1973 SR 643B Eagle River Build

2ooosrx

2ooosrx

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Joined
Oct 2, 2004
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Age
34
Location
Gurnee, Illinois
Website
www.cbperformanceparts.com
Hey guys,

Over the last 4-5 years we have become fairly involved in vintage ice oval racing and decided to finally grab our 1973 SR 643B down to restore it and potentially race it at eagle river in 2012. The sled has not been run since the early 1980's but used to run many grass drags back in the day and did very well. I believe it ran 108 mph in 800 ft when it used to be dragged and put out 138 HP on an engine dyno many decades ago. The sled is run in a 292 chassis and it used to be Ed Schubitzke's sled. It ran ed's custom pipes and fairly excessive porting along with 52mm fuel accelerated carb's. We also have Jim Adema's stock motor at our disposal that he used to run in his 643 Thunder-jet.

Our goal for this sled is to get it cleaned up and performing extremely well so it can potentially be raced in the world championships for next year. Here are some pictures taken of the sled after pulling it out of storage and dropping it on the table. There is a lot of work ahead of us but this sled deserves to be out on the track running again. If you feel you have any parts or information on this animal, we are all ears. Thanks







 
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Your Killing me. I want a 73 SR433 or 643 Bad. Looks like a great sled,can't wait to see it done. If you find another one you don't need Please pass it on to me.

Mark
 
Yea, these sleds are extremely rare to come across. They get top dollar too when they are sold. I have read that only 150 of each engine size were made. Good luck on your search and hopefully the sled turns out pretty well.
 
very good start. and that'll buff right out ;) my father has a 72 thunderjet 650, same engine right? he is the second owner, bout it like 35 years ago I think. lost a piston and has sat inside the heated garage for a long time. makes me want to get his running again! nice project man. and knowing your work, it will be AMAZING when its all done!
 
Man I love the Yamaha SR Sleds if you have any questions just ask. man that was a clean sled when you got it . Here is a picture of are SR Sleds
Thnaks Joey

DSC00159.jpg
 
those are some fantastic looking old Yamahas you have there! thanks for sharing, and welcome aboard!!
 
Does that 292 have YZ-702 stamped any were on the chassis the reason i asked is because that was the # that indacated that it was a factory team Yamaha race sled. also i have a SR registry i took over and was wondering if you would be intrested in, if you are call me 715 432 1534 Thanks Joey
 
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Here she is all stripped and ready to be polished and reassembled. We may end up extending the ski stance but are a bit hesitant at the moment. The spindles and all loose ends will be re-bushed for a solid frame. The crank is being trued at the moment and a new displacement size is also being determined.

 
there is SOOO much there for you guys to do your shiny magic to :) cant wait to see things progress!!
 
Yes, literally the entire chassis is aluminum. I will be curious to put this on our scale when the project is complete to see what she weighs. Numbers aren't official yet, but we are hoping to be able to punch the cylinders out to a 78.5mm bore putting that sled at 677cc.
 
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yeah, I think my dads 76 340 srx is the same way. not positive though, been a while since I looked at it
 
Yes the 76-77 srxs are almost all aluminum too. We actually won the 340 liquid super stock class at eagle river this year after throwing a 76 340 SRX together with very little testing. We are extremely pleased
 
Funny I also have a 73 SR643B and it is on a 856 frame and the number is 000102 witch makes it the second one made. If you need a mag.head I have one to trade for a good uncut pto side if it could help.
 
2ooosrx said:
Yes the 76-77 srxs are almost all aluminum too. We actually won the 340 liquid super stock class at eagle river this year after throwing a 76 340 SRX together with very little testing. We are extremely pleased
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wow someone else has a 340 srx as well :) not a ton of them made, pretty neat. I guess he is considering selling. I hope he doesnt, I like it and want to give it a try at the local radar run. what are you running for carbs? his has the gyt fuel injection. circle M I think it is called?
 
RICKYAMAHA said:
Funny I also have a 73 SR643B and it is on a 856 frame and the number is 000102 witch makes it the second one made. If you need a mag.head I have one to trade for a good uncut pto side if it could help.
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Thanks for the offer, when we figure out more about the motor I will let you know.

As far as the 340 SRX, we are running 38mm round slide carbs. The fuel injection is in fact called Circle M.
 
yeah, thought so. I THINK it has all the "gyt-kit" as I have heard it called. really not sure though, I just hope he doesnt sell it and I get a chance at it on the ice :)
 
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