1990 Yamaha Superjet Retro Race Ski Build
pxctoday

» Log in

User Name:

Password:

Not a member yet?
Register Now!

» Find OEM Parts

» Jobs

» wallpapers

Page 1 of 2 12 LastLast
Results 1 to 10 of 17
  1. #1
    PWCToday Newbie samcapt's Avatar
    Join Date
    Sep 2017
    Location
    California
    Age
    22
    Posts
    16

    1990 Yamaha Superjet Retro Race Ski Build

    Back story on this build. A coworker of my moms used to race skis back in the day for Bellflower Motorsports in California. He gave me a cylinder and it all snowballed from there. I had the cylinder before the ski. The ski itself is a 90 model with a stock 650 and a coffmans pipe, ac pole, skat impeller, pro tec open grate and ride plate. nothing special but was clean and local to me. I purchased it from the original owner, an older gentleman from Laguna Beach were it was purchased from Mission Motorsports new. (this build has mostly been completed and has been ridden a handful of times this summer and there are a few parts that are in the process of being added and changed)
    41376738_2011419135585742_2662214175387811840_n.jpg

  2. #2
    PWCToday Newbie samcapt's Avatar
    Join Date
    Sep 2017
    Location
    California
    Age
    22
    Posts
    16

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    The ski sat for a while till I got a 62t motor to start with. The motor I started with was a mess but solid. The only things from that motor I used in the end was the cases and starter bendix. The stator that was in the 62t motor was damaged so I used the stator and flywheel out of the 650 motor that was in the ski along with the 650 e-box that the first owner had put an msd enhancer in. For the carbs I found a 98 GP760 a few miles from where I live for dirt dirt cheap so I picked that up and used the manifold and 44s for my motor, because I knew 38s weren't gonna be enough and the 44s would provide the airflow needed and were really clean. The 38s not so much. The cases were ported and matched to each other and to the cylinder.
    41392525_2011404278920561_3067333499544403968_n.jpg
    41507769_2011404318920557_6043714186058399744_n.jpg
    Last edited by samcapt; 09-10-2018 at 06:55 PM.

  3. #3
    PWCToday Newbie samcapt's Avatar
    Join Date
    Sep 2017
    Location
    California
    Age
    22
    Posts
    16

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    The cylinder was the big thing for this motor and provided the most trouble. This is not an oem cylinder, its a PRO TEC cylinder that the company made before they were outlawed from my understanding. Each exhaust port has two extra boost ports on each side. Ive been told there were only around 20 or so produced and the only other one I know of is some where back east. The trouble with this cylinder was you have to run the PRO TEC cast rec o-ring head with it. Thats what the cylinder was designed with and for. With the cylinder being so thick and head also there is no need for a girdled kit and no way to run one. Finding the head was quite troublesome, searching, calling, emailing for months trying to locate one. Finally I found one a gentleman had in his garage in a box. Lucky enough also he was in San Diego which made it much easier to acquire the head. And since I had it, the build could commence once again.
    41374827_2011404762253846_5389167762922799104_n.jpg41328262_2011404345587221_1958642049188102144_n.jpg41354589_2011404385587217_5088265399296851968_n.jpg41412396_2011404415587214_2713393478133350400_n.jpg
    Last edited by samcapt; 09-10-2018 at 07:10 PM.

  4. #4
    PWCToday Newbie samcapt's Avatar
    Join Date
    Sep 2017
    Location
    California
    Age
    22
    Posts
    16

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    The motor was assembled in my garage with the help of my father. New AMI crank(stoke stroke), OEM Yamaha pistons(stock bore). All said and done the motor came out with 150psi in each cylinder. Nothing special but practical. Ive contacted PRO TEC and they said they can cut the head and up my compression which ill do later. But for now the ski rips and is perfectly fine. I also meet a guy who had a set of brand new ocean pro flame arrestors in his garage which are on the ski now and go together with retro theme.
    41392503_2011404458920543_4548464593751506944_n.jpg41535047_2011404478920541_5069551591133020160_n.jpg41391910_2011404535587202_994383133451223040_n.jpg41410699_2011404632253859_3333487279938207744_n.jpg41471193_2011404662253856_2128327827571867648_n.jpg
    Last edited by samcapt; 09-10-2018 at 07:28 PM.

