Polaris RZR Top End Rebuild | Part 6 in series | Partzilla.com


Hello, John Talley here with partzilla.com,
and welcome back to our engine rebuild project on our 2012 Polaris RZR 900 XP. As you can see, we’ve already got the bottom
end put back together, so now it’s time to get the top end done. So, let me go grab a couple of tools– more
than a couple of tools– a whole tool box– and we’ll get it put back together. Let’s go ahead and get the chain tensioners
in place. We want to go ahead and to the fixed one first. Go ahead and put in the one where we actually
have tension on it. These are both help in by just a couple of
6mm Allens. Now, we need to get the key put in. you want to lightly tap it in place, and maybe
tilt it towards the front just a tick that way it will ride over the top of it. We do want to put just a little oil on the
starter clutch surface right in here. Alright, let’s go ahead and get this intermediate
bearing on there– the starter. It’s held in by just a circlip. Alright, let’s put a little dab of oil on
the backside of where the taper is, back here, and then let’s get that flywheel on. Alright, let’s go ahead and get this flywheel
bolt back on. What we’re going to need to do is hold the
flywheel still with a strap and then put 133 foot-pounds on it. Want to make sure it doesn’t get caught up
on the chain. Now let’s see if I can get 133 foot-pounds
on it. Alright guys, well we got her on there. I about threw my shoulder out doing that. Alright, for right now we’re going to push
this to the side, I’m going to bring the teardown bench around, and we’re going to start preparing
the head. This was actually a very high-performance
engine that was built for it and the bottom end just completely let go as we saw, so I’m
basically taking it back to a stock configuration. This particular head has been ported. When I say ported when you look down the intakes
you can see just how much metal was taken out. And they actually did a really nice job. But the other thing I can’t really ignore
at this point it that they also decked the head. And what I mean by that is they took off a
fair amount of material on this side. that in turn raises your compression and if
you’re building a high-performance engine that’s what you want. Well, we’re not building a high-compression
engine. I want it to last. The other thing that that would affect is
when you lower the head, it actually shifts the timing so we’d have to have adjustable
cam shafts on this as well to correct for that. Well, we don’t. We’re putting back in the stock cams and the
stock cam shaft gear. so that being said, I’m going to put this
to the side and then we’re going to build this one on up from scratch. And you’re going to notice as I go along I’m
going to number everything: all the valves, intake and exhaust. So, let’s get these out of the way and we’ll
get started on that part. Could I have reused the valves out of the
other head? Yeah. probably. But, I want to be sure that this motor lasts
a long time. Alright, everybody’s back out. Now chances are this is going to be really
simple, everything should line up fairly well and have a nice groove in there. What we’re going to do just for fun is coat
one of these before it’s been lapped with what they call Prussian blue. what’s that? It’s a type of dye that actually shows you
where metal is making contact. So, let’s take one of our exhausts, and we’re
just going to lightly coat it. Go ahead and pop it in, and then we’ll be
able to see where all it’s hitting. Alright, one of two ways you can do this:
either use one of these little I guess you’d call it lapping tools that actually they attach
to the valve on this side via a suction cup, or just a quarter-inch piece of fuel line. Just slide it over the valve stem on the other
side and we just turn it back and forth a few times. Alright, let’s pop her out. Alright, we’re looking for a consistent blue
impression all the way around roughly the width of this tip of this pick tool. And that is pretty much exactly what we’re
looking at. That actually looks really good. so it’s not going to take hardly any lapping
at all to get this in there correctly. So, let’s get that cleaned back off and then
we’ll start the lapping process. Grab our valve. It doesn’t take a lot of this stuff. This is basically just an abrasive in a grease
base if you want to call it that. Alright, and now that we’re going to be putting
a little pressure on the stem itself, let’s go ahead and just put a little bit of oil
on it. Because the last thing I want to do is scar
that surface. Now you want to be very careful as you’re
doing this not to let any of that material to get onto the valve stem. That would be bad. Now when we start this off it’s going to sound
a little gritty and that’s okay– that’s what we want. But as I go further and further it pushes
more of that out of the way and it’ll start– you won’t hear it as much. See how it goes away? Now, just lift it up a little bit, get some
more of that material drawn back in, just like that. Alright, let’s pull her out. And that should take care of it. Now we want to make very sure that we clean
out all of that material because that would be catastrophic to say the least. Typically, on one that is as close as this
is, four to five times starting at the beginning, waiting for it to be quiet, that’s about all
it’s going to take. Just for fun, we’ll put the Prussian blue
back on there again and take one more peak. Oh yeah. Nice blue line all the way around. That one’s ready to go. Now, all I’ve got to do is do the same thing
for all the other ones. and then we’ll start actually installing the valves once that’s
done. Alright, so what’s next? We’ve got our valves lapped in. Next we need to go ahead and get in the seals. I wan’t ya’ll to be very careful about this. The older-type heads use this little small
