Vintage SRX pics

Those are some nice sleds pictured! You guys did alot of work to run them and keep them looking like that too!

Yes – It worked very well on the first 74 GPX. You will be astounded with the hole shot.

If you build a suspension dyno – so to speak – you would see that there is no weight on the front half of the skid under pressure. Yamaha built the consumer race sled to try and keep the skis down. Any drag on a Yamaha engine just kills it.

The extended shock arm gives it that needed leverage and simply plants the track. You will also need the rear GP 433 springs NEW. You can add some hockey stick struts to wind up the spring even more. There is one more thing at the rear scissor reversing a part gives about 1” of sag. Don’t worry about that yet. Do the above and you will be shocked it’s the same sled. (If it’s shifting right. 5000 engagement and I think max HP was 8250 RPM.
Click to expand...

I just have my old 75' GP parted out as well as some 76' GP parts and they aren't much.
How does one go about finding those springs new? Or would something else work? The only odd mod I can see is that someone mounted the rear arms to custom made angles that come down off the floorboards (like what my 78 Exciter has for stock mounts).

I'm not building a full blown supermod but these ideas are good! Thanks!
 
Just size the stock GPX springs and find some bigger diameter.

No...the suspension was all stock components and mount - I just assembled the rear wrong one day and it was a miracle. :o|

The only change to the front of the skid, was the longer leverage of the shock spring mount using the GP433 arm. Again - you can easily modify the GPX arm.

We also drilled and drained the stock shocks as the rebound was too slow.

Oh....just remembered....it came with an slot in the chassis where the front bolt mounted. A device was made with a bolt and a big washer to hold the skid bolt. It had a extension on top - a 90 - that the adjustment bolt went thru.

So - you loosened the skid bolt and then turn the adjusting nut to move the front skid up and down. Then re- tighten the skid bolt.

It was pretty well left in the stock position or slightely down.

Also - nice picture of the 340 SRX.
 
RJH
i have seen the front suspension arm adjuster you speak of, Jeff Elliot had one at Haydays in Mpls a couple of years ago. it was Lennard Champouxs' (spelling?) old snopro. yamaha had some great ideas for their snopro racers back then.

beautifull sleds Leon.

attached is a shot of my '75 GPX 433.
 

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My baby.. pretty much as I got it so it's not all beat to death. Snopro, I notice the 74' skis on yours like mine has... Nice sled! Did some of them come with earlier style skis or are they just put on because they are tougher?

vbgarage.php
 
RJH, you seem to have been around this sport for a while.? I have a 78 SSR that has a lot of unusual bits on it. It is number 8HO000117. This SSR has a offset steering post, aluminum handle bars, magnesium bell housing, chaincase and cover. The cylinders are not marked with casting numbers, have liquid cooled exhaust ports and 3 bolt intale flanges. They also look like magnesium. The complete sled weighs about 300#. I am trying to identify all this stuff and also who was racing this machine in the day...
Mark
 
Hello,
Well there's a lot of talk here on rear skid mod's. I'm just about done working on my 77 srx that I'm planning on running on the grass in 440 vintage mod. Any ideas on changing things around? I have one skid that has three extra shafts for six wheels. I got it from Eric last weekend. I plan on using that skid for the grass with a kimpex speedster rubber track and leaving the stock one for the ice with a cleated track. Any help here would be great. Thanks Dean-o
 
I don’t have knowledge of that sled in detail. I’m sure more knowledgeable members can answer. 300#’s seems light for it with the stock track. I have seen them sell for between 10 and 12K on ebay. :o|

We raced a factory SSR for 1 weekend, as above – I thought it was 80’s maybe not.

The factory sled had the steering connection located under the chassis as the engine was lowered to the belly pan. The sled was super light – it was the fastest friggin straight line 440 I have ever or since driven. It had monster factory Mikuni carbs. It was poorly set up for my style – so much potential.

They took it back – but we could have made it so fast. They let me ride a stocker as well and it handled way better with the engine in the stock position. Maybe a ½” higher yet would have railed it.

My knowledge of individual sleds is limited. After 77, we just played on ATV’s building Yamaha’s first suspended ATV and then raced flat track for fun. Then in the 80’s we went on an engine sabbatical until 1999.

In 99/00 Yamaha sponsored us again in snocross (uggg – I hate not winning.) I’m back here to learn and have a request at Yamaha Canada about snocross again.

Hope somebody chimes in with some SSR detail.
 
