75 SRX snopro????

I wonder who's sled it actually was? Wayne Trapp's 338 is in Crivitz wi,owned by Jason Remiker,i've seen that sled and he posts on here on here sometimes.
the other Trapp sleds are in Washington the last i heard.In the past i I've seen a classified Listing Larry Omans 440 liquid for sale,so he must of had a 338 too....maybe his?.I guess i never thought about the Canadien racer's having them.the guy i bought my cylinders from had a few sets for sale.
Didn't these sleds also have the internal rotor ignition? aluminum suspensions?
Lynn Trapp's 440 was the first one built and supposedly the most original of all of them left.It was at Waconia a while back
 
About the only similarity between the original 75 race sled and a GPX – was that the bolt holes were the same.

The chassis was mostly all 7074 T4 aluminum as was the entire skid. If anybody has mine…..the difference in the one we raced was the jack shaft was steel but the entire mid section was turned down to about ½”. We could turn the steel down smaller than the aluminum. Every bolt was small or machined small as well. My sponsorship was to race in Canada only.

It had a specific track – nobody else had. It was a gates belt – on backwards with arboly bars (coated titanium). The bars were braced up against the rubber to add support.

We had the cat clutches as well.

They all had TZ rotors.

The 1976 pro sleds had the ski extensions – the 75’s did not. There was very little difference in the chassis – but I liked the water-cooled GYT motor better the factory GYT’ed 76 SRX. Ours was faster.

I have only seen 76 race sleds in this post, even thou the engine shown is a 75 - 340 or 440 with 75 pipes. Omans sleds would have ended up back on the west coast. Oman’s 74 were sold to a dude in Quebec. At the time, we smoked them with our heavy mod stock GPX’s – so the dude put them back in his truck and I never saw them again.
 
RJ,whats the difference between the 75 watercooled gyt cylinders and the 76's with the race kit? I've only seen pics of 76 cylinders and haven't compared them side by side.i do know my cylinders have the shortest intake tract i've ever seen.Also could anyone buy the race kit for the 76 srx 340? what did it consist of? pipes,cylinders injectors and heads? I've seen pics of a 72 thunderjet 340 with the the srx 340 that had the one piece head.{gyt head?] that was raced in eagle river in 1976.i guess you could bulid you racer in those days when factories pulled support,this one was raced in super mod 2!
 
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1975 Yamaha GPX
One of Wayne Trapp’s original 1975 Yamaha GPX PDC racers has been restored by Jason Remiker of Mishicot, Wis. Like many former race sleds, this Yamaha led a tortured life after is was retired from factory team service, and was once even fitted with a battery-powered head light for trail use. It remained surprisingly intact, however, and is shown here with its original hood and pan restored to near-new condition. The seat has been reproduced, according to Remiker, because the original was cut on the front to make room for a trail-sled fuel tank. The original welded aluminum racing tank was also reproduced. The sled still has its original Yamaha fuel injection.
 

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Monty – by pancake…do you mean the speed boats like you have? They have enough HP – the 650 needs 3 head gaskets – if I owned one – I’d move the engine about 5 inches to the right – looking forward. Like we mentioned in the vintage forum…the only time we won on them was on banked ovals!

TJ440
I’m not sure what they could buy for the 76. I thought it was pipes and M’s and specs? The factory sleds had stock modified barrels – trick pipes you could not get and everything thing was aluminum. The 75 GYT factory engine was almost if not identical to the GYT free air cylinders. We chose the 75 engine over the 76 as the 75 had more engineering input. The pipes made the real HP.

We ran the engine as it came on AV gas at 40:1 Bardall (sponsor) and when the big guns came to Canada, our sleds smoked everyone. (My sponsorship was Canada only) Rotary valves – reed valves – everyone!

Please don’t forget – it was an 8 day a week job for us and with that time, we probably had more HP to the track than anybody.

Just like the Nascar truck series. They told the Asian entries – you build this engine – like this and don’t try and cheat. So why were they so much faster out of the box, in the beginning, – with an engine they had never built before …… because they got 30 more HP to the wheels than anybody else. This point was just brought to my attention last week from my old race mechanic. They dynoed the cars at the wheel – for proof.

Monty
That’s the baby – set up right –nothing would beat that thing in vintage –if he had some real carbs on it.

The picture is our 75 GPX mod stock in action.
 

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Bob
I refered to the "pancake SRX" as in the original post I put up on the first page. Lynn Trapps 440 srx.
My little SR is actually a 643 that I run a little 292 in. Good power, but I have alot to learn regarding setup. Steering is better this year as last year I could not get it to turn worth crap. Setup, Setup, Setup.... I'll eventually get it right.
My GPX I want to put on the grass for something to do this summer. I have both a '74 gpx338 and a '75 gpx433 motor. Dont know which way to go yet. I do have the GYT specs and will atleat bring the motor to thoes specs. Trying to find a set of GYT pipes for it now.
Do you know anyone that could help me with motor work?
 
Monty,from what i have heard Bob Jahna in Ohio is the guy for the sx engines.
if it's just something to mess with,have a crack at yourself.I just did a simple port clean up, matched the sleeve,recessed the combustion chamber,and added mikuni carbs to my 433.Carbs aren't 100 percent dialed in yet,our weather has gone from -30 to 15 above in the last week or so but after breaking it in gently i was actually surprised how hard it pull's.
 
Ive played around with my own stuff, but some things I am just not comfortable with. I would hate to mess up a set of GPX cylinders playing around. Last summer I bought a bridgeport and have been working with some "stuff". But I feel more comfortable messing up a set of enticer cylinders than the gpx.
 
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