[i_play_bass]

So I removed my secondary on the weekend to inspect and to replace the buttons. Spring looks good, no real wear on the helix, just popped in the new buttons, clean up and a bit of grease and reassemble.

When it comes to preloading the spring, I gather that you want to hold the moveable sheave 1/4 to 1/3 of a turn counterclockwise (looking at the clutch from the backside) under spring tension so that the ramps on the helix just clear the buttons, apply some pressure to the helix to ensure it stays there while reinstalling the clip, and then it should only have movement in that counterclockwise direction, which adds more spring tension meant to provide resistance on the belt when under load? The tension can't get any lower because the buttons prevent the helix from spinning back clockwise (again, from the back side of the secondary).

If you don't clear the ramps past those buttons, the spring won't have that desired tension initially and the sheave will be far too easy to separate - belt slides right to the bottom quickly and you'll either burn out the belt or just not be able to go past a certain speed after maxing out the secondary's capability. You'll also likely be pushing the engine too hard trying to go any faster. I've heard it's practically impossible to "over-preload" the clutch by hand?

Am I on the right track here or missing any info? It's one thing to follow instructions, but I always like to ask "Why?". If you understand the why, instructions make more sense and are easier to repeat in the future!

 

[BC_Dan]

You probably won't be able to twist the spring to the second lobe on the helix. The spring will probably bind before you get that far. Twist until it clears the first set of ramps and you are good to go. It should only take about 1/3 of a turn of the sheave to get it to align.

if you had no preload on the secondary, the belt being dragged into the middle of the secondary by the primary almost instantly will cause a HUGE bog (like taking off in 5th gear). You will know instantly that something is wrong. Normal operation is a small pulley (primary with belt in the center) driving a large pulley (secondary with belt at the edge). That gives you the maximum gear multiplication of the variable pulley system. When the belt is pulled into the secondary and rides out to the edge on the primary, that's just the opposite and gives you the least gear multiplication. There will not be enough torque to pull the load and the engine will bog or die.

 

[i_play_bass]

Ok that's good to know!

I've got my new fuel pump on, oil pump adjusted, carbs off ready to clean again and see if all of this stops the low throttle bog/lack of idle.

Also picked up some new plugs and spare set - solids this time, the news plugs that came with it were the ones with the screw off terminals that always come loose.

Checked all my needles, all set to 3rd notch. I had one side that seemed to be running lean and two that were a little oily but I'll see if the carb, fuel and oil pump work help it out before looking at dropping any needle positions

 

[Coolhand]

Run some Iridiums in that thing, the amount of time you get out of them compared to standard NGK or any copper plug is worth it. I am running those or the E3 3.31 plugs which are nice as well. I have gotten 4-5 years out of a set of those and 3-4 years out of set of Iridium plugs.

 

[i_play_bass]

They'll make that big of a difference will they? I'll pick some up and keep the coppers as backups. I've never run iridiums so just never really dug into them

 

[Coolhand]

I've gotten that much out of them in my twins but in a triple yeah possibly. Worth a shot at least. I was fouling out standard copper plugs every 2-300 miles even with the right jetting in 4 different Polaris engines from a 400 to 2 440s and 2 500s with one being EFI . Switched to those and never looked back.

 

[Rasfaly00]

I have iridiums in one of my XC’s that have been in it for going on the third winter I’ve never had any issues with them.

 

[Coolhand]

One of the cheapest upgrades you can do. Someone once came on here and said Iridiums were bad for snowmobiles and could do damage to the pistons. Several of us laughed very hard over that one. 3 bucks for a copper NGK plug that fouls out or 6-7.99 for a Iridium plug for a long better burning and a heck of a lot longer usage out of them!