I need some wisdom. I have a 1998 scrambler 400. I took the flywheel off to try to get to the water pump. My water pump is leeking badley. I have 2 questions.
1. What is the easiest way to get in there and replace the water pump or what is leaking causing this.

2. How much play should the crankshaft have in it when I have it open like this. Up and Down and Side to side. I have the flywheel off and can see the magneto. Is this something I should be concerned about.

THanks Madvmax

 

If you don't have a manual its best to get one! Will explain a lot better than me taking a long post!There is an inner case behind the stator that has to be removed and the water pump is internal,driven off the counter balancer. There are 2 water pump seals and a bearing in the pump case,plus you need to check the balancer shaft end for scoring and wear where the seals ride. In the frame a lot of the time the top motor mount and the front mount have to be loosened to allow room for the case to clear the frame because the inlet neck usually hits the frame down tube. There should be NO play on the crankshaft end! If there is then you could have crank bearing problems. Again a manual will explain the details. OPT

 

That is alot of help. Yea i just pulled the scimatics on cheepcycle .com. and saw the seperate case. Does this take any special tools to do. What parts are needed to rebuild the water pump.

Second what do you recomend on the sllight movement on the crank.
This polaris is new to me. I just rebuilt the top end on it and as i was tunning it in the water pump was leeking really bad. It really sounds like a different atv, but thought i would make it right so before i move on i want to rebuild the water pump. This is when i tugged up and down on the crank. I am a very big person so when i grab it i probably yank harder then the average person.

Thanks you so very much for your time. Madvmax

 

Again,NO crank movement,must be tight with no movement up and down back and forth or sideways! If there is movement then the crank bearings are beginning to wear out and will destroy seals and will take out a new top end along with it! I've seen it too many times when people just do a top end and not take careful notice of the lower rod bearing or crank bearing play and end up back where they started,but this time only worse as they have an entire engine to rebuild right after they put good money in a top end!
Replacing water pump seals and the bearing just take regular hand tools,but there are 2 holes in the water pump housing that have to be left open when seals are installed,plus the two seals are different and must be installed correctly! Not trying to be harsh,but an inexpensive Clymer manual will pay for itself on the first job and will have illustrations along with instructions to guide you. OPT

 

FORGOT to also say when you might hit a "snag" on the repair or you don't understand a certain procedure, there will always be someone here on the forum to help you along as best we can! If uncertain about the crank shaft,just have someone experienced have a look at it,just trying to make sure the good money you've already spent doesn't go to waste like I've seen in the past! A new piston and cylinder can be saved even if the rod or crank bearings need to be replaced! Good luck OPT

 

THanks for your input. now were do i get the manual and how hard is it to change the crank bearings. AM i looking a a pretty tough job or is it pretty easy. Thank you also for the water pump info. THis is great. I am like a sponge soaking it up. Keep throwing it at me.

Thankyou Madvmax

 

The best are the factory manuals, they go into detail greater than say the Haynes or Clymer manuals but these help pretty well. To change crank bearings the engine has to be split,plus if you have to go that far,I would install a new rod kit. This involves a press,truing stand and dial indicator and best left to a dealer or machine shop unless you have these tools lying around!. Haynes or Clymer manuals can be found on E-bay and a lot of parts houses. Just do a Google search on your 98 Scrambler manuals and you should be able to get one fairly reasonable. OPT

 

Here is a link to a free down load of the factory service manual; I downloaded it a long time ago and it's been a life saver. If you go with the high speed down load, make sure you uncheck the SendSpace Toolbar or it will be added to your browser.

Download 1996-1998_POLARIS_SERVICE MANUAL.PDF from Sendspace.com - send big files the easy way