i have a 1987 formula mx 440 ski doo sled and it idles high and iw as wondering if anybody knew what the rpms should run on when idleing cause mines on 40 when it idles and how can you turn it down. plus my brakelight dont light up so im thinking bulb does anyone know where to find a bulb for it and im new with sleds but mine sucks at turning and i was wondering if it suppose to be like that or i need something thanks email me at hostetler_truck@windstream.net if u can answer me

the bulb is a 1157 standard auto bulb. rpms sound kind of high but I am not sure of the spec. check the wear bars on the bottom of the ski's to see if they are wore down. the mx is the rotax type 464 :confused: I may be wrong on the type number . been to long since I looked at mine. they are 470 class sleds though. I have a spare track I would sell, if you need one. enjoy it they are pretty quick for the day and size. have great transfer on launch.

I have an '88 and am the original owner. Dooman is correct on all the advice. The rear bulb is an automotive 1157. The engine is a type 467 but actual displacement is 462 cc's. Check the ski wear bars for excessive wear to return steering control. The sled turns pretty well when everything is in good order. The idle speed, according to the book, should be 1800 - 2000 rpm, the air screws should be 1.5 turns open. If you have trouble getting the idle speed in spec using the idle speed screws when the carbs are set close to factory specs then I would start looking for any type of air leak whether it be crank seals, carb boots, etc. Also make sure the engine temp is in the normal operating range and not too high when attempting to make idle speed adjustments as a high temp can make the motor idle faster than normal.
These are fun sleds and relatively quick given their age, size, and weight. Mine has never fouled a plug, never a leaking carb boot or crank seal, and always starts and runs well after one or two pulls barring any operator errors. I have nothing but great memories from that sled, hence the reason I kept it so long. Hope this helps.

well where is the carb adjustment i cant find it on the sled anywhere is it visible?

You will probably need to remove the big plastic air box from the top that goes over the carbs so you can see them. It will take a long flat blade screwdriver to loosen the band clamps that hold the air box to the carbs. I would also suggest buying yourself the Clymer manual that covers 1985 -1990 ski-doo's. For what it costs it will save you immensely in both headaches and labour costs to do some work on it your self. These manuals have great step by step photographs for those of us who aren't mechanics.

Before you start any carb adjustments make sure your throttle cable is adjusted properly so it pulls both carb slides simultaneously, and that there are no hang ups that would, or are, causing the slides to not travel smoothly through their entire range. For example, if the cable or slide or slides are hanging up somewhere they cannot return fully to the idle position and the idle stop screw. This may be the cause of the high idle also.
The carbs are in front of the airbox. They are visible without removing any parts. They should be Mikuni 34mm roundslides. On one side of each carb body is an adjustment screw going into the round housing for the slides, these are the idle speed adjustment screws. Toward the engine side throat of the carbs, entering at an angle are the air screws. If you still can't find the screws, and they're not hard to find, I can send a small Mikuni manual to your email.
Also, be sure to make all your carb adjustments with the airbox installed.
Ideally, if the carb adjustments get you where you want to be, then it would be wise to have them synchronized for best performance. Synchronizing carbs isn't as painful or expensive as the name may imply.
Hope this helps

can you send me an manual picture of the carb so i can find where the adjustment is on it thanks

I just sent a .pdf copy of the manual to the email address you have in your first post. That should help.

It sounds like your carbs are gumed up , I would add new gas and a good carb cleaner and run that be fore any thing . Drain the gas if its old.