Just get the rust off the bearing,oil it up and spin it. You can tell real quick if it's smooth or rough. Once the cases are assembled,if the crank is a little stiff when rotating,whack the end of the crank shaft with a dead blow hammer. This helps align things back up.

 

opt thanks for your help once again invaluable. but you didnt answer the question about the engine balancer or do you not remember/know.
THANKS AGAIN
RUBEN

 

If you're talking about the small bearing in the water pump housing,yes it sits flush with the back of the housing as best I can remember. Main thing is to not block the small hole in the housing.If it has to hang out a tad,no problem.
"To assemble the pump casing,
press the bearing into the casing
until flush with the casting. Note:
Do not press the bearing in until it
seats against the shoulder, or the
oil hole will be covered by the bearing
outer race. Next, press the oil
seal into the seal bore until the
weep hole is visible. Now press the
water seal in until flush with the outer
edge of the seal bore."

When in doubt,read the manual...

 

 

thanks opt but i was talking about the bearing from the engine balancer but i got it figured out.
THANKS
RUBEN

 

Only other bearing is the small inner case bearing and it fits flush.

 

yeah thanks opt i got it, but im just hoping that the outer half of the crankcase bearing is good if not man thats another $Jackson$ that I have to spend man im talking about 400- 500 on the engine repair not including all of the labor that i have/still need to put in. man i couldve bought me a whole other 4 wheeler.
oh well i love my old polaris scrambler and wouldnt trade it for anything(perhaps a newer scrambler),lol.
THANKS
RUBEN

 

When I rebuilt my first 350 engine over 24 years ago I realized then I'd rather rebuild a four stroke any day of the week Way more moving parts on the 350 and 400 than the average 4 stoke engine and if you're going to play with these engines be prepared to pay also.. Admittedly the acceleration is wicked on these things and power to engine weight is great,a lot of hop up parts are available,but you just have to stay on top of maintenance and repairs.A lot of people still think they're worth it though.

 

I like the Polaris 400...have had many...responds really well to porting/polishing and have been very reliable (for me at least)...

 

i was 2smoke for years untill i rode and worked on a 4 stroke..i doubt ill ever go back