist them out, I'll get cracking on it. Until then, I'll keep learning about all the different parts and keep my eyes peeled for wrecked skis or engine cores I might could salvage parts out of.
 

PaulyB

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I may have a 160hp motor available...
 

veedubtek

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Both of em locked up solid @boudin . Pretty sure they spent some time underwater.
 

boudin

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veedubtek

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Yessir. Not making any moves until teardown, unless I find a good deal on a wrecked ski or something. Even then, it'll likely be September before I tear into this mess.
 
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