I started this thread because we have so many sled powered threads...maybe it will become a sticky...
I can no longer shift and hang onto the wheel, so sled power is the only way to go, plus I've been using sled motors in my buggies for almost 20 years...Here's my approach...I mainly only buy whole running sleds...So I can take it out and give it a thrashing, I recently came up with a way that I can hang on..I rigged up a safety harness, with a short teather clipped to the steering coloum, that allows me to "hang on" without hanging on so to speak...Anyway... I look for sleds in the late spring and early summer...People are thinking about boats and such, and dealers don't want to store the sleds till 1st snow.
I tend to look for 90's sleds due to the fact that the tracks, suspension, and ski's are worn out driving the price down, but we don't care about that part of it anyway...I like it when the owner tells me that it's been fogged so it will be hard to start, and pulls the plugs and lets you see them...they will have a film on them.. meaning it was stored propperly...
Next I look at how much crap and debris is laying in the belly pan, if it has half decayed leaves and cat tails I ask about maintenance like when was the last time it was greased?...Just a side note cracked up hoods and torn up seats are not really an indicator to how the sled was treated or maintaned...just that it has been rolled or the dude had a hungry dog, and polaris seats always tore at the back...
Now to the good stuff...I always give the clutches a good looking over for scratches and dents on the sheave faces this is usually caused by using a prybar to put the belt on instead of rolling it on...Dents from pounding on the clutch instead of using a puller, remember these motors have delicate seals in the crank case...Also take a look at the belt if it's really worn or chunked out the owner may not have kept up on other things. Keep in mind the belt and the clutching dictate the perfomance of the machine...
Next I whip out my minni mag and look down the spark plug holes, there should be no chips/dents/damage of any kind...and they should have a nice even black covering of carbon...Now there maybe less on one side due to the intake charge washing some off...thats okay, while looking down the plug holes use the primary clutch to turn the motor and take note to how smooth the motor feels if it feels notchy that could be a bearing or crank problem...
If the motor has black drool under the exhaust, thats okay but if it has washed looking lines that shows a serious flooding problem in the past I'd ask the owner about the flooding,or it has been run with bad exhaust gaskgets...most sled engines have a couple of drain plugs on the lower crankcase half that really helps to get the motor un flooded...Look over the coil packs,control cables, and exhaust pipe...If the cables look okay move on to starting it up...
Listen carefully as soon as it fires, you are listening for exsessive rig slap and for wrist pin tinging, don't close the hood yet since the rear of the sled should be off the groound already for storage (so the track doesn't rot or flatten the lugs), rev the motor just enouph to get th primary to close enouph to pull the secondary at a creep, look over how the cluches look when turning slowly, wobbles are BAD, let the motor warm up breifly keep in mind it only has heat exchangers so will overheat quickly if you let it run too long... give the motor a stab on the throttle take note of how it sounds and pulls and how the clutches react..( keep in mind it may be slightly rich )
Most owners get pissed if you do this but if you can't take it for a quick spin on the grass this is the next best thing...get some pressure on the brake to simulate the machine pulling it's weight and rev the motor to overcome the brake...but don't loose your mind and ride the brake till it smokes, a motor with weak seals may sound great with no load but have no power when working... Unless you have the tools seals need to be installed by a dealer or pro shop...and gets spendy fast... next shut down the motor and check the cylenders for even heating one hot and one cold could be a cooling problem or a compression problem...becarefull when doing this, I like to pull the plugs and give them another quick look, alittle wet is usually okay but look over the whole motor for coolant leaks,etc...
I hope this helped clear up some questions that are floating around out there, I haven't had any expeiance with the new 4 strokes but there are a few here that work with them and I hope they chime in