seal. Well this is one of the newer type heads and
it uses a completely different valve stem seal. So make sure you get the correct part number
if you’re replacing the head. Alright, to get them on there, what we’re
going to do is just use a socket. Make sure it’s lined up evenly and just tap
it into place. Not a lot of pressure required. It’s basically replacing the seal and that
lower if you want to call it a seat that the old springs used. Alright, let’s get all of those put on and
then we’ll start installing the valves. Alright, when we lapped the valves remember
we had numbered each one. so I’ve got them laid out like they’re going
to go in. I still have my number on there. I do want to give them one last cleaning before
we go in. the reason you lay them out is not that I’ve
sprayed it with contact cleaner, if I get any on that bottom side, the number is going
to disappear. Alright, when you’re assembling this, use
just a little bit of this assembly lube to go onto the valve stem itself. Alright, after you put on your assembly lube,
just hold that seal in place and install your valve. Otherwise it’ll pop it right off. Now, here comes the fun part: each of these
springs is different from the top to the bottom. The bottom is where the springs or the coils
are closer together so you want to make sure that goes in first. Then your upper. And here’s the really fun part. This is when you need a third hand. I’m using the vice to at least hold the compression
tool in one place. Get it compressed down just far enough to
get the keepers in there. We don’t want to overcompress the spring itself. Alright, a little trick right here. Get a dab of grease, put it on the inside
of the keeper as you’re putting them in there. That way once they get actually near the valve
stem they don’t have a tendency to jump out at that point. Varying ways to do this: I typically get them
both at the top of that cup and then use just a pick tool to get them down into position. Once I get them in I usually just pop it just
a little bit to make sure they’re seated. Alright, now all I’ve got to do is do that
seven more times. So, let’s get it finished. Alright, we’ve got our valves in place, everything
looks like it seated correctly, now we need to work on setting the valve lash on this
particular machine. So, we need to get a baseline so we can see
what clearance we do have. What I’ve done is I’ve went ahead and pulled
out a full set of 250s– 250 shims. I’m going to go in and install all of those,
put the cams in place, and then measure to see what our clearances are and then add or
adjust from that point. So, let’s get it all put together and start
doing some measurements. Pretty easy. All you have to do is put them on top of the
valve and then they’ll just sit in there. Make sure they sit all the way down flat. Alright next, go ahead and put your cups in. Remember I had these numbered on the bottom? I transferred those number up top. Since they’re already numbered we’ll put them
in the places that corresponds. Alright, just to verify that you’re getting
the cams in the right position, the very end of the intake and the exhaust it’s a very
light marking. One ends in a 52 and the other one ends in
a 53. The intake being the 52. There’s your five-two. This is your intake. Alright when you’re doing this you just want
to make sure that the valves are pointed up. we’re going to go ahead and do our intake
side first. Lay our exhaust cam in there which we’ll get
to later. Now if you don’t have an angled set of feeler
gauges like this, I recommend that you get some. It makes life a lot easier. Alright. I’ve got my first measurement. What I’m going to do is just go around to
all of them, write down what that measurement is, and then we’ll go back and see where we
need to add and adjust the thickness of the shims. Alright, we’ve got everything measured. I’ve got them all written down over here. We started off with 250s across the board–
and that’s in all locations. What you’ll do is you’ll go to your chart,
take your measurement which in this case was .229, find the range that it is going to fit
in, which is going to be .226 to .250, and then you come across to the 250 range, and
that tells you if you come down that’s going to be a 258. So, I’m going to go back through, I’m going
to loft this off, go back through, and then I’m going to exchange my 250s for whatever
that chart tells me it should be. Make sure you keep everything in the same
order. Alright, we’ve got our new shims in place,
got our tappets in place. What I’m going to do now is go ahead and once
again put the cam in temporarily and then we’re going to check our measurements and
make sure they’re within range. Alright, once again when you make your measurement
you want to make sure your lobes are pointing up at the same angle as the valve stem itself. So about right there. And also remember that your intake and exhaust
have different tolerances. Your tolerance for your intake is somewhere
in between .125 and .175 millimeters or in between five and seven thousandths if you’re
measuring in inches. So, each intake needs to be one of these three. Let’s see where we are. Alright. Right in the middle. That’s where I want to be. I’ll accept one of these other two but that
middle one? That’s what I want. Alright, the intake’s looking good, I want
to check the exhaust, and that’s going to be in between .275 and .325 millimeters, or
if you’re doing standard, 11 to 13 thousandths. All my measurements check out. So what do we need to do next? Let’s go ahead and take them back off one
more time and go on and get assembly lube on all the buckets, on all the the top of
the tappets, and then the bearing riding surfaces here and here. Well guess what? Now it’s time to carry it on over and get
it torqued down on the block, so let’s get that done next. Alright, I’m not going to need this plate
