[img]i/expressions/face-icon-small-confused.gif[/img] This may or may not be news to you 08 500 carb model owners,but just replaced my second sheared flywheel key in about a month and a half! IF just once,I would say a fluke,but not twice! On the Bst 40 carbs that are notorious for idle cable freezing,breaking the spring retainer under the carb bowl,and IDLING DOWN,you can have a serious problem if idle goes down below 700-800 rpms! Repaired customers machine today that sheared flywheel key when trying to start. Was running fine,stopped machine, then tried to crank back up and backfired and no start condition,flywheel sheared key and jumped time! I knew what it was since I'd already done the same thing to our shop "mule",demo 500 that ALL shops have for trailer hauling,misc work,etc. IF idle falls too low,when trying to start CAN put excess pressure on bendix and flywheel and the stress can take its toll on the flywheel,namely the woodruff key!! Sounds strange I know but I talked to a Polaris engineer today and he confirmed my thoughts on the matter! Make sure the idle is at least 1000-1180 rpms and should never have this problem! I know some posters have changed out the cable for a fixed idle screw because of the idle and binding cable problem. I've never been a fan of the BST 40 carb,always liked the old BST34 with the separate floats and float arm,NOT the combined assy on the BST40,But the main problem is the cable adjuster! I dont initiate many posts BUT when I find something like this,I think the customers need to know,JUST as I explained to my customer! I dont delve into theory or try to explain things on a highly technical basis,I just like to report what I find and let the "brains" on the forum explain it maybe in a little more technical way than I do! Good luck opt

 

Thanks for the heads up OPT.

Couple of questions...

Is there anything that can be done to prevent this issue from occurring?

What do you recommend one does if one notices this issue? In other words, if one starts up their machine and they notice an extremely slow idle, what should they do?

Should they immediately shut the machine off and attempt to somehow thaw out the cable with some heat or deicer or something else?

How much of a job is it to switch out the cable to and idle screw? Would you recommend this? What's involved?

Thanks in advance.

 

Interesting, good post!!

 

Another good reason to have EFI?![img]i/expressions/face-icon-small-wink.gif[/img]

 

Is this just a 08 problem? What idle screw will replace the cable adjuster set up? I heard it was the screw from a 500 Predator,is that so?

 

Havent changed a cable adjuster out,but believe couple posters have used adjusters off the BS34 carb(not sure if threads are the same?) 08 models so far the only ones I've seen do this since the 500 came out (came to life as a 425 magnum in 1994!!!)

 

<div class="FTQUOTE"><begin quote>Originally posted by: old polaris tech

Havent changed a cable adjuster out,but believe couple posters have used adjusters off the BS34 carb(not sure if threads are the same?) 08 models so far the only ones I've seen do this since the 500 came out (came to life as a 425 magnum in 1994!!!)</end quote></div>

Can you recommend what can we do to prevent the problem, or take care of it if we notice extremely low idle. Just thaw out the cable/spring?

 

Just thaw out the cable/spring?

The spring adjuster set up notorious for corroding and just stops working. The pricey also $65 vs $5 for a plain idle screw.

All the spring set up does over a plain screw is allow it to flecks the idler adjusting **** out to the side for easier access, not worth it IMO.

Mine has not worked for over a year,I can turn the **** and it does nothing for the idle.

I did nothing about it, but of late the AVT is idling very low now,either the idle screw has to be set or the slack at throttle is off.

 

<div class="FTQUOTE"><begin quote>Originally posted by: TLC

Just thaw out the cable/spring?



The spring adjuster set up notorious for corroding and just stops working. The pricey also $65 vs $5 for a plain idle screw.



All the spring set up does over a plain screw is allow it to flecks the idler adjusting **** out to the side for easier access, not worth it IMO.</end quote></div>

So, I guess ole polaris tech meant that the cable seizes up because of rust???? Or is there water getting in there causing it to freeze? I wonder if there is a way to lubricate the setup to help prevent both?

 

I guess you can spray with something the spring connection every once in a while to hold off the rust. Odd it seems to be a 08 thing because I though nothing has changed on The 500 H.O since it came out in 98 on the 500 scrambler and 2001 on the Sportsman.