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7043342 Black - 3342
NOTE: Springs listed as color - #### will have the last four digits of the part number painted on the spring coil. Tag each spring with the part number and spring force when not in use.
From: www.mxzx-revzone.com/iq.htm
Spring "Rate" & "Forces" - Definition
Here is my top pet peeve. When it comes to springs and their forces, I always hear or read the word "Rate" when the word "force" should be used. Here people describe a quantity of a spring and are not referring right to the element of the spring.
Rate is the fixed ratio between two things. In the case of a spring, rate is the quantity lbs measured per inch of change. You compress the spring it takes "x" amount lbs of force (per inch) to change the height of the spring.The starting point is the installed height and the finish point is the full compressed height. The installed height is at rest or the engagement or beginning of the shift. The full compressed height. is at full shift.
Force is the strength or energy exerted or brought to bear to hold something in position. For example a 170-300 primary spring. The spring needs 170 lbs of force to keep it at installed height and must add enough force of up to 300 lbs to change it's position to full compressed height..
***The spring does not have 170 lbs "rate" at the beginning of the shift.
The spring at installation is compressed 1.25" and requires 170 lbs of force to keep it that position.
The spring at full shift is compressed to 2.5" and requires 300 lbs of force to keep it that position.
To figure out the rate of the spring you do a simple calculation.
i]300 lbs - 170 lbs = 130 lbs
ii]2.5" - 1.25" = 1.25" of distance travel between engagement and full shift.
130 lbs / 1.25" distance = 104 lbs/inch of rate.
From installation height of 1.25" then you want to compress it just 1" more, you would have to add another 104 lbs on top of the 170 lbs to make the spring compressed to 2.25". To keep the spring compressed at 2.25" that would mean you did 170 + 104 = 274 lbs to keep it in that position.
Getting back to my pet peeve about "force" and "rate" example:
Q]...Change to a softer spring, one with less finish rate in the primary. Softer primary spring has faster up shift.
A]...For fun to talk of the 170-300 spring, the idea given here is to lose the 300 and go with something lower. For lack of better numbers lets say "260".
Might want to change to a 170-260 from a 170-300.
Now that you know the definition of rate, what do you think when you read this quote where the word "rate" is used? Right idea, however not using the correct term. I'd like to correct the
Q] by having the word rate exchanged with "force".
New Q]...Change to a softer spring, one with less finish "force" in the primary. Softer primary spring has faster up shift.
Back-Shifting
Back-shifting occurs when the track encounters an increased
load (demand for more torque). Back-shifting is a function of a
higher shift force within the driven clutch then within the drive
clutch. Several factors, including riding style, snowmobile
application, helix angles, and vehicle gearing determine how
efficient the drive system back-shifts. The desired engine
operating RPM should never fall below 200 RPM when the
drive system back-shifts.
Drive Spring
The drive spring opposes the shift force generated by the clutch
weights, and determines the neutral RPM, engagement RPM,
and wether the engine RPM remains flat, rises, or falls during
shift out. When changing only the drive spring, installing a
spring with a lower pre-load rate will result in a lower
engagement RPM speed, while installing a spring with a higher
pre-load rate will result in a higher engagement RPM.
11 Series Weights
WEIGHT GRAMS(+/- .8g) PART NUMBER
11-40 1322593
11-42 1322592
11-44 1322591
11-48 1322590
11-50 1322589
11-52 1322595
11-64 1322604
11-66 1322559
11-68 1322558
11-70 1322523
11-72 1322524
11-74 1322525
11-76 1322526
10 Series Weights
WEIGHT GRAMS(+/- 1g) PART NUMBER
10M - R 44 1321530
10M - W 46 1321527
10M - B 47.5 1321529
10M - 5 48.8 1321528
10M 49.5 1321531
10A - L 51 1321531
10 51.5 1321526
10A 53 1321589
10-54 54 1321685
10-56 56 1321684
10-58 58 1321588
10-60 60 1321587
10-62 62 1321586
10-62M 61.5 1321614
10-64 64 1321585
10-64M 63.5 1321615
10-66 66 1321584
10-68 68 1322427
10-70 70 1322414
10-72 72 1322428
10-74 74 1322429
10-76 76 1322585
10-78 78 1322586
11 series weights
When compared to a series 10 weight, the series 11 weight has more weight distributed at the beginning of the profile curve and does not tuck under as much as the series 10 weight. Because of this difference, the belt--to--sheave clearance must be checked and
washersmay need to be added to increase the belt--to--sheave clearance after installing any series 11 weight into a drive clutch that was previously equipped with series 10 weights.
The procedure for increasing the belt--to--sheave clearance by adding washer(s) to the spider is outlined in all Polaris snowmobile service manuals.
When cross--referencing between series 10 and series 11 flyweights, a series 11 flyweight will function similarly like a 2—gram heavier series 10 weight. For example, use a 11--68 when replacing a 10--70 flyweight.
I used the almond last year, and it worked pretty well for my setup. However in other threads talking to Ron I have put in the Polaris black/green and I can already tell you the engagement is almost 800 rpm different. It used to be approx 4200 rpm now it wants to engage at 3400 rpm. I'm looking forward to getting all the low end torque I can out of the old tractor!!
Thanx Ron,
-T
i wasnt getting enough rpms out of the almond so i chaanged to the slp blue pink and runs great .