any more to hold it down, but we will use this plate for is it goes on the back side
of the cam shafts to hold them in place. There’s a couple of slots on either of the
cams that this will just slide into and hold them in place while we set the timing. Speaking of timing, let’s go ahead and bring
the crank around to top-dead-center. Alright, where do you find that? What you’re looking for here is a line right
here on the flywheel and you want to line it up where the case halves meet, so right
there. Alright, so that should be top-dead-center
for us. Now, we can go ahead and get our head gasket. Get that on and then actually lift the head
onto the cylinder. Alright and this just goes on dry. Make sure the surfaces are clean and lined
up with the dowels. We’ll just lay the chain right there and just
grab it in a few seconds with a magnet. Let’s tap it and see if we can get her to
sit down. Alright guys, time to go ahead and put in
our head bolts. Polaris does require that we install new ones
because these are stretch bolts and once they get stretched that first time can’t really
reuse them again now can you? Start off I’m just going to get them in there
hand-tight and then we’ll start going through the process of getting them torqued down. Alright the tightening sequence is thus: 1,
2, 3, 4, 5, 6,. And there’s two stages: the first one we’re
going to take it to 21 foot-pounds. Alright next, we want to take it up to 26
foot-pounds. Same sequence. Alright, step three or stage three, is 180
degrees now. So start off here, pick out another point,
180 out. There she is. While we’re at it, let’s go ahead and get
these two on the end and the torque on these is 89 inch-pounds. Next, let’s go ahead and get some lube on
our cams. Get it on the lobes, the bearing surfaces,
and get them installed. These carrier bolts are also set to 89 inch-pounds. I don’t want to torque them quite yet. I just want to get them held in place. Next let’s go ahead and get these cam gears
off. Probably could have done that before. Alright next, let’s get this plate I was talking
about earlier installed on the exhaust side. It’ll just slide in. On the intake you’re going to have to use
a wrench. Bring it up just slightly and that’s going
to be where they need to stay while we set the timing on this thing. Alright, we want to start with the intake
gear first. The difference is one has an “E” and one has
an “I” stamped on it. So, it didn’t matter if you didn’t keep up
with which is which. What we want to end up happening is we want
the intakes to be sitting in there like that when the chain is on. So, let’s grab our chain, put it where we
think it’s going to be and verify that you’re at top-dead-center down here. what we want to go ahead and do is get that
top bolt in. Alright, with that one in place let’s go ahead
and grab that exhaust gear. Alright that’s a little bit off. So move it over one tooth. Alright, we’ve verified our marks. What I want to do now is go ahead and torque
these down to 14 foot-pounds. Alright, we can go ahead and remove this plate. Bring around so we can get those other two
bolts in place. Next, let’s go ahead and get our cam shaft
carrier in place. A little assembly lube on here, here as well. We have to knock them around a little bit
to get them to line up. Alright, don’t forget your upper cam chain
guide. Now remember we need to tighten all of these
and of course there’s a sequence. Alright, all of these are going to be 89 inch-pounds
and they go something like this: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, then 11 12 up here. So let’s get these things torqued down. Alright, with all of those torqued down, let’s
go ahead and get our cam chain tensioner back in place. Make sure that little crush washer is still
there. Alright, so 27mm, and she takes 29.5 foot-pounds. That’s it. Alright, now it’s going to start getting a
little bit easier. Let’s go ahead and get the valve cover back
on, then I’ll bring over the– this cover which has the stator in it, go ahead and get
that mounted up. And guys we’re going to be getting dangerously
close to actually taking it off the engine stand and getting it back in the machine. So let’s get these couple of covers put on. Alright, we’ve got our seal in place, let’s
go ahead and get the cover on. Hopefully this will be the last time I ever
have to look in this engine. And I went ahead and replaced these upper
cushions because those old ones? They were kind of crunchy to say the least. No real magic here. Just tighten them until they bottom down. Let’s go ahead and get our idler gear in there
and get that magneto cover on. Alright, when you’re putting this thing on,
there’s some powerful magnets in it, and you do not want to get your fingers to get caught
in between those two edges so be real careful when you’re doing this. See what I’m talking about? The absolute last thing you want to do in
this stage of the game is to drop anything into here, because that’s basically the bottom
of the engine, so let’s cover up that hole. Alright, all these are set to 106 inch-pounds,
and of course like all the other ones they have some weird pattern about it which I’ve
drawn on the cover itself. Well guess what kids? We’re actually finished with the basic engine
build. So what’s next? Well, I’m going to get the machine back in
here and then we’re going to start getting everything hooked back up to this. the intake, the water pump. Then we’re going to get it slung into the
frame and get it fired up. So I know you want to come back to the next
installment and see that. Well, if you need and of the parts we used
to get it this far, come find us at partzilla.com and we can get you taken care of. If you have any questions or comments just
leave them in the section below and I’ll do my best to answer them. And until next time, we just want to say thanks
for watching.

