Author Topic: Old Oil Polaris Rebuild (Read 13615 times)

Skipper · « **on:** Jan 18, 2009, 10:32 AM »

I picked up an old (90' or 91') Polaris Indy 500 2up for scrap price with a melted down motor. The chassis are in pretty good shape, so I am beginning to overhaul the engine from the crank up. I am going to bore the cylinders and have a machine shop check the crank and bearings out. I will have a good chunk of money into this project, and I would like it to last me a few years.

My question is, what about the oil injection? I don't like how it is set up, and I am unsure if it should be replaced. I have a few people telling me to disconnect it and mix the gas. I have no problem mixing, but I would like a few opinions for you guys. It is as simple as plugging the two nozzles in the intake port to disable it. If the gas is mixed, the functionality of the oilers is no longer an issue.

And yes I know I can buy one with a good engine for less than it will take to fix this one.

The whole purpose of this endeavor is to get my seven year old son's feet wet with fixin' stuff. "Fixin' Stuff'" is an important life lesson that my father taught me, and I am glad he did!

Skipper · « **Reply #1 on:** Jan 18, 2009, 06:26 PM »

And where is a good place to buy parts, like gasket sets ans oversize pistons and rings?

BOOBSS · « **Reply #2 on:** Jan 18, 2009, 08:48 PM »

Hey Skipper I had an old ski doo citation that the oil pump kept loosning up on me I didnt like it either. Pluged the lines cut the cable to the pump mixed my gas. Sold it 4 years later still running. the company I use to buy engine kits and such is Pats SMall Engine Plus just google it frgot the web adress good luck. Looks worth rebuilding from the pics

CMMahy · « **Reply #3 on:** Jan 19, 2009, 10:21 AM »

I bought all my engine parts from Kimpex, including gasket sets and Piston kits. Despite them being an aftermarket company, I've always had good luck with their pistons, contrary to what some people say. They sell them for just about any sled, in most common oversizes. Most power sports shops can order from their catalogue. When you overbore the cylinders, the best way is to have the machine shop bore them out until they're cleaned up, but hold the final hone until you've ordered the pistons so they can double check the tolerances. Adds another step, but it's the best way to ensure you're getting a good fit. One thing to keep in mind, if the cylinders or crank are too badly damaged, there are plenty of shops that specialize in rebuilding cranks and re-sleeving or lining cylinders. You send your old parts in and they send you a refurbished unit, a lot of times with a warranty. I've found the prices to be really reasonable and most have a big stock, so turnaround is pretty quick. If your machine shop hasn't done a lot of two stroke cranks it can turn into a horror show pretty quickly. Good luck, and post some pictures when you get it running!

jimmygunns · « **Reply #4 on:** Jan 19, 2009, 04:46 PM »

Quote from: Skipper on Jan 18, 2009, 10:32 AM

And yes I know I can buy one with a good engine for less than it will take to fix this one. The whole purpose of this endeavor is to get my seven year old son's feet wet with fixin' stuff. "Fixin' Stuff'" is an important life lesson that my father taught me, and I am glad he did!

Great idea on this one, & I wish more people still did this type of stuff. Will this be a summer project? Good luck with it!

Skipper · « **Reply #5 on:** Jan 19, 2009, 04:57 PM »

We will see, it may be done to break in before the snow is gone. The rest of the sled is solid, so when I get the engine back together I am on the trail.

We have plenty of winter left in these parts.

If I dont get it together, I will pick the chassis apart with a fine tooth comb over the summer and put it back to 100%. I hate break downs when I am fishing.

MrMarty51 · « **Reply #6 on:** Jan 19, 2009, 07:16 PM »

That looks like a fun and worthwhile project.Keep us posted on the rebuild.
I had an older dirtbike with oil injection and the injector cost Me an engine so I disabled the injector pump and went ot manual mix.never lost another engine.
The bore to clean as mentioned in a previous post is the best way as sometimes You will order a piston and then find out it wo`nt clean up at the size You have.

Skipper · « **Reply #7 on:** Jan 19, 2009, 07:25 PM »

Weisco makes 3 sizes of pistons for that engine, clear up to 1.5mm oversize! That is the difference between a 488cc and a 509cc! I bet I can clean it up with minimal boring, and keep those cylender walls nice and thick.

Bore to clean, hopefully it wont take too much.

Oil injection may go in the reject bin me thinks! Thanks guys!

brokenline · « **Reply #8 on:** Jan 20, 2009, 06:49 PM »

i would take it that old of a sled.. after getting it fixed up id hate to see it fail becaue of that!!!

littlesturgeonguy · « **Reply #9 on:** Jan 20, 2009, 07:54 PM »

skipper, i have bought parts from these places in the past and was happy with both places.
http://www.parts-unlimited.com/
http://www.denniskirk.com/jsp/common/Frontpage.jsp

MrMarty51 · « **Reply #10 on:** Feb 27, 2009, 01:59 AM »

Just had to do a bump on this thread to see ho skipper is a doing on His project.
Here`s a couple of pics of My Harley 1957 125 cc hummer engine in the rebuild stage.sent it off to texas to Mutt.He does some real nice work.
piston is fitted.

Almost together.He replated the carb and installed a kit in it.

Skipper · « **Reply #11 on:** Feb 27, 2009, 07:40 PM »

It still sits out there in the garage. $:-\$

There is an outfit out off Spicer MN that specializes in snowmobile machine work called Echoff's. They will be doing the machine work once I get it over to them.

Everyone who knows that engine is telling me to leave the oil injection hooked up, they say it is a good reliable system.

Lobes · « **Reply #12 on:** Feb 28, 2009, 09:30 AM »

That's a really good project you have going there Skipper! I think if you rebuilt that engine back (close to) to original spec's it will last you a long time. Unless they had known problems with the oil injection system I'd leave it intact. Sounds like your main objective is to have a real good sled for fishing more than anything else.

