Out board jets

[alcan]

I need infomation on proper mounting hight and trim for outboard jet.I have a 40hp Evinrude mod# e40teesr. It's mounted on a 14ft alumaweld sled. The motor was off the boat when I bought it. Looks like I put it back were it was,but I am not sure.I went on the maiden voyage back in 1989 so I know this rig is not an unlimited hydro. I've repaired the engine, and it runs perfect. Performance is below unexceptable.I also would like to know where to get manuals for outboard jet pumps.Thanks.

 

[Terry H]

Re: Out board jets

Alcan...jet pumps are quite ineficient as compared to a prop drive. with a flat bottomed craft you will most likely get a lot of cavitation because a lot of air gets trapped under the bottom of the boat and feeds the intake, which should be mounted at base of transom or maybe 1"above. A jet pump is more suited to a slight vee configuration. If this 40 horse with jet pump is properly set up it will perform maybe like a 25-30 hp prop unit. Some of the aftermarket manuals (Seloc/Clymer) have the data on the jet pumps. Just my Thought

 

[Fouled Plug]

Re: Out board jets

Alcan, what repairs did you do to the motor? And what RPM's are you getting from it? Is it your current top speed or holeshot that's no good?

 

[alcan]

Re: Out board jets

Hi Guy's<br />Basicly I just checked it over and serviced it. I disconected the VRO in favor of mixing fuel myself. Previous owner said engine was blowen up, said he had it to a dealer, whom agreed and told him to buy a new motor. I find that hard to belive. Any way it passed all my tests. The only place I can WOT test is on the water,so I have no idea of actual rpms. I've been reading posts about test tacks. Thinking about geting one. The engine sounds as if its all there. I am not too concerned about top speed. Boat has a hard time planing if at all. It rides bow high. I tilted motor in to try and correct. Seems that the pump housing, on the port side is draging, splashing water over transom. Thats the reason I asked about mounting hight. As it sits now the front edge of the intake is dead even with bottom of boat. The back edge is about an inch or so lower. If I could get the performance of a 25hp prop job, I be real tickled. I will be buying a larger engine. Right now I gotta kill ducks and geese, oniy a couple weeks left! Thanks and happy new year.

 

[Terry H]

Re: Out board jets

This may give you some more info on jet pumps. <br /><br />Click on this link...just a Thought<br />null

 

[alcan]

Re: Out board jets

Hey Thought 1o1<br />Thank you for the imformation. This should help.I am going to try lifting the motor up a notch (about an inch) and check a few other things.Have you got any ideas as to what I should replace it with? Thanks again.

 

[hondon]

Re: Out board jets

Since you have all that spray I would suggest that you raise the motor if that is possible.Curious as to why the former owner thout it was blown.How are the vitals?

 

[hondon]

Re: Out board jets

Looks like we may have posted right over one another.Anyway your on the right track.Raise the motor and while doing it take a look at the jet impeller and liner.If either show a good deal of wear they can really effect this units performance.

 

[Fouled Plug]

Re: Out board jets

Alcan, what compression readings did you get from the motor?

 

[Terry H]

Re: Out board jets

Alcan...first you need to make sure the motor ir running properly. Then I would deal with height of intake...maybe up maybe down...down might help with steering and cavitation. Sleds are not a good choice for a jet pump installation...just a thought

 

[alcan]

Re: Out board jets

Hi Gang<br />I just came in from hunting. Had a great day.Engine ran great. I haven't lifted it yet. I moved the gas can forward, had my son sit in bow. Still a little splashing but not in the boat. Performance was better. About the motor being (all blowen up) good question? I dont know, the price was right so I jumped. Compression is 140 even both holes.<br />Thought101 Good advice! I am curious<br />about the actual revs. myself. Bottom line I need more ponies.

 

[Terry H]

Re: Out board jets

Alcan...more power is good...maybe you can find another powerhead...50-60hp. Don't add any weight tho. Seems like trimming her out to ride more level worked some. Remember the pump sucks the stern downward, you need the power to counteract that and bring it back up...just a Thought

 

[petryshyn]

Re: Out board jets

alcan, how was the hunting?

 

[alcan]

Re: Out board jets

Thought 101, powerhead swap, interesting idea. I don't belive I have any parts catologs that recent for OMC. I run out at about 1985. I seldom get to work on (new stuff). I'll do some home work and scroung around. Power to wieght is a concern. I was thinking of a 55 to 65hp, possably three cyl. <br />Schematic, Son got 2 green heads I got 1 pintail drake and no geese. Not much fling, not much shooting, we just had fun! Have a good new year gents.