Engine Replacement Advice?

[keehr22]

Thanks for the replies. Yeah, I have looked into going that route, and got a quote for around $1500 for a full rebuild from a local shop. The 12 month warranty offered by Michigan Motorz is what's tempting, no warranty for local rebuild..

Stroker kit sounds sweet, but I'm looking to stay as close to OEM as possible, for fuel economy and reliability.

[Stazi]

The stroker kit will give you more torque which should actually save you some gas as it will put less load/stress on the engine with only a minimal change in dispacement. My buddy did this in his old Sea Ray and it made a huge difference to that heavy boat.

The beauty of a stroker is the fact that you swap out the crank for a larger one which has a longer fulcrum between the mains and the big end bearings - this is what increases the torque. You wouldn't even have to mess with the carb with this change.

This is similar to the 6.3L engine you see some other manufacturers offer now i many of the other tow boats on the market.

Michigan Motorz offers a 377 as a direct replacement for 5.7's:
http://www.michiganmotorz.com/377ci-...ent-p-545.html
Direct replacement for 2000 thru 2011 5.0L & 5.7L MerCruiser carbureted applications; or MerCruiser 6.2L MPI applications.
This engine is NOT a replacement for the MerCruiser 350 MAG MPI unless the ECM is recalibrated.
Rated by MerCruiser at 320-340 hp @ 5200 rpm (actual power levels may vary depending on OEM calibration and application).

[keehr22]

That is a good point, and the extra torque would be nice for some 4 skier holeshots! But, at $4700 versus $2300, I doubt it's got 2 times the horsepower and torque of the direct 5.7 replacement.
I'm just trying to get the biggest bang for my buck, a good reliable engine from a reputable company, that way I can get the family back on the water. I think I'll just go with Michigan Motorz, unless anyone has any local references back in TN for engine shops who warranty their rebuilds?

[Stazi]

My thought was to rebuild WITH a stroker kit which is around $700-$1000 depending on whose you buy - this would be way more economical than buying a whole new donk. The reference was just to show you that it's a viable option. I wouldn't pay a $2400 premium for a stroker form Michigan Motorz, either.

There should be a engine builder in TN that could do this for you with some sort of warranty. The pull out an rebuild should be super quick, almost as fast as buying a drop in.

[viking]

Heck - Docdrs just rebuilt his seadoo in a few days. Buy him a round trip ticket, have all the parts ready, and in a weekend he'll have that thing purring like a kitten

[keehr22]

Stazi - That's a real good point. So you don't think I'll have tuning issues using the stroker kit with my same OEM carb and intake? I'll have to call around and see what I can find for machine shops that back their work, I'll spread the search out to some nearby cities.

Viking - Nice, if only it were that easy! My wife sunk our seadoo last year, I ended up doing the rebuild myself, stupid thing never did run right after, so big kudo's to docdrs! I got great compression, but wiring was messed after becoming a bobber in the lake. Wanted to get it back on the water for her, with a big sticker on the back; "Yellow Submarine"

[Stazi]

keehr22 - You shouldn't have to mess with the carb at all, except perhaps a slight adjustment of the idle mixture screws, but that's to be expected with any rebuild, due to part-to-part variation. The displacement increase is really not that much (+9.4%) so nothing the stock carb can't handle. It will be night and day when you go for that first pull though as the extra torque will be evident. You may, as I mentioned previously, be able to go a degree up or too in pitch on your prop (after break-in) if you so desire, to increase your top end speed (if that's important to you), without sacrificing your hole shot. That is of course only if you aren't going to put 1000's of pounds of extra ballast in it - in which case I would stick with the prop you have.

Knock on wood, but if I had to rebuild my motor, I wouldn't hesitate stroking it.

Like we say in Australia, "If you want more inches, stroke it"

[moombahighrider]

keehr22 -

Like we say in Australia, "If you want more inches, stroke it"

Stazi, are you an Aussie? Do you live here in the states? I have not come across to many of us that own moomba's that are Australian.

[Stazi]

Stazi, are you an Aussie? Do you live here in the states? I have not come across to many of us that own moomba's that are Australian.

Bloody oath, mate!
I'm a sandgroper, from Perth, but have been living in the Detroit outer suburbs for the last 12 years now.

[chawk610]

Bloody oath, mate!
I'm a sandgroper, from Perth, but have been living in the Detroit outer suburbs for the last 12 years now.

Ahhh... Perth, land of, "hey, lets get bit in half by a white shark!"