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Post by admin on May 29, 2011 9:57:31 GMT -5
I thought I would start out with a goal to make a Scorpion Snowmobile "Bubble Nose" FAQ. If you see anything incorrect, let me know by posting to this thread, and PLEASE - Post your knowledge on this thread so we can learn from it.  |
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Post by admin on May 29, 2011 10:00:18 GMT -5
1967 - 1969 Sleds have RED handle grips [UPDATE] We've had reports of several 1970 and 1971 models with red hand grips since my original post. Details are later in this thread and here, www.scorpionsleds.proboards.com/index.cgi?board=general&action=display&thread=1701970 is the first year with the hinged hood, and also the brake lever is now forward of the handlebar instead of the previous mounting location which was at the rear of the handlebar like the throttle position! |
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Post by stingerIII on Dec 18, 2011 21:52:12 GMT -5
1971 the last year of the bubble hood Scorpion replacing the side emblems with Decals similar to the Stinger models .With 4 models listed in the advertising brochure (Bubble hoods)with the Mark I and II and the
(Wedge hoods)Mark II Stinger and Mark III Stinger. Other model were available but these were the models
in the advertising brochures.
With Mark I's mostly sporting the old side emblems.
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scorpmyride
L1 Scorpion - The Great Snowmobile
Posts: 3
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Post by scorpmyride on Dec 19, 2011 11:10:25 GMT -5
my 71 mk II has red grips also. there was an early and late model as well. early ones had the gas tank built into the tunnel and the late ones had a plastic tank.
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Post by admin on Dec 31, 2011 13:52:41 GMT -5
Early model Scorpion drive belt.
Found a post from "relic-rider" on vintagesnowmobile.com. He writes,
All of the early Scorps used the same belt. OEM# 789900. This crosses to a Dayco #GTS 717. The belt is 43" in circumference x 1 3/16" width. These belts can still be found easily.
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Post by ddub on Dec 31, 2011 18:27:59 GMT -5
there was an early and late model as well. early ones had the gas tank built into the tunnel and the late ones had a plastic tank. Scorpmyride, I am not sure this is correct. Where did you get that info? What I have found with the wedge chassis anyway is it depends on the engine. Sachs twins the tank was in the chassis. SuperStingers were in the chassis. From what I can see this was due to the exhaust. CCW sleds had the plastic tank. It would be good to verify. The more I learn, the more I realize I don't know! |
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Post by admin on Dec 31, 2011 20:35:38 GMT -5
there was an early and late model as well. early ones had the gas tank built into the tunnel and the late ones had a plastic tank. Scorpmyride, I am not sure this is correct. Where did you get that info? What I have found with the wedge chassis anyway is it depends on the engine. Sachs twins the tank was in the chassis. SuperStingers were in the chassis. From what I can see this was due to the exhaust. CCW sleds had the plastic tank. It would be good to verify. The more I learn, the more I realize I don't know! ddub, Your thought of the exhaust and engine type being the determining factors of plastic tank or old style internal chassis tank makes sense. Here's a 1971 wedge with the internal tank for reference,  Source, www.vintagesledders.com/forums/index.php?topic=8933.msg79716#msg79716I've seen other photos somewhere that showed something like a dual piped wedge 1971 or 72' with the pipes taking up a lot of underhood space going all the way forward to the front bumper, and that sled was also a metal internal chassis tank. So...maybe if the exhaust exits at the front of the sled, it got a metal integral chassis tank, if the exhaust exits at the side of sled, the plastic tank? I don't know.  Although...it would also make sense if they used leftoever 1970 bubblenose chassis with the integral chassis tank in the early run of stinger wedge hood production models in 1971 ! |
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Post by ddub on Dec 31, 2011 21:23:49 GMT -5
Here is a little more info from a thread I posted when the 72 Stinger followed me home. The internal tank had me a little confused as I thought the Super Stingers only had them. vintagesleds.com/bs/index.php/topic,58751.0.html I would agree, EXCEPT, I have a 72 Wedge chassis with the chassis tank! That is what I am leaning towards, which is why I asked Scorpmyride where his info came from. |
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Post by stingerIII on Jan 3, 2012 19:53:08 GMT -5
Admin that wedge you have pictured is a
Superstinger chassis. the exhaust hangers and the wider
front with extra welds looks like a 15 inch track Superstinger.
The Stinger III that I have with the 440 Sachs has the internal
tank and an exhaust that exits at the front of the sled if that helps any.
I have three sleds with internal tanks 71Stinger III 440,69 Mark I,
Superstinger 15 inch track 440 ccw.
I have never seen a Bubble hood with a plastic tank but anything is possible
since back in the day most manufactures would change production in relation to available parts and some to customer requests.
ddub and Admin are onto something here when they say the tanks are matched to the engines and exhausts.
