Outboard Jet to Prop Conversion

[Doug from Anchorage]

I'm looking for advice from anyone who "converts". I just bought a new (2001) boat (my other one got totalled when a guy rear ended me on 20 mile river bridge) and it came with a Honda 90hp jet unit. I bought a new lower unit & prop to put on it. My questions are: When a jet unit it put on, is is normal to remove the shift rod? Is the water pick up tube the same for both? Are there any adjustable jack plates that can give 8-10" of vertical adjustment?

 

[Eggy]

I convert my Honda

I convert my Honda

Doug,

I switch between lower unit and jet unit on my Honda (200 hp). The shift rod on mine does come down with whichever unit I'm pulling. The water tube is different. The original tube is cut and a hose installed on the lower end. This is because the water pump on the jet unit is higher than on the lower unit. When installing the jet unit, the pipe goes directly into the water pump. When installing the lower unit, the rubber hose on the cur pipe goes over the piece of pipe that was cut off. Keep in mind that when the jet unit is installed, the motor needs to be mounted 5" higher on the transom. Bay Manufacturing sells a spacer kit that mounts between the case and the lower unit to put the cavitation plat on your lower unit in the correct position. Honda may also have parts available if your motor is offered in a 25" shaft length (XXL). Also, if you contact Outboard Jet Specialties, you should be able to get the literature for installing the jet unit on your motor which would include info. on how to modify the water tube, etc. This company is the only company to make jet units for outboard motors. If you have any other questions...fire away

 

[AKmud]

power lift

power lift

as far as a jack plate goes, Power-Lift has a couple of nifty models. I have the manual version (much less $$). It has two bolts on each side that hold the adjustment then there is a jack screw that goes from top to bottom to make the adjustment. Simply loosen the side bolts then run the jack screw up or down to adjust the motor height. Once it is where you want it, just tighten up the side bolts again. They also make a power version of this which my buddy used to have. It works really slick, but is expensive. I think Cabela's carries both versions if you want to check them out.

Here's a link where they test it out -

http://www.boats.com/boat-articles/New+Products-137/Jack+It+Up/10451.html

 

[Eggy]

Any Problems?

Any Problems?

AKMud...I was steered away from a jackplate by Wooldridge. they say using one gets the jet shoe too far from the transom which may cause cavitation issues. Have you had any problems? We did put one on my father-in-law's boat. His had a plastic plate that attached to the jackplate which was flush with the bottom of the boat that was supposed to alleviate most of the cavitation issues. I haven't run his boat, but he hasn't complained about anything. He only runs a jet for a short time in the late fall, so even if there sere some problems, he would probably live with them for that short period.

 

[AKmud]

mines on a prop

mines on a prop

My buddy who had the power model was using his with a 140 prop and jet using the lift when he changed units. Mine is on a 70 prop and we haven't moved it for years. I never heard any complaints from my friend and I went on his boat a few times with the jet and didn't notice any problems.

I would imagine the only time it would be a problem would be in rough water or when you are turning sharp. Either condition is quickly remedied by lowering the unit when the problem arises (which is as easy as using power T/T). He did tell me he adjusted it up as far as he could one time while running back from the Deshka, just till it cavitated then dropped it back down slightly. When he put it on the trailer, the bottom of the shoe was 1/2" above the bottom of the boat.

I think with a jet unit I would go with the power unit so it can be adjusted on the fly.

 

[Doug from Anchorage]

Thanks for the Info!

Thanks for the Info!

I'll check into the adjustment plates.

 

[alaskamokaiman]

Check out this for your jet problems

Check out this for your jet problems

Google jeteze this might just work.