Recommended 4-stroke PWC engine...

KX6D

Seaman
Joined
Aug 23, 2010
Messages
63
Greetings to the professionals out here!

I'm planning to build a boat and would like to install a 4-stroke jet out of a PWC.

Something like this...
Jet Powered Glen-L Squirt built by David Streeter - YouTube

Who makes the best 4-stroke engine? Yamaha? Parts seem plentiful!

What is the smallest 4-stroke you can get?

What engine would YOU recommend?

Thanks for your input!
 

oldjeep

Admiral
Joined
May 17, 2010
Messages
6,455
Re: Recommended 4-stroke PWC engine...

Seadoo 4Tech with a supercharger.
 

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: Recommended 4-stroke PWC engine...

The Yamaha Waverunner VX is the most durable and the best selling PWC on the retail market. (I have both Yamaha and Sea Doo 2 strokes.)

But 4 stroke PWC's are not cheap on the used market.

A finished Squirt with a donor Yamaha 4 stroke would probably cost more than buying a used Chris Craft mahogany boat with an engine already built.
 

smclear

Chief Petty Officer
Joined
Jul 14, 2008
Messages
626
Re: Recommended 4-stroke PWC engine...

Sea Doo 4 Tech = Premium fuel

Yamaha = Regular fuel

Both are supercharged. Both are available as N/A versions.
 

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: Recommended 4-stroke PWC engine...

I see where GlenL.com boat kits have a section on using PWC engines and jet pumps in their boats. Jet drives are just a little different animal.

I would think they'd runbetter on a boat that has a high performance hull that you could swing the stern around in tight turns.

Let me say that the yellow 580 cc Sea Doo motors last much longer than their 787 cc (white color) engine with single rings and power valves. But neither will have the lifespan of a 4 stroke Waverunner engine.
 

JimS123

Fleet Admiral
Joined
Jul 27, 2007
Messages
7,952
Re: Recommended 4-stroke PWC engine...

I only own SeaDoo skis and that's all I would ever own for a variety of reasons.

If I was just looking for an engine, it would be a Yami hands down. Work on a SD then a Yami and you'll understand why.

BUT, if you want a bulletproof engine, stay away from anything supercharged. Buy the biggest Yami they make that isn't supercharged.
 

Fleetwin

Lieutenant Junior Grade
Joined
Nov 23, 2011
Messages
1,141
Re: Recommended 4-stroke PWC engine...

Seadoo 4Tech with a supercharger.

We own one of these. It has been very reliable. No issues whatsoever. We don't use Premium fuel. It runs fine.
 

oldjeep

Admiral
Joined
May 17, 2010
Messages
6,455
Re: Recommended 4-stroke PWC engine...

We own one of these. It has been very reliable. No issues whatsoever. We don't use Premium fuel. It runs fine.

I run nothing but premium in mine - .10 more per gallon, who cares when you consider the cost of the machine.
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,630
Re: Recommended 4-stroke PWC engine...

With the Squirt, length is a concern. Most of the jet powered squirts run the 10% extended length at 11'. I can't remember the max length, but it's tight for most larger engines. The Dyno-Jet has a little more room I think.
 

86 century

Ensign
Joined
Sep 8, 2009
Messages
986
Re: Recommended 4-stroke PWC engine...

I have been looking at the same thing to swap out an omc turbojet good luck and get out the wallet if you want a four stroke.
 

smclear

Chief Petty Officer
Joined
Jul 14, 2008
Messages
626
Re: Recommended 4-stroke PWC engine...

We own one of these. It has been very reliable. No issues whatsoever. We don't use Premium fuel. It runs fine.

Yes, it will run OK on regular fuel. But you are loosing performance when you use regular. The ECM retards the timing to compensate for the lower octane and eliminate ping. Your acceleration, top end, and fuel efficiency is all affected negatively. I can't say to what degree on a ski, but it does have a noticeable effect on my boat (same engine).

Why pay for a high performance (supercharged) engine if you don't allow it to live up to it's full potential?
 
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