Searay svr185 diy jet seadoo 110 hp

[bernieturn]

Hi there
Never got a jet boat before due here in austria its not very common...but just got an offer for a searay hull with 110hp searay jetstuff attached.
Motor is fucked, but I wanna attach a stronger one anyways.
My question : Does it make sense to plug a stronger engine (ca 150hp) instead of the original 110ps one or do I need a bigger jet then.
Thank you for a helpfull answer ..or more
Bernie

 

[Beachbummer]

In my experience Jet boat engine repower are not easy. The body of the boat Hull pump are designed with the engine in mind.

From all the conversions i have heard of, they are done for hobby and to explore what is possible. They are never economically feasible. I saw a seadoo upgrade that included the pump and Hull graft from the donating jet ski.

I saw Mexican seadoo converted to outboards in Cancun club med.

Either same engine or other boat, unless you like a challenge and money is no object.

Everything is possible, but won't be worth it cost wise.

 

[bernieturn]

Hi Thank You for your opinion. Due its only 300 bucks and I have some td engines laying around, I think I m gonna choose the challenge.... I miswrote in my thread above ,,theres a SEADOO jet (not searay) attached to the SERAY hull....so its a bastard anyways. Even if it will perform badly in combination with the hull maybe..... would a little more horsepower (like 150 ) of an om606 300td benz machine that I ve got make a difference and improve the power created by the jet ?...or does a stronger engine always require a bigger nozzle diameter ? I m new in that technik...wanna experiment a bit...and prefer to ask before I fuck up direction complete.

 

[Beachbummer]

You may have to gear the engine/select engine based your needed target rpm. 300 hp at 5000rpm won't help you much on the jet boat. Original Max rpm is probably 6800 to 8000 rpm? (Wild guess)

If you could get some details on existing engine and/or pump that may be helpful hitting that Max rpm or above will be important for performance.

 

[bernieturn]

yes it needs around 7000rpm...My engine has 174 hp@4400 rpm ..and I can use gear box.....but I guess that will be too much and will need bigger jet probably

 

[Beachbummer]

Chain gear? New pump and new engine seems very ambitious unless it's a graft and you bring the Hull, pump and engine mounts with it. Don't forget exhaust system.

Best of luck

 

[d_coyne1984]

I have never done any jet tuning, but you may be able to repitch the impeller to compensate for the added power. That is the only difference between the pumps on the Yamaha 190 and 192's. I have heard of people boring out the nozzle a few millimeters too.

 

[bernieturn]

Chain gear? New pump and new engine seems very ambitious unless it's a graft and you bring the Hull, pump and engine mounts with it. Don't forget exhaust system.

Best of luck

Toothed belt and bit smaller engine will do fine I guess...thank you for the tips... The low price of the unit wont let me fuck up too much ...due I have Motors as well.

 

[bernieturn]

I have never done any jet tuning, but you may be able to repitch the impeller to compensate for the added power. That is the only difference between the pumps on the Yamaha 190 and 192's. I have heard of people boring out the nozzle a few millimeters too.

Yeah guess nI can repitch impeller...have looked technic up in the net.My nozzle is only 90mm..that is rather small ...isnt it ??? ..have no comparison..no/few jetboaters/jetboats around here. I dont want to win any races...just wanna make something out of that hull which comes with jet already

 

[Beachbummer]

Keep us posted on your progress, should be a fun project!

 

[bernieturn]

I will...but will start in spring...hull is in hamburg/germany...me in vienna/austria...and cant just float down the danube yes should be fun...lots of time to plan till start of project.
Thank you, have fun !