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Discussion Starter · #1 ·
Hello there, after a 20+ year hiatus from owning my own snowmobile I decided to buy myself a cheaper sled to play around on this year. I bought a 97 Formula 500 deluxe. Sled has 7300 miles on and besides the carbs needing to be cleaned it runs pretty good and has been fun to get back in to riding again. The only big issue I have is the rear suspension squats to the point the flap drags the snow and after riding for a little while my back looks like the trail. All covered in snow and ice. I have adjusted the rear torsion spring adjusters to the highest setting and still squats down. Is there any heavy duty torsion springs I can replace the old stock ones on the sled now? If so I am having one heck of a time finding some.

Thank you in advance
 

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Yes. There are springs available. What's your suited up weight? The heavy springs are for the big boys. You may just need new ones.

And welcome to dootalk.
 

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Discussion Starter · #3 ·
Yes. There are springs available. What's your suited up weight? The heavy springs are for the big boys. You may just need new ones.

And welcome to dootalk.
all suited up I am around 250lbs. I realize that springs do wear out so that was why I was asking about either replacing them or upgrading to heavy duty springs
 

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The springs do lose their springiness over time, especially if the load isn't taken off in the off season. At your weight replacing with the heavy duty torsion springs is a good option to get things to ride right. Your choice of sled for getting back into the sport is a good one. We used to have a '97 Formula 500 in our fleet and I got the opportunity to put a fair number of miles on it. It is a fun 500, reliable and perfect for trails. The only thing we had to watch out for was harsh landings because it seemed to bottom out easier compared to the same chassis MXZ's.
 

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I'm 250 with all my gear, and the torsion springs recommend for me (by members here) were the heavy duty ones.

503189674 and 503189675

140 -190 lbs 11.11 x 95* - Part # 503189443 and 503189445
180-230 lbs 11.11 x 90* - Part # 503189522 and 503189524
220-270 lbs 11.11 x 80* - Part # 503189674 and 503189675
260- 310 lbs 11.11 x 73* - Part # 503189992 and 503189994
 

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Discussion Starter · #11 ·
if its changing from start of ride, to middle of ride; that is the shock, not the spring.
As soon as I sit on the sled the flap is dragging pretty good. When I get off the sled it comes up but not all the way up. I can lift on back grab bar and raise it up another 1-2".
 

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Discussion Starter · #12 ·
The springs do lose their springiness over time, especially if the load isn't taken off in the off season. At your weight replacing with the heavy duty torsion springs is a good option to get things to ride right. Your choice of sled for getting back into the sport is a good one. We used to have a '97 Formula 500 in our fleet and I got the opportunity to put a fair number of miles on it. It is a fun 500, reliable and perfect for trails. The only thing we had to watch out for was harsh landings because it seemed to bottom out easier compared to the same chassis MXZ's.
So far I am really impressed with this sled. It has plenty of power for trail riding and easy to throw around in corners. I have around 400miles on it since the trails have opened up this month. This spring I plan on going through the clutches and carbs. Otherwise a great running sled for having 7400 miles on it.
 

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Discussion Starter · #14 ·
So it looks as our riding season has come to an end with 3 days of mid 40's and lots of rain. Had a great time and put on a little more than 600 miles on the trails. Going to look for springs this off season and go over the sled and check everything over. I did a compression test on it today as it still has low end throttle issues. Compression is 65psi on pto side and 63psi on mag side! How does it even run with that low of compression? I am sure I read on here that a 2 stroke should have above 90psi to run. So it looks like I will be doing a top end rebuild this off season as well.
 

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65. Yep. Become friends with the parts counter dude/dudette.

Do yourself a favour, do the rotary valve drive seals at the same time. Sometimes they'll get overlooked. Its been 20 years since I had one apart, but IIRC its 2 o rings and a paper gasket. Check the brass RV drive gear on the crank as well while your in there that deep.
 

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On a side note, I upgraded to an SC10-III skid in my sled so those part numbers I posted were for an sc10-III, not sure they will fit the skid in your sled.
 

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Discussion Starter · #18 ·
65. Yep. Become friends with the parts counter dude/dudette.

Do yourself a favour, do the rotary valve drive seals at the same time. Sometimes they'll get overlooked. Its been 20 years since I had one apart, but IIRC its 2 o rings and a paper gasket. Check the brass RV drive gear on the crank as well while your in there that deep.
It was suggested by a guy I know that works on Skidoo's to do the crank bearings and seals right away as its not that difficult. I am a mechanic in a factory so i thought I would give it a try
 
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