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Post by scorpionlilwhip on Jan 3, 2012 22:43:19 GMT -5
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Post by ddub on Jan 3, 2012 23:40:30 GMT -5
Well that is exactly what I was somewhat wondering when I picked up this 72. Was it a left over Super Stinger chassis? So I posted a thread that I included a link to above and came up with the Sachs using the internal tank along with fairly common knowledge that the Super Stingers did also. I asked my self "WHY" on the Super Stingers but never really had an answer until I thought about the exhaust with the case of this 72. StingerIII, My exhaust for the 72 440 Sachs also exits out the front. Who came up with that design?  they could have just as easily used flex pipe over to the side. ?? I have some extra Super Stinger (basically will be left over tired parts from my two Super Stinger projects) that I am going to do a "mod" Super Stinger. It won't be real pretty, but it will be loud and fast and a total rider. The engine will not be original, but it will be a F/A pushing out about 80 hp. Should be a handful. But I was going to put it in a different 18 inch chassis, I might just use this 72 since the tank would actually be correct. Not that I would be "cloning" a Super Stinger, but if the exhaust doesn't work with the plastic tank. why reinvent the wheel. I am somewhat hesitant about "cutting" this 72 apart as I don't think there were a ton of the 72 wedge chassis sleds built. But I doubt that it will ever be highly desirable regardless. Decisions, Decisions. |
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Post by admin on Jan 12, 2012 6:18:50 GMT -5
Adding this from another thread, I think the major difference between the 69' and 70' Mark II and Mark III sleds is the Mark III has the 18" wide track and of course the tunnel is wider because of it. Also, I think the Mark III has the storage compartment under the seat whereas the Mark II is a 15" track with no storage compartment. One other note, the 69 Mark III I have has the seat hinge on the side of the seat whereas the 70' Mark III has the Seat hinge on the front of the seat! The 69' models have the ignition key mounted in the hole on the right side of the hood whereas the 70' has the key mounted in a metal plate that is welded to the handlebar support. This difference is probably because the 70' has the hinged hood, so they did not have to make the ignition switch wires longer to accommodate a moving hood because they mounted the ignition switch on the handlebar support that does not move with the hood. Read more: www.scorpionsleds.proboards.com/index.cgi?action=display&board=general&thread=47&page=1#ixzz1jF3X754Y |
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Post by mooreperformance on Jan 18, 2012 19:59:27 GMT -5
Back in the day I remember hearing about Scorpion testing the 440 Sachs on the engine dyno. They realized that a "Y" pipe in the exhaust system killed some horsepower. They found that the dual inlet Donaldson muffler really worked well for that engine. To get that muffler to fit on the sled they needed to run it forward and low. When the plastic tank was used there wasn't enough room for the muffler underneath the wedge hood. It would have been much easier to make all sleds the same (with the plastic tank) and run the single "Y" pipe exhaust out the side like the CCW engined sleds. Scorpion made the effort to build a special chassis (with the steel tank) for all of the 440 Sachs powered sleds.Those 440 Sachs sleds sounded (still sound) real mean with that dual inlet Donaldson muffler! That dual inlet Donaldson muffler is still the best "can style" muffler available. As a side note: Although most modern snowmobiles run a "Y" pipe with a single expansion chamber type exhaust, all two stroke engines run much better with a separate exhaust for each cylinder and no "Y" pipe! Two strokes hate "Y" pipes!!!  |
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Post by mooreperformance on Jan 18, 2012 20:14:20 GMT -5
The major improvement between the 1969 and 1970 Mark II sleds was the brake. The 1969 had a disc brake that absolutely did not function at all! The 1970 and newer models had the self energizing drum brake. Most people think the drum brake is cheap but there was a big advantage to it. It would pull itself into the drum and self energize with a very light touch of the brake lever. When functioning correctly (when new) it was like power brakes. Much easier to operate than non-hydraulic cable operated disc brakes.
My brother-in-law ended up with a hole in his knee cap from ramming it into the ignition key on his 1968. The key was mounted on the hood in a bad spot.
Scorpion relocated the key (on 1970 models) inside the hood on the steering support to prevent that from happening to other riders.
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Post by ddub on Jan 18, 2012 20:45:46 GMT -5
MP, I think anyone with a 69 or older will vouch that the brakes on them, well just plain suck. |
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Post by admin on Jan 18, 2012 21:51:46 GMT -5
Excellent stuff. I wondered why the Scorps post 69' for example "downgraded" from the disc to the brake shoe! LOL Just did not make sense until I read this. Of course, if they added hydraulics to the disc brake system, it may have been a different story!  |
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Post by mooreperformance on Jan 19, 2012 17:25:23 GMT -5
The first snowmobile to use the Gates Polyurethane track was the 1969 Evinrude/Johnson. In 1970 Scorpion and Chaparral started using the polyurethane track.
Scorpion needed to redesign the boogie wheel trucks to clear the internal drive lugs. Instead of the 2 and 2 offset arrangment they went to a 2 and 3 centered arrangment. The difference in stability (having each assembly three boggie wheels wide) was very noticeable.
