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Author Topic: 1975 Yamaha GPX 338  (Read 7595 times)

Finch

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1975 Yamaha GPX 338
« on: December 30, 2014, 04:24:33 pm »
My dad was showing his 1972 Skiroule RTX race sled at a local event trying to drum up some interest in the Vintage Snow club and a guy comes up, says "nice sled" and that if my dad wanted he had "3 Yamaha GPX" sleds in his garage storage and if he wanted them come get them. We loaded up a couple weeks later and got the sleds, so for $20 gas this was the haul

URL=http://s452.photobucket.com/user/gigaterraalpha/media/Mobile%20Uploads/20140830_124456.jpg.html][/URL]

Got a 1975 engine, '74 engine, tons of bits and pieces, enough to get a decent runner out of the group of parts basically. There were 3 sleds at one time 2x1975 and 1 '74 which he didn't have the chassis for in the garage. Either way, for free I wasn't complaining.

Considering the rough nature of the bodies I'm going to make a decent fun running sled out of my pile of parts that I can take on some vintage rides with my dad and so I'm not just working on "his" sleds :P, but I've come to grips all I'll have is a rider because there are no show parts in this pile!

I took the chassis and hood from the sled in the photos with the skis on it, I've cleaned it up and out. The 1" of grease/dirt/leaf mixture scraped out of the pan very well, still took a few hours and a can or two of elbow grease.

This is just the start, I've progressed well on the project so I've got some photos to post and I'll get them up here asap!! PRAY FOR SNOW!! (or that the engine guy actually works on my engine I dropped off in September??)

Vintagesleds.com

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    Finch

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    Re: 1975 Yamaha GPX 338
    « Reply #1 on: December 30, 2014, 08:01:26 pm »
    Ok. Got a few more photos uploaded of the project.


    Here is the chassis I chose between the 2 I got out of the deal. Pretty dirty, and it was run. The seat was something else too, one of those "any bar in a snowstorm" kinda seats, as seen from the whacked out rear bumper and 1x3 strapping. Both steering shafts were snapped and rewelded, poorly at that.



    Here is the pan and the nice black goop that oil, dirt, and leaves turn into :P



    And the inevitable mouse nest that was under the seat. Luckily, one of the 2 seat foams could be used again. I'll post a photo in the next round of my recovering job with the damaged foam and the adventures I had rebuilding the seat and everything that went with it.

    Finch

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    Re: 1975 Yamaha GPX 338
    « Reply #2 on: December 30, 2014, 08:21:01 pm »
    Ok, probably todays last post and photo upload.


    This is about 1/3rd of my way into cleaning and doing my very best at straightening out pretty much everything to do with metal, because I'm just about certain that everything was bent. Finally I'm happy my brother chose to become a journeyman welder, because MAN do I have a project for him. The pan has quite a few dents but I've been pretty successful at knocking them out and getting things fairly straight. It's all in the usual spots from what I understand, center of the pan under the steering, the odd knock here, tears by the hood hinges (from picking the machine up from the front of the bumper, duhhh) but totally useful part for my needs because it's going to be run it'll dent again I'm sure. I'm an electrician so that's why a cover plate was my scraper of choice :)

    Here's another of the belly pretty much ready to head over to my brothers place for a bit of welding which hasn't happened yet, maybe this weekend. Wouldn't mind him fixing the nutty steering shaft too. He's going to fill all the "extra" speed holes that the chassis gathered over the years of Frankensledding.



    Yes. I cut the bumper off. The last bit on each side had taken a hit right by where you feet sit on the rests, denting in the sides and breaking the cast aluminum "bullet" holders at the end. I'll find some eventually, just like I'm sure I'll find a serviceable bumper too but for now this one had to be cut to make it not look terrible, but it's far from finished product, just a step towards the end product. I still would like to find a new set of front hinges, these had been drilled and wired, but oddly enough the hood clips on the side are perfect. You can see some of the cracks in the pan, but my bro will make those vanish. I'm also going to get him to make something to support the front bumper and the pan when lifting, really terrible design to have zero support where 99% of people will be attempting to pick the sled up.

    Finch

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    Re: 1975 Yamaha GPX 338
    « Reply #3 on: December 30, 2014, 08:54:12 pm »
    Just threw the hood on the pan, after recovering my seat. I've foregone polishing the tunnel to a shine in lieu of a more "matte" look that I've gotten with 4 ought steel wool, polish and a lot of handwork. I only did it to mock it up, as my engine hasn't been touched yet by the builder looking after it, so I can push myself towards continuing the project.


    The seat covering experiment was fun and educational. The seat will only look as good as the foam underneath, lucky for me, my foam was about 85% with a couple burns in the centre so the seat as a dip or two but hardly visible. The real flaw you see is because it had been shipped with a new rear aluminum tunnel piece courtesy of Koch, but it must have put pressure in the material during shipping because you can see a line in the cover where they were in contact with one another.


