Jet Conversion?

[Stoisy]

Hey all,

Anyone have experience converting an outboard from prop to jet? I've got a 2015 40hp yammi and am wanting to convert to a jet lower unit for use in rivers.

Any advice on who to talk to would be appreciated.

Cheers

 

[SteelyDan]

Where do you live

 

[Wild Bill]

Bolt it on and go for the most part!

 

[Tightlines22]

I’ve done it before with a Merc 90. Remember tho that you’ll lose the equivalent of about 30% in hp when you convert. For example a 90hp becomes 65hp as a jet. And it’s a lot louder

 

[Canso]

Small 4stokes struggle with a jet drive, and having less then 30hp, might be good for a 14' flat or slight v style Jon boat. A slug out of the hole with your buddy and a cooler of fish on board.
Also, you will need a jack plate if you plan on swapping back and forth, but honestly, not worth the effort.

 

[Stoisy]

Live in Vancouver. Motor is in Nanaimo. But willing to take it anywhere if need be.
We are looking at the Stryker Hunter 420 Jet, so it has the jack plate factory installed.
Looking to use it on some smaller rivers potentially, so the prop isn't an option.
@Wild Bill where can you purchase the lower unit?

 

[Charter Tofino]

I looked into doing something similar to one of my old setups. There are a number of companies out of the states that offer leg conversion kits. If I remember right it was in the $2000 range.

Love those little tiller rigs for small systems.

 

[Sentinel]

As far jet pumps for OB’s go San Leandro ob jets are the 1 and only option. Your closest dealer would be West Coast Marine Services in Bellingham WA.

 

[bones]

Buddy had a 25hp merc, like wild bill said bolt it on. To negate you power loss and chop rocks put an aftermarket impeller in it.

Used a jack plate to lift it to the required height. The 25 with 2 guys in a 14' Lund would shoot 3-4" of water. Would smack an odd rock once in awhile

 

[finaddict]

Yeah I converted an old Hewie 185 River runner to jet. Was powered by an 89 Evinrude 110 and for that motor the conversion was an R40 leg. The key for any conversion is to properly re-positioning the engine height on the transom so the leading edge of the jet foot is 1/4 " below the stern hull. A 4 to 8 degree dead rise at the stern is preferable. The dead rise is needed to push all air sucked under the hull to the side of the hull by the time it gets to the stern and not through the jet intake.Flat bottoms will cavitate too much and anything > than 8 degrees will leave you too deep in the water. t The original owner had cut the transom to fit a prop leg so I had to raise it back up again. Also had to add a 1/4 full transom plate across the stern.
Here's a few photos;

 

[SteelyDan]

Try calling cascade supply and marine in chilliwack. They deal with a ot of outboard jet pumps.

 

[Fins -n- Skins]

^^^^ What Steely said.. Also check with Port boathouse they outfitted a lot of sleds and zods.