1974 jet drive
 

I have been around your site a couple of time over the last couple of years . It is a great source of info on these boats . I'm looking at a 1974 I/O that will be a project boat over the next year if I can buy it right . I noticed a jet drive model in the 74 catalog . Is anyone running one ? It loks like a cool boat . But I don't see a jet drive for myself . The motor on this boat has not run in about three years and I most likely will replace with a bracket . If I can get some pictures next Saturday I will post them and get you guy's thoughts .

Re: 1974 jet drive
 

Yankee, a bit confused here. Are you saying your looking at a V-20 with a jet drive ??
I nevr seen one and dont think V-20's ever had one, but I have been wrong before. Just ask my past wives. ;D
If you have any pics. of your V you wanna buy and of the jet drive, posted them. Good luck. 8)

Re: 1974 jet drive
 

Yankee, you have a Bracket. ;D ;D ;D ;D ;D
Dont get me started. ;D ;D ;D ;D

Re: 1974 jet drive
 

what it seems is that he is looking at an i/o, but saw the jet drive model in the history section, and wants to know if anybody on this site has one.

i think a jet drive v-20 would be hard because if you are not giving the engine power than you have no control over the boat. just my thought Fishbonejr

Re: 1974 jet drive
 

Hey Yank, where did you see the 74 catalog?? I don't see it on this site. I'd like more info on the jet model too. :)

Re: 1974 jet drive
 

I just checked myself and dont see it either.
Tin, is there a V with a jet drive.???
My definition of a jet drive is what you see on those wave runners...correct ?

Re: 1974 jet drive
 

i don't see it also, but there are two types of jet drives. Theres the one like on a jet ski but there is also one that is like an outboard here is a link. they dont make them that big so i dont think it is what is on the v-20 ( if there ever was one)

http://www.yamaha-motor.com/outboard...me/3/home.aspx

Re: 1974 jet drive
 

Thinking it was more on the line like this.
http://cgi.ebay.com/ebaymotors/berke...QQcmdZViewItem

Re: 1974 jet drive
 

Here is one for a yammie 150.

http://cgi.ebay.com/ebaymotors/Yamah...QQcmdZViewItem

Re: 1974 jet drive
 

I just checked the History in the Gallery...It musta got lost in the crash (or I'm crazier than I thought I was), but I was lookin' through a '74 Catalog here just the other day...Think Llabi found it and Bigshrimpin posted it...whatever...it's gone now ::) ....

Re: 1974 jet drive
 

yea i remember a 74 catalog and it had a v20 with a jet drive as an engine drive, not sure were it is but i think that if it was a jet drive that it was an outboard one because the jet drive on the jetski would be alot of trouble. the only reason you would want a jet drive is if you do shallow water fishing.

Re: 1974 jet drive
 

Will be interesting to see a catalog with a V-20 jet drive.

Re: 1974 jet drive
 

They made a Scarab jet.

Re: 1974 jet drive
 

Is that for a inboard motor or is it an outboard. ??

Re: 1974 jet drive
 

BS did tell me that the new Catalogs he posted were lost, and that he was going to have to rescan them and repost.

Re: 1974 jet drive
 

i am curious, i know i have seen other jetboats like yahamas and seadoo's but they claim that their boats with jetdrives get up on plane as soon as you hit the throttle and i have seen these on the water and they do, but my question is if you had a jet drive v-20, would it plane as soon a you hit the throttle or is it the design of the hull?

fishbonejr.

Re: 1974 jet drive
 

I've worked on a lot of the older jet drives( Berkely, Dominator, Jacuzzi) in an odd array of boats. I had worked on a neat package in a 19 Grady that had a hi perf smallblock with a berkely drive, it worked pretty good, seen some of the Chrysler boats with their own jet pump( never worked on one). The biggest problem with the jets was they needed a lot of torque to make them work( small blocks were barely enough) most of them worked better with big blocks( the jets ski's have pumps that allow a lot of slippage at lower speeds), and got their reputation or being gas hogs because of that, they are actully the most efficiant way to push a boat( they just drive weird, they even coast). Pumps are making a comeback because of the more efficiant small *diesels available, the diesels torque curve match the loading of a pump. they use them in the Northwest on comersial boats, i had a friend in NC that built comercial boats with Kodiak and Hamilton pumps

Re: 1974 jet drive
 

Fishbone, they accelerate faster then any other means of propulsion on the water, they just don't top end with prop boats because they have to maintain more contact with the water to keep water coming in the pump

Re: 1974 jet drive
 

ok but you need alot of power to do it.

another thing is that jetdrives also can get clogged and then you have no propulsion and you have no control over the v-20. enless you had the outboard then the lower unit could act as a rudder. But i think hammer and spare parts are right they had a jetdrive more like a jetski.

Re: 1974 jet drive
 

thats giving a jet ski more credit than they deserve. the problem with jetpumps is they are too efficient, as the speed increases, the amount of water that enters the inlet increases, so the pump becomes more efficient in pumping the water out, *a prop usually slips some what, allowing the engine to keep turning up. Most jetpumps will bog an engine, they require tons of torque, unless you make them slip by using lots of clearance in the pump( jetski type), that allows the eninge to rev up to the higher rpm where it makes power. Some pumps have a rudder, but it doesnt help at low speed.

Check out a Hinkley Picnic Boat( 3/4 mil 34' dayboat), they use a Hamilton Jet pump hooked to a Yanmar Diesel. The low speed handleing on these suck so bad, they incorporated a computerized joystick hooked to the pump, engine, and bow thruster, this thing came make anyone dock a boat like a pro

Re: 1974 jet drive
 

but with twin jetdrives you would also loose the ability to turn on your engines. also how do you go backwards i know on some jetskis that there is a flap that comes down over the drive but that only works on small boats. *???

Re: 1974 jet drive
 

The Hinkley is a single engine in the 34. They have a bucket that drops down over the nozzle, it rediverts the water fwd, some of the buckets pivot with the nozzlee, some of them the nozzle pivots inside the bucket, that makes the steering oposite what the wheel turns( most jet skis are like the latter). Realy confuses you when your backing. We used to take a jat boat out and run it up to 40 the throw it in reverse, it will stand it on its nose, thers no transmission, so nothing to break, however, there was this one guy who was going to fly up to the ramp and throw it in reverse at the last min to stop the boat, whe he put it in reverse, the pressure from the pump , pushed the bucket back up, doubling up the shift cable, he had his foot in it so the boat kept coming, it skidded right up the ramp. After walking around and answering a lot of questions, he got several people together, they picked the boat up, set it bcak in the water, and other than the shift cable, and a few scars on the bottom, the boat was OK

If you want to see something really neat to push a boat, check out Volvo's IPS system, I think its volvopenta.com then look for the ips icon. We sold a 42 Cruiser's express with twin 370 hp Volvo Diesels, the boat will run 41 mph( 6 mph faster than twin 420's inboard), and with the Joystick, even I can park it with having to worry about fixing gel coat

Re: 1974 jet drive
 

yea i have seen those in the boating mag they are like imboards but they are like i/o's in the same way and they pull the boat forward insted of push. there cool.

Re: 1974 jet drive
 

they drive like nothing else, that 42 footer drives like a 19 ft ski boat, the Volvo reps were telling me about a Lazzara 65(?) at the Ft. Lauderdale boat show that had four of those units in them, it would plane in less than 6 secs, and burned less than half the fuel of the standard inboard twin set up

Re: 1974 jet drive
 

just curious (i know i am curious alot) but i saw in a wellcraft thing i cant remember wear right now but i might think of it later, but it reccommended for the v-20 steplift with a max hp rating of 235 hp it said twim 115s were best, but i think that would be to much weight for a v-20 becuase a 115 weight about 350 and you put two of them on there that would weigh about 700 pounds, but a 225 ways about 450 and there is only one engine. what is a better power plant twin or single. *???

fishbonejr

Re: 1974 jet drive
 

There was a 1974 catalog in there with a jet drive steplift as well as inboard center console . The inboard had the motor mounted in the console . Yankee , as Maco Joe would say " go bracket young man " . Unless you are in a lot of shallow water , I don't think you would be happy with the jet .