Good morning, First post here, but have got a ton of great information off this forum, so thanks to all of you who contribute. But there is one thing I just cant seem to get a firm answer on:

I am rebuilding a 1995 Polaris Xplorer 400. I tore it down to every individual part. Previous owner swamped it, and let it sit for years. It needed major cleaning and tons of new parts. I have got to the point of reassemble and realized in my eagerness, I didn’t mark anything on anything to do with counterbalance and crank gear alignment. There are no marks or dots on anything. Everything was rusty, so media blasted most of what I could. How do I figure the alignment up based off of crankshaft position and counterbalance position "ONLY"? Your assistance is greatly appreciated.

 

You're not the first one to do this. Some were marked,but most weren't. Best place I can tell you to call is these guys as they rebuild them for a living. The c/b weighted(heavy end) normally lines up at the bottom of the engine case at the same time the piston hits tdc. This is to offset the engine vibration,but being off a tooth or two would be noticeable I'm sure.Give these guys a call to see if they can be more specific. http://www.ebay.com/itm/Polaris-ATV-400-350L-counter-balance-shaft-water-pump-REPAIR-balancer-/300941567648?pt=Motors_ATV_Parts_Accessories&hash=item461183e6a0&vxp=mtr

 

I've got parts lying around I can check the timing mark versus the key in the gear.
all mine have been marked.

 

ok the punch marks used to align the gear to the counter weight of the balance shaft, are in line with the heavy side of the weight.
the mark on the gear of the balance shaft to time it to the crank gear., is on the a gear root. there are 17 teeth between there and the gear point which is in line with the punch marks in the center. i'll try and post pictures

the drive gear on the crank is marked on the gear point which is inline with the drive key

 

https://skydrive.live.com/?cid=15e3f...E3F35BCEE13CC5

 

Thanks for the replies. I have saved several threads on this topic. some with pictures. I took all the information and came up with this.. I placed piston TDC, counterbalance wieght facing the 6 o'clock position. I marked the CB gear at 9 o'clock position, counted up 7 teeth, and made that my alignment mark. Then lined that mark up with my TDC mark on the crank gear. Does that sound anywhere close? I got it all together and running, and there is a little vibration at idle, but with a little throttle smooths right out. I always remembered my 2 stroke snowmobile having a little vibration, so I dont know if that is character to 2 stroke, or if my theory and research was wrong on the CB. Without tearing it back down and looking at it, I cant compare it with your gear count. So Im hoping you can look at yours and say its good, or this is what I need to do... Thanks again for the help

 

With the crank half way through the stroke. And the counterweight of the crank toward the back
In this position the balance shaft should oppose it.

With the piston tdc- cb shaft 6 oclock
Btc crank -cb shaft noon

I can't tell if it is exactly that. Maybe one tooth either
but probably not.

Have the factory centerpunch marks rusted away.
What's left of the gear.

 

400l2stroke