The Scorpion rubber track had a heavy internal chain and really pulled hard. The Skidoo rubber track was lighter and would spin much more freely. This put Scorpion at a disadvantage in early racing. Scorpion sold replacement hard plastic drive sprockets to try and spin the rubber track with less friction (the rubber drive sprockets really created friction against the rubber tracks metal lugs) but they weren't much help.
When the polyurethane track was installed in the Stinger in 1970 the Scorpions really started dominating racing particularly in grass drags and the 292, 340, and 400cc oval classes (with the Sachs single cylinders).
Those of us that had 1969 297 Mark II sleds couldn't hope to keep up with the 1970 293 Stingers (with that poly track). They were much faster!
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Post by mooreperformance on Jan 19, 2012 18:00:22 GMT -5
The big news for the 1970 bubble hood scorpions wasn't just the polyurethane track on the Stinger but the introduction of the Torque Sensing Cam Clutch (the driven clutch on the chain case).
Prior to 1970 all Scorpions had a spring loaded Speed Sensing Clutch. The new Torque Sensing Cam Clutch would "up shift" much faster and "backshift" much faster.
The heavy spring in the old speed sensing clutch would really kill belts. It wasn't uncommon for the belt to blow up and almost disintegrate! Higher horsepower sleds (634 hirth) would go through three or four belts a season.
The Torque Sensing cam clutch really made the Scorpion L-arm drive clutch work much better.
In 1971 Scorpion built the "Rat Trap" clutch for racing. It was a copy of the Salisbury model 910 with H-arms and springs (the H-arms and springs looked like a mouse trap so Scorpion called it the "Rat Trap" ). It would engage very violently at 3500 RPM!
The "Rat Trap" was the forerunner of the Power Thrust I.
Scorpions Power Thrust I clutch was a much better clutch than the (copied) Salisbury 910 but there is no doubt that the greatest invention in the snowmobile industry was the Polaris clutch. That being said, the Scorpion Power Thrust I was one of the best!
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Post by stingerIII on Jan 19, 2012 20:48:36 GMT -5
According to legend during the development of the SuperStinger and an article photo copied
from an old magazine .
"Even Glen Gutzman,the president of the company,had a hand in the super sled's development.
Glen and the entire team had watched the ski raising torque of some of the competition's sleds and
decided they had to have their own ,so they developed the 'rat trap' clutch.Glen was one of the
originals of Trail a Sled and is a very good mechanic and engineer. He had a few ideas in his head about making a superior clutch to go with their super sled and finally came to the point of wanting to make a workable model. But he couldn't find the right kind of springs he wanted for it. One day he was in a local hardware store and noticed a spring on a rat trap that appeared to be what he wanted.He picked up the trap,snapped the spring a few times,smiled,and bought all the rat traps in the store.Lynn(Corzine) claims that
right now the clutch is a tremendous development,but the whole town of Crosby is unprotected from a scourge of rats.
If you see smiles on the faces of Scorpion people this winter,it probably won't be from the antic's of Corzine's Kamikazes,but will be instead a result of the performances of their SUPERSTINGER."
Whether it is true or not it makes for a good story.
(also can be found at David's Vintage Snowmobile page 433)
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Post by mooreperformance on Jan 20, 2012 22:17:53 GMT -5
In the summer of 1969 I visited a Scorpion Dealer (Vickstroms Scorpion In Anoka, Minnesota). Mr. Vickstrom was very proud to display the new 1970 Scorpion Stinger. This particular model had, what appeared to be, a 368 Sachs engine. The engine serial number clearly stated 368 cc's. We were soon informed that this was not a 368 but a special engine modified just for the Stinger.
For the previous season (1969) Scorpion listed in the accessory catalog a "GIT" kit. This was a kit available from Sachs engines. It included a high performance oversize cylinder, piston and high compression head. The GIT kit was available for the 297cc Sachs and the 368cc Sachs. The oversize cylinder brought the 297 up to 320cc's and the 368 up to 396cc's.
The Scorpion factory was custom installing the GIT kit on the 368 Stinger engines. The Stinger that we were looking at that day was actually an engine displacing 396 cc's!
Later in the 1970 production run Sachs started supplying Scorpion engines with the GIT kit pre-installed and it was clearly marked 396cc's on the engine serial number (I have one in my collection).
The 396 Sachs powered single cylinder Stinger was (and probably still is) one of the fastest single cylinder snowmobiles ever made. Most people feel that it was making a little more than 28 horsepower. The engine had a remarkable amount of low end torque, perfect for the low engagement speed "L" arm clutch of the 1970 Stinger.
One more interesting thing we noticed that day, there was a tube welded at an angle into the bottom of the belly pan. When asked about that extra tube we were informed that it was an exhaust outlet for a tuned pipe (expansion chamber) that was available as a dealer installed option. Talk about a sled ready for racing!
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they could have just as easily used flex pipe over to the side. ??
