polaris 800 crank dial indicator help

[agurdo17]

ok have to check with u guys on this one cause the number im getting seems kinda crazy.
i mounted the dial indicator and pointed it to the pto end right at the end. i pulled it over until i found the lowest spot and set the indicator to zero. then i pulled the sled over until it got to the highest spot and it got to the line before 10. which is .009? at that measurement i do not know how the sled is still together considering the tolerance is .0025. Did i do this right?

 

[sled_guy]

You did it right... assuming the indicator is mounted solid to the motor so no movement can happen and that the crank end is nice and clean.

I usually put the indicator on there and then have someone else pull it over slowly while I watch it. I don't zero it, just watch it move back and forth and see where the high/low spot is.

But you are right, .009" is a huge amount... I've never seen one over .006"... they usually break after that.

sled_guy

 

[Daggerboat]

I prefer to check it closer to the seal where the taper begins. Your reading there will be lower, but not that much lower....That is a lot of runout, how many miles on that crank?

 

[TOPGUN]

LOL , I just checked a reman from Adrein Bernard......6 thou right outta the box. Funny thing is they actually said run it and that most Polaris cranks came right out of the factory like that ,needless to say, still sent it back!

 

[zkbrmachine1]

I would be interested in how you have your dial indicator set up. Take a picture and post it. The problem is everything in the chassis is aluminum and there is nothing to mount the magnetic base to. I made a plate that bolts to the front and the indicatior base sticks to that. I just got mine back from SLP today. It had .002 runout before I sent it to them. Checked it today and .0002. Hats off to Myron at SLP and all the shop guys. Fantastic people to work with!!!! We are all assuming that you have the plugs out while you are pulling it over. RIGHT?

 

[agurdo17]

i clamped a metal plate to the aluminum plate under belt. set it up. checked it ten times all in different places on the shaft. .009 it was. how can u even measure .0002 i plan on trading it in on a 2008 iqr and turning that motor into an 800. i did top end 2 years ago and it has 175ish compression in each cylinder. never checked it after the rebuild. Finally understand why it runs like a raped ape after the rebuild. also overheats and is very finicky. lol

dont want to sell it to some poor kid and have him have to put another 2000 into it after it breaks

 

[sled_guy]

If it really has .009 then it is not long for this life.

sled_guy

 

[agurdo17]

tell me about it. i started it. ripped a wheelie across the yard and started operation part out lol

 

[larry.mahoney]

what broke?

Did you have any warning like vibration or something else? What broke? Did the pto break off leaving the case & crank ok, the crank bearing give or the case fracture? Any pics?
Thanks

 

[shawkins]

Oh, the joys of 800 big block cranks. I install the new triple wide bearings from the dragons on my 800 motors. Saves the cases and pto ends from being eaten out. After that the only issue that is left on the 800 motor is the end snapping off outside the seal. I have found too many of the so called upgraded pto bearings eating into the crank and cases with not very many miles on them. I have found that a crank with only .002 runout will ruin cases and PTO ends. By the time you get to the runout spec that Polaris recomends there is nothing left to rebuild. Your cases need to be line bored and you will need a new PTO end. As far as the ends go it is a crap shoot. I have busted them all from billet to stock. Buy the cheapest one.