Surfjet!

[delagem]

Well, I picked this up since I abandoned the ill-fated Canoe-ski project.

It's a 1984 Surfjet 236ss Freestyle. 255cc Fuji twin, vertically mounted.

Anybody familiar with these things? Any performance tricks? I understand that they only go about 25mph in good condition, I'd like to speed that up a bit....

[Live2ride Powersports]

Re: Surfjet!

I had one i bought for 50 bucks, but would be surprized if it did 15mph. It wasn't in great shape, but ran ok. Resold it for $250 a couple years ago.

You will have fun with it, alot of attention from people to. LOL

[john zigler]

Re: Surfjet!

those were made right here in janesville!

cool old school stuff.

[gto0209]

Re: Surfjet!

does it have a pump or prop?

[Live2ride Powersports]

Re: Surfjet!

does it have a pump or prop?

Pump style

[delagem]

Re: Surfjet!

The board was about 30 lbs overweight. Should weigh 130lbs and mine weighed 162....

Let the refoaming begin!

[Minnetonka4me]

Re: Surfjet!

Theres some guy up here that has 4 of them...and thinks he's gonna get $2500. LOLOL

[delagem]

Re: Surfjet!

I guess I need to start a build thread, but for now, here's a few photos of what I did.

The combustion chamber design is a total disaster. The angle of the squish band is backwards! We wound up using a comparator to determine the angle of the piston, at 7 degrees, made a jig to spin the head on a lathe, and then milled that angle into the head.

Then, rechecking the squish showed a 2.7 mm gap. So we milled the block a full 1.8mm, to close the gap up to the recommended 0.9mm squish for this diameter piston (.9 pulled from Bell's book)

Cutting the head increased head volume from 9.0 to 9.6cc. Skimming the block by 1.8mm countered this, and then some. The stock SurfJet has a compression ratio of 11.0:1 , the modified head calculated out at 11.8:1. I also checked it old-school style, where I put the piston at TDC, replaced the top ring with an o-ring, and also smeared some grease between the piston and cylinder, and then used a burette to fill the combustion chamber with kerosene. Doing it this way is most accurate, and I came up with 12.0:1, right in the middle of Premium 91 territory.

The carb from a 1988 EZGO golf cart fit the intake manifold with a few modifications, and is 2mm larger than the stock BV22. The EZGO uses a BV24.

Refoaming dropped nearly 30 lbs from the weight of the board, the stock foam was very waterlogged.

Trying to find replacement reeds led me to the Boyesen model 423 for the Suzuki DT15 outboard motor, or custom ones made by TDR Racing out of Punta Gorda, FL. Tony at TDR is awesome, his reeds look perfect and cost $20 a set. The Boyesens are $80.

[MCrider]

Re: Surfjet!

that this looks pimp! great job

[Minnetonka4me]

Re: Surfjet!

Dude you are the freakin restore MASTER!! Holy crap that thing has 10 time the R&D time that the manufacturer did!

[1976js400]

Re: Surfjet!

Great restoration --absolutely top notch, I hope to choose a much simpler path and start w/ weight check. There's a good chance it's fully dry since not used for a year or so. If the weight checks out and carb didn't seize, I will apply some addititional clear coats for added water protection then go from there.


Good info, a guy locally wanted a fortune for a slowmoish 60's jetboard in horrible shape exposed to weather.
I was interested in a jetboard until realized it was an early wavejet type setup, strictly assisted paddling out for surfing waves. I was able to print an online manual for this early board w/ weight specs. The guy was nuts and thought it was worth a fortune for 5 to 10 MPH speed max! The thing was a total tear apart restore to make functional. The old foam was rotten and waterlogged--I could tell instantly since piece was too heavy to handle. There was some odd ball unemployed person dealing as the rep for this person claiming he could easily replace damaged foam. I was comtemplating restore on this but guy was really annoying on insisting on foam repair work he could do. I would of given him only a third of his asking price since item was rare anyways but in horrible shape.

The surfjet I got on a deal, has updated graphics. Supposedly water ready --couldn't pass up chance on this ---are these somewhat rare? 25 MPH seems fairly fast standing up w/ NO handlebars to hang on to. The prices for these things are all over the place??? That is such a clean and professional design, easily one of the world's best surfjets. Some restaurants display inoperative jetboards, if that board is ever retired, it should displayed somewhere.