I Raced A Srx 340 Mod In The Mid 80's And I Had The Info From Yamaha At The Time. They Told Us For Oval Racing Take The Rear Shock Out And I Did And The Sled Reacted Very Good From A Handling Standpoint And Also Gave A Good Holeshot. I Also Have A 77 Srx Without Any Casting Marks And Some Very Different Intake Ports There Is No Bridge. At The Top Of The Intake Port There Is A Teardrop To Retain The Ring Endgap. I Saw Alot Of 8f2, 8a7 And 8ho Cylinders But None Like These
Leon
 
Dean-o

You only need more force "down" on the front rail. Add more springs or increase leverage - or lower the front bolt - and use heavy springs in the back.

very simple.
 
My cylinders are bridged intake. no casting numbers. This sled had the 50mm Mikuni Butterfly carbs, a friend of mine inadvertantly sold them on me... Wish I had them.
I am still trying to figure out who raced thes sled back in the day. Any info out there??
 
I have a spare 50mm kehin sitting on the shelf. Make an offer

- RJH I thought that heaver/stiffer springs in the rear would creat less down force on the front of the skid. My SR lifts and pushes when I'm on the gas, so I raised the tension on the springs and it seemed to help some
 
Is the steering "Y" outside under the belly pan?

If you had those carbs it may have been a been a race sled. I'm dead against boring carbs - but the ones on the sled I drove seem to work.

There was one mod and one stocker for Yamaha Canada West. I'm not sure how many went to the states. Maybe 6?
 
the steering geometry is all stock. except I did try a set of ski wideners? - the ones that spread ski's out 3" and raise front 1". they helped little, then I put the left spreader under the spring, and the right ontop of the spring. helped even more. I have a mid 80's phazer skid underneth. I can still tighten the limiter strap some more, so I will do this over the summer as well
 

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I have the sled on display at a friends business. I can't remember the exact placement on the steering mech. I thought/think it is all above the thin aluminum pottom pan (not really a belly pan, just between the frame area). The down tube goes through a nutch in the motor plate, directly between the 2 rear mounts. What do you mean when you say "Y"? The carbs were with the sled, I bought it from a friend 15 or more years ago. He had lent the carbs to another friend and they never came back... I think the track is an arctic z cleated (based on the 3 drives).
 
"Y" wrong term but where the down tube connects to the tye rods. That point was below the belly pan.

292 - the stock speed boat wasn't made to turn - but ride the banks.

Maybe raise the front skid bolt up 3/4"?

I would think the skis would work better in closer - like stock. You are just getting more weight on the inside ski - sounds like.

I'm sure you can feel the difference - so I may be wrong. Well...the way to get fast is to do more wrong thngs than anybody else. :o|
 
speed boat - thats cold man, LOL! I love my little sr292
yea front skid height will be the biggest factor for me this year
why do you think the narrow ski stance would be best?
monty
 
sr292 looks good

Hi Monty......maybe toss the hydraulic unit in for a try ,,,just kidding
Looking forward to seeing you in July ......All these polished SRX make
my sleds look plain ,,,,I guess i,m tooo old for such sleds (and fragile)
I'll stay with my smooooth drive sleds ....
Will connect later ......RON
 
292

There were affectionately called speed boats.

I raced a speedboat 433 and 600 (whatever it was 643?) 292 one time. We won on a banked oval with the 292, but it was too hard to win on it and no real fast twin Polaris’s were at that race.

When we raced on flat tracks with that chassis – we put in 20 million picks. All that did was make it like a bed of nails those guys lie on. That made the back easier to follow the front. Never won on a flat track with that sled.

You need to get the weight – on that outside carbide. If you do the math thing – you will find – even in the stock position the moment of pressure is well under and inside the ski. A GP chassis would smoke that sled in the turns. :whine:

I have a vintage picture of our GPX inside ski steering somwhere - Ill try and post that.

So therefore – you turn with the inside ski on that sled – and that’s why you have to lean as you are putting more of your weight…on the inside ski.

I hate to brag (well not really) if you look at the picture – to the left – notice how the sled is so nicely balanced. That was in the 90 mph range and shear ice. The sled is hooked up on the outside ski – not the same bite as an independent – but the inside ski is just feathering the ice. The clutch setup helps steering a lot as well. :dunno:
 
yes, I understand that I need to transfer weight to the right ski. Thought I was on the right track with the ski spreaders on top of the right spring and under the left.
Back in my cart days, I could twist the chassis to transfer the weight better. I mounted my lube tank under the right foot board to help keep the weight on the right side also. Just need alot more track time to keep playing around.
I've heard you call my SR a speed boat over on the vintage sleds site!!!! so I knew you were just giving me a hard time LOL!
I also just recieved a FREEBE SR433 motor! its stuck and looks like it was laying in a sand box for the last 20 years. Hope I can salvage the cylinders!
 
I believe all of the steering is above the bottom pan. There is a bell crank and tie rod assembly just ti the right of the steering post which rotates a shaft that runs front to rear inthe center of the sled (just under the recoil), this has a stem at the front that the steering tie rods are on.
 
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