22 thoughts on “Polaris RZR Top End Rebuild | Part 6 in series | Partzilla.com

  1. Excellent video's, John's attention to detail and straight forward approach to engine rebuilding is a welcome change to some of the stuff you see online…….much appreciated and thank you.

  2. Question I'm redoing my pistons and rings would you do a valve job also or just adjustment if the head seems to be in good shape.
    Also what's your take on converting my razor to the big bore 935cc kit

  3. Thank you for the advice when I vent to re shim the valves I noticed there r no shims. I was told that I have to get whole new cups that have a different shim size build in have you guys heard of that

  4. Great video. I run my own shop and buy all my parts through Partzilla. Thank you for this knowledge and great oem parts. Bill

  5. I just rebuilt a 2015 Polaris ranger 900 and did a bench compression test and found 145 psi on one side and 45 on the other could the shims possibly be the culprit? and where can I purchase the shim kit. thanks

  6. great videos but I aliens my rzr 1000 with the way you showed to get it on top dead center and my number one piston was about half way up to top so I was wondering if maybe the 1000 timed differ ant than the 900

  7. I thought I'd let everybody know that on a 2014 rzr 1000 the top dead center is not like this the line on the flywheel is pointing straight up

  8. Quick question. Just rebuilt 2012 900xp. Set valve lash on intake @.006 on all 4 and – .012 on exhaust. When i was running engine after a day i notice some valve ticking(rattle) in the top end so i pulled valve cover back off and while the engine was slightly warm i re-checked the intake and now i have .008 on 3 valves and .007 on one. And on the exhaust i now have .014 on 2 and .013 on the other 2. I realize its warm and that can change it so i let it completely cool back down and im back to my first readings. Is this normal to have the clearance get larger when the engine is hot? And also John is it ok to hear some slight valve ticking(rattle). Thank you and I appreciate your detailed videos.

  9. Did you torque the cam caps when measuring valve lash or can you leave them snug, measure then torque when complete?

  10. I am wanting to buy a polaris Rzr 900 xp that a guy is selling for 1300 but I am afraid of not being able to do the rebuild; last time I went and looked at it. The guy said it ran but was knocking, so we got it started but died on us three times, the third time, starter wires got hot and we noticed it was locked; Whats your opinion? Thanks very excellent job. I have watched the videos a lot, trying to memorize the procedure.

  11. The alignment plate that was used to set the cams, anyone have a part number for that tool? is it something home/ shop made?

  12. hi i m rebuilting an rzr 1000xp with a sparks big bore kit are all the t0rk specs the same for a 900 an a 1000 an by the way a great video thank you for all the info

  13. Hi I was wondering what grit lapping compound I should use I’m rebuilding a 15 ranger 900 xp all my exhaust valves got bent thanks in advance

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