  5. #5
    Top Dog RIDEH2O's Avatar
    Join Date
    Jun 2011
    Location
    nevada
    Posts
    1,890

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    Nice!
    2017 Jet Jam Racing "Region 2" Sport GP Champion

    Thanks 2017 sponsors....
    Lets do it again in 2018

    Reno KTM
    DirtTricks
    Reno / Tahoe Watercraft Connection
    Hunt & Sons / VP Racing Fuels
    Garate Enterprises (The Powder Man)
    On the Mark Construction, Reno NV

  6. #6
    PWCToday Guru Steve C's Avatar
    Join Date
    Oct 2002
    Location
    Franksville, Wisconsin
    Age
    57
    Posts
    421

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    Looks good. Them are nice cylinders, not many around

  7. #7
    PWCToday Newbie samcapt's Avatar
    Join Date
    Sep 2017
    Location
    California
    Age
    22
    Posts
    16

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    Ive always liked the look of the RRP handle poles and want to put one on the ski. I knew it could be done and have seen it but wasn't to sure on how others have done them. I looked all over to find was to do the swap and came across a conversion bracket. It’s made by watcon/ rock county jet ski and it’s a direct bolt on. The bracket allows you to run the aftermarket poles with making the uprights one inch narrower than the stock bracket and slightly tallallowing you to run your original pole bolt with providing spacers that take up the excess space on the out side of the up rights. The other thing that is needed is a round nose pole spring.
    F1E9EA47-EE22-442F-B3CB-58576612504B.jpeg 1CC449D2-AD62-465C-8A0A-099F362E3B03.jpeg 9F1D6111-6513-4D3C-98B6-0C98C244C599.jpegA947F0BF-1304-4171-8968-D4C040F6C148.jpeg B717F241-D6BF-479B-AC77-C63EDCEED444.jpeg 5B6F92E5-7F40-4E19-B93F-37081E72F3AB.jpeg0D3B769C-CF80-47D8-B525-90D08C442455.jpeg
    Last edited by samcapt; 09-12-2018 at 12:41 PM.

  8. #8
    PWCToday.com Is My Home Away From Home
    Join Date
    Feb 2013
    Location
    NorCal
    Posts
    2,022
    Blog Entries
    1

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    Nice build man! Any head will work on those cylinders Thrustinnovations.com makes a nice non-girlded head with exchangeable domes as well.

    What are you going to run for an exhaust and pump/impeller?
    triceps are the biceps of the back of your arm.

  9. #9
    PWCToday Newbie samcapt's Avatar
    Join Date
    Sep 2017
    Location
    California
    Age
    22
    Posts
    16

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    Thanks. From my understanding from talking to pro tec they said the cylinder will only work properly with the head I found and am using. I’m not doubting there’s another option out there but right now I’m happy the way it runs.

    Right now just the coffmans exhaust that came with the ski originally but ported the manifold to match the exhaust ports and smoothed everything out. Next will be a mod b-pipe.

    Up till about 2 weeks ago I was running a stock pump and a skat impeller that was in the ski when I got it. It worked quite well like that, but could tell it was holding it back and there was more to give. So I got a solas 12v mag pump and a new skat impeller with the proper pitch for the ski and how it’s set up. I ran it over Labor Day weekend and those two pieces made a huge difference.

  10. #10
    PWCToday Newbie samcapt's Avatar
    Join Date
    Sep 2017
    Location
    California
    Age
    22
    Posts
    16

    Re: 1990 Yamaha Superjet Retro Race Ski Build

    The pump and impeller were the next things on the list to be changed. It came with a stock pump and a skat impeller that worked well but still had more to give. So I got a 12v solas mag pump and the right pitch skat impeller for the application of the ski. Those two made a world of difference in the handling and preformance department. Highly recommended.
    0176D34E-A460-4990-8DF6-8B99108E1942.jpeg780E5287-2637-446A-AE47-7C7AA337277F.jpeg
    B5CDE1B2-69D2-422A-AC7F-3DA158F587E7.jpeg4142480F-5A67-4D81-9D1E-A065058E85B6.jpegE27CC176-A076-4216-B1C4-2DFC74F65E0C.jpeg
    Last edited by samcapt; 09-12-2018 at 05:26 PM.

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBadvanced CMPS v4.2.0