    Here is the rear tunnel piece riveted on, the one that left the marks in the seat cover :(


    Better view of the "line", and my wife and baby. I'm a lucky man that I can recover a snowmobile seat on the kitchen island.


    Thanks for following along guys, I'll keep it coming. I'm having lots of fun learning and I haven't even started this machine up yet! Plans are to throw on a pair of Mikunis take a trip to Royal Distributing, get the engine back from the builder, and have a fun marathon weekend putting it all together and tuning it up. Still gotta over haul the skid, get the skis welded up a bit and throw some paint on everything but it's going to happen!

    IowaSledKid

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    Re: 1975 Yamaha GPX 338
    « Reply #4 on: January 21, 2015, 04:55:24 pm »
    Seat cover looks good. Just looks like it wasnt pulled tight enough.
    ss yamaha exciter 440 #17G
    super mod yamaha sr 440
    Yamaha's-3 8E8,889,8JO,8U3

    MACK

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    Re: 1975 Yamaha GPX 338
    « Reply #5 on: January 22, 2015, 02:33:21 pm »
    I'm crying in my morning coffee!!!

    I don't need to see, hear, read this sort of story!!! LMAO!!!

    Some guys have all the LUCK!!!

    I'm drooling over this score.

    I want....oh so VERY BADLY.....to have a '75 GPX 433G like my dad had back in the day. But I would certainly have been VERY happy with this 338G score!!!


    HOLE-EEEEEEEEEEEE CRAP!!!!


    I bow down to thee for being in the right place, at the right time, to have such a GENEROUS individual walk up and offer ALL OF THAT...for.....for..........for..... FREEEEEEEEE?!??!!!  :o :o :o :o

    You gotta be KIDDIN' ME?!??!!

    You da man!!! CONGRATS to you!

    Thank you for taking those sleds and those parts and restoring them and putting life back into them vs them getting hauled off to a scrap yard to be crushed...never to be heard from nor seen again.

    Thank you thank you thank you!!!

    Green with envy here.....

    :thumbsup:

    - 1978 Yamaha Exciter 440

    - 1978 Yamaha Exciter 440

    whereswade

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    Re: 1975 Yamaha GPX 338
    « Reply #6 on: January 25, 2015, 09:37:52 pm »
    Always good to see someone learn how to do stuff and save something in the process. That is what I'm doing with my GP and SL 338. I don't kiw what I'm doing, but I've gotten them running and I took my brother and my youngest two kids to Waconia yesterday, and even thought they are strictly runners, nowhere near how nice yours are, they really are fun!

    Enjoy!
    1983 Yamaha SRV
    1986 Yamaha XLV
    1992 Arctic Cat Lynx (parts)
    1992 Arctic Cat Prowler
    1994 Yamaha VMax 600
    19?? Polaris ?? Chassis (parts)

    Just getting the hang of this vintage thing…but it's certainly got the hang of me!

    AllSkiDoo

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    Re: 1975 Yamaha GPX 338
    « Reply #7 on: February 18, 2015, 11:55:41 pm »
    Super job on this sled.  There is lots to learn.  Ask these guys on here, they have answers to your questions when they come up.  I only get to use the dining room table when my wife is at work.  ;)
    1971 Ski Doo TNT 440
    1972 Ski Doo TNT 340 Special
    1972 Ski Doo TNT 440 (for parts)
    1973 Ski Doo TNT 294 Silverbullet
    1973 Ski Doo TNT 400 F/A

    Finch

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    Re: 1975 Yamaha GPX 338
    « Reply #8 on: August 27, 2015, 11:41:32 am »
    It's been awhile! I have been at it, but slowly. Picked up a pair of pistons and got them to the engine doctor, should pick the motor up this weekend, that should spur me into action. Photos of the rebuilt 338 soon fellas!

    Finch

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    Re: 1975 Yamaha GPX 338
    « Reply #9 on: September 06, 2015, 12:33:17 pm »



    It's BACK! Got the engine back from the builder and it looks very little like the one I dropped off a year ago. Bored first over now, and every last gasket, seal, and bearing have been changed out, all Yamaha parts too! Work was done by a local Yami specialist who drag raced them years ago, and let me dip into his old parts supply! Timing was out, lots was wrong, lets just leave it at that. Still have to source a couple 32mm Mikunis and get it running but don't feel that will be an issue.


    MACK

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    Re: 1975 Yamaha GPX 338
    « Reply #10 on: June 09, 2021, 08:35:45 pm »
    If anyone happens to have a very clean, complete and original....OR....a beautifully restored 1975 Yamaha GPX 433G that they'd be interested in selling, I'm interested to see what it is that you have and wanting to speak with you. First send pix and details via PM here on this site, or email to:  [email protected]   Then we'll go from there.

    Not interested in any 338G sleds

    Not interested in any '74 338F nor any 433F sleds.

    Thanks
    Ryan Mack
    Indianapolis, IN
    - 1978 Yamaha Exciter 440

    - 1978 Yamaha Exciter 440