Learn me Jet boats

I've somehow managed to get myself into a position where I'm looking at a jet boat project. I know nothing of Jet boats.

From the ad: 76 21' Colorado custom jet boat. Owned since 1989, No motor but comes with a good olds 403 (sure). Been sitting outside and appears interior needs some work. I offered a rusty dodge ram half ton that I have $350 in, and he accepted. (Maybe a red flag?) No motor in the boat, but it does come with the headers, which I remember being hard to track down.

Anyways, does anyone know what I should look into specifically for on performance jet boats? I'm sure it'll take some money, but I would prefer to not have a huge money pit. I realize this is a bad idea, however it still peaks my curiosity! 

Color me jealous. I've been looking for a cheap one local to me for several years. 

Unfortunately, I don't know anything about the Berkeley jets beyond I want one.

Make sure you do a build thread. 

Nice looking Colorado.  Wicked quick flat hull with just enough vee to stay planted.

I always thought it was a bummer that the de facto power was an Olds.  Anything BOP will fit if you can source the flywheel and coupling, but they chose one of the heaviest and worst-breathing GMs.  Caddy 500 is the ticket if you can afford the flywheel.  BBC headers fit if you cut them off and weld on Caddy flanges.  For a really good time, you can probably pick up a turbo at screamandfly.

That looks like a Berkeley pump.  Parts should be available including impellers to tune to whatever power you put in it.

Don't die.

In reply to Toyman01 + Sized and :

Same here. I've always kept a look out for them and they don't come up too often.

In reply to Curtis73 (Forum Supporter) :

I was hoping you'd chime in. That's good to know about engines. I was worried about the pump, but it looks like Berkeley are still in business.

If you decide not to go with the Olds engine, the GMC motorhome crowd might be interested in it.

Don't die. And get us better pictures of that sweet airbrushing.

That thing is awesome. I had a ride in one like this on the St. Lawrence when I was a kid and it left a forever impression! Congrats on the score. I don't know anything about these but it seems like many of them that are for sale are motor less or blown up. The application must be very engine intensive.

Also I am with Keith on more pictures!

Make sure the transom and rest of the hull is solid, old fiberglass over wood boats tend to suck moisture into the wood then rot from the inside out. 
Once that's done throw that olds away and put an ls in it almost immediately. 

I learned the hard way with my boat that it's better to assume the floor, transom and stringers are rotted - then prove to yourself they're not.

A good website with a mix of mild to outrageous jet boats is SoCalJetboats.com. Lots of people on their forum can help you. If you get it running and the motor seems healthy and the pump bowl and impeller seem OK - then the best upgrade at that point is a "Place Diverter". "Place" is the name of the company. 

In reply to 1SlowVW :

I've already joined the ls jet boat group on facebook!

In reply to Sparkydog :

I'm just going to assume that's the case. I have some experience with wood and fiberglass buidling a paddleboard. Hoping if they are rotten I could fix them.

I'll take a look at the website and the diverter!

Everything I know about jet boats I learned from watching Mike Finnigan:

https://www.youtube.com/c/FinnegansGarage/featured

Boat named "Bad Influence".   What could go wrong? 

I'm sure you know these are not big water boats, you need smooth straight water to get any kind of sustained speed out of them.  If set up well the boat rides on a very small section of the hull with just enough boat in the water to allow good flow into the pump inlet and impeller.  Kill switches, helmets, lifejackets with small parachutes and kevlar shorts are a thing in the faster boats.  

up here you are not a proper fisherman unless you have one of these.

And a $90,000 diesel to pull it around. But if you can swing it they really haul the mail, or fish.

Oh yeah, like 11GTCS mentioned, nowadays an 18-20 ft low freeboard boat like the Colorado is not going to be fun in a lake/river full of wakeboard boats. You need to go places where the big ass prop boats can't get to. Back in the 70's when these boats were new - they did fine just about anywhere.

Hands up anyone who remember's Relic's jet boat on the Beachcombers!

Well. I guess I'm the proud (?) new owner of a 70's jet boat. It definitely needs some work but I think it's all there. I need to go over it a little closer and put a list together. I plan to look over the "good" 403 and see how much it'll take to get it going, then pull the interior and check the floor and clean up the seats with new carpet. Lube/replace the cables and go from there. Hoping to have it on the water for next summer. In the meantime i'll have to start growing the mullet to go with the boat.

Keith Tanner said:

Hands up anyone who remember's Relic's jet boat on the Beachcombers!

Do you ever watch Finnegans Garage?

Stupid boat.