My old polaris was lost and forgotten for about five years. Then I got the notion to see if I could get it running. I think the lower seals are bad and I had a hard time finding the rebuild kit that I need. If anyone here can help me I'd appreciate it.
Thanks.

1990 polaris trail boss 250

 

you should be able to get a gasket kit from the net easily, maybe even ebay has them. a number of after market copanies would have some i would think. imo.

 

check out cheapcycleparts.com they have the oil seal kits for about 7 bucks. might as well replace the crank bearings too. try to wiggle the crank up and down to see if it moves. if it does then the crank bearings need to be replaced too.

 

Thanks guys.

 

Gussy, I'm reviving a 1991 trailboss 250 and found cheapcycleparts.com to have everything and is about 25% cheaper than my local dealer even after shipping.

I think I am going to find leaky crank seals on mine. There is a little movement and I can't get the machine to idle or start without spraying gas into the intake. It was sitting outside for a year before I bought it.

I have heard it is not that hard to change and you don't have to remove the engine from the bike. Can anyone give a quick run down of how to change out the crank seals?

My Haynes book doesn't explain it very well.

 

I second that, I have the Clymers manual and it is not very descriptive. I think it is a Yamaha motor on my polaris since the dealer always recommended Yamalube. If that is the case a friend of mine said he would change the crankcase seal.
Charlie, thanks for the site, I'm thinking about pulling the engine punching it out to around a 300cc, to make it a little quicker. I don't think it would even do a wheelie back in the day. I have a punched out suped up banshee, so I'm not losing riding time. The banshee is a workout though, always doing something with hands and feet. I want the polaris running so I can do some cruise a little more comfortably.

It would be nice to hear an actual persons description of replacing the seals.
Any help would be greatly appreciated.
Thanks

 

its not hard to replace just the seals but if there is wiggle room on the crank then the bearings are going out. not much use just replacing the seals because they cant flex fast enough to keep a seal around the crank. however just to change the seals is extremly easy. first pull the flywheel and stator plate. that seal will be staring you right in the face. take a seal puller or a screw driver and pry it out no big deal. take the new seal (make sure you match the one you just took out to the one your about to put in..they are different seals for each side) and find a piece of pipe that is the same size as the seal and long enough to reach past the crank end. lightly oil the outside and inside of the seal and lightly tap the seal into place. watch the orientation of the seal here.
for the other side, its pretty much the same but might be a little harder because of the clutch. you have to take off the CVT cover and remove the belt so its out of your way. next remove the drive clutch. that seal should be right there. again same thing as before just pry old one out. put new one back in. put everything back on and your good to go.