NBG

Skipper · « **Reply #13 on:** Feb 28, 2009, 02:59 PM »

You hit it right on the head, it will be THE ice fishing machine.

My dad is a welder and machinist and he is going to engineer an auger holder that will attach to the main front suspendion bulkhead and hold the auger across the hood. I am sick of getting stuck with my ATV, and I don't want to start modifying a brand new sled for ice fishing. It will also have a rear rack to hold some gear and a 10lb propane cylinder too.

2 up is nice for fishing, and so is the studded track.

I will post as this progresses. I hope to have an "ice fishing machine" instead of a snowmobile by next fall.

michianafisherman · « **Reply #14 on:** May 18, 2009, 07:20 AM »

Looking at the pics of the fried engine, be sure the rod isn't twisted or stretched. I had this happen once in a racing engine. I rebuilt everything except a new rod. Put it back together and it ran ok, but I noticed that the piston didn't come to the top like it use to. It didn't take long for the rod to fail and I had to rebuild everything, again. From the looks of your original post pics I would say you need a whole new crank and bearings. and don't forget to have new crank seals put in also. If your cylinder looks decent you can bore it oversize and don't be afraid of going to big, if you are only going to use it for fishing, but don't go to big for trail riding or you risk the chance of overheating because they will have to remove too much metal in the boring process. Let us all know how it turns out.

Skipper · « **Reply #15 on:** May 18, 2009, 10:15 PM »

The crank and bearings are fine, I had them checked. It is all as smooth as silk and straight as an arrow.

I did get the cylinder block back from Eckhoff's a few weeks ago. She is bored over .20 and good as new. The amount of metal removed was minimal, and that makes me feel good. The bore job was elective, I could have probably gotten by with a heavy hone job. I hate go down the "aww, good enough" road, so I spent the extra money to make it RIGHT.

I will post some pics as this thing goes together. I don't have enough time to mess with it for a few more weeks, but I promise updates.

If anyone needs cylinder work, check these guys out. http://www.snowmobilecylinders.com/ Just drop your stuff in the mail and they will get it back to you in no time. I spoke with Ryan Eckhoff on the phone, he was super friendly and answered all of my questions. He even answered some questions I didn't know to ask!

They seem to be a top notch outfit.

MrMarty51 · « **Reply #16 on:** May 24, 2009, 10:45 AM »

Before You put the cylinder on be sure to wash out the cylinder with detergent and HOT water to pull all the grindings out of the pores then blow dry and oil it up real good to prevent rust.

Skipper · « **Reply #17 on:** May 24, 2009, 05:49 PM »

That is the first thing that Echoff's told me!

They told me to wash it GOOD in HOT SOAPY water TWICE and rinse it with a strong stream of cold water. He also recommended the same for the crank case because of the flack in there.

He told me something else, something that I thought was untrue. He said not to use synthetic oil until the engine was broken in. I thought this was an old wife's tale, but he is the pro and I am not. I think I will do it his way with the cheap 2 cycle oil. He also told me to mix my first tankful at 40-1, he said this is a smart thing to do with a new engine. It may smoke like an old freight train and foul plugs through that first tank, but at least the engine will be safe.

he also recommended the proper sealants for the crank.

Skipper · « **Reply #18 on:** Jun 24, 2009, 08:07 PM »

I will get the gaskets ordered as soon as I get home from vacation next week and put her together. It just seems strange to work on a sled in July.

brokenline · « **Reply #19 on:** Jul 06, 2009, 11:43 AM »

hey its only 5 months off!

Skipper · « **Reply #20 on:** Jul 06, 2009, 11:52 AM »

I just got home from Texas so I better get those gaskets ordered.

Skipper · « **Reply #21 on:** Aug 05, 2009, 05:40 PM »

OK, I got.....

Complete gasket set with crank seals.
.20 oversized pistons and rings
Jugs bored .20 over
Piston pins and piston pin bearrings
high strength loctite thread locker
Anaerobic non shimming gasket compound
Cheap 2 stroke oil for assembly and break in
BR9ES NGK spark plugs.

OOPS! I forgot new head bolts!!! This is where the fun begins! Because Polaris assembles the cylinders with high strength thread lock, I needed to heat the head studs to remove them from the block. Normally this is not necessary, but the machine shop needed all hardware removed so they could bore the cylinders out. I am not an idiot, so I would never reuse a stud that was heated with an acetylene torch. I thought the parts store would have them, Nope. I thought the small engine shop would have them, nope. The Machine shop could get them from Polaris, but said I could save some money and get them myself. The local Polaris dealer is #5 on my black list because of poor service and an awful attitude, so I hit the net. The cheapest I could find this little bugger OEM was $4.58 a piece! I need 14 of them...$64.12. HOLY CRAP! I got my card out and began to place my order; I stopped when I saw the shipping charge, $16.75 extra!

$80.87 is a little to steep of a price for a box of these dumb bolts.

I stopped the transaction, got a calipers and thread gauge from my tools, logged onto McMaster-Carr's website, and found them for cheap. I also got a bag of 100 nuts for less than Polaris was going to charge me for 5 of them. Hey Polaris dealer.....

Shame on you for parts gouging! These studs from Carr are a better grade too!

When I removed the studs, I pulled the threads out on one hole. I asked my brother (a GM dealer mechanic) to take it to work and install a thread repair coil. I got it back with an ultra high strength titanium insert. 8)

When the UPS man delivers my studs, I will begin to put the old girl back together. Until then, I will be cleaning the garage and putting all of my tools away.

holehawg · « **Reply #22 on:** Aug 05, 2009, 07:01 PM »

okay skipper;;;i have a