too good to be true? engine/pump for sale

[Bob0429]

Hey guys , been lurking the forums for awhile and also researching on inboard jet drives ( jetski engines) .... i found this on ebay today , doesn't this look like a ' too good to be true' , does anyone know about this jet/pump and if im missing something with this ad. Also , if it would be a really hard project to do , i have access to a shop with basically everything i need just wondering if its semi possible to do ? do you guys think there is something missing on this ?


https://www.ebay.com/itm/NEW-Marine-Jet-Boat-Engine-70-hp-w-Jet-Pump-for-Personal-Watercraft/230717209443?ssPageName=WDVW&rd=1&ih=013&category=171119&cmd=ViewItem

 

[gotmuddy]

finding parts may be hard or impossible to find. A three cylinder that is that small will rev REALLY fast. I personally would rather have a used tigershark or yamaha jet ski to start with.

 

[Loggerhead Mike]

This is just my openion being a mechanic

1. It's a remand unit
2. No warranty
3. No warranty
4. No warranty
5. It's a $1200 gamble. A lot of a- holes make a living doing basic rebuilds without the proper machining. Don't let fresh paint fool you

 

[Bob0429]

thank you , i know exactly what you mean , but even if its a new motor still not worth the chance , which they say it is but you never nowadays =/

 

[Kevin Turner]

I spent nearly $20K and hundreds of man hours in three 2SI (2 stroke international) engine/pump combo prototypes. W/O going into to great detail, the project was shelved due to a lack of 2SI factory support.

That said, the unit itself showed great promise and we learned with the correct impeller pitch, the combo performed fairly well. The biggest performace problem I encountered was hard start after shutdown. Heat soak vaporized the fuel in the carb bowls and it wouldn't restart until she cooled down.

If you're a tinkerer, it could work out for ya. I

 

[fwalker94]

Kevin, I would like to know what you found out. Im getting one from a buddy that was going to use the motor for something else and he is seeling it to me for $400 and Im going to put it in my jon boat.

 

[Kevin Turner]

Kevin, I would like to know what you found out. Im getting one from a buddy that was going to use the motor for something else and he is seeling it to me for $400 and Im going to put it in my jon boat.

All in all, they ran fairly well...when they would run. As I recall the pictured 15' boat had a decent hole shot and ran about 30 MPH. Fuel economy was great. All 3 shared the same problems; Finicky carbs, long-cold start crank time, heat soak (deadly on moving water) and fragile impellers/pumps.

 

[fwalker94]

Whay do you mean "heat soak"? Im new to the jet thing never had one and Im going to do this one on the cheep and then i hope to build me one from scratch.

 

[Kevin Turner]

Whay do you mean "heat soak"? Im new to the jet thing never had one and Im going to do this one on the cheep and then i hope to build me one from scratch.

Sorry for the slow reply...
Briefly, think of heat soak much like vapor lock. When then eng is run hard, then shut off, cooling water stops flowing, thus "heat soak"; the engine get's hotter. The heat boiled the fuel in the carbs; took about 20 minutes B4 she'd restart.

Another I found during testing was non marine wire was used in the control box. The stiffer wire(s) failed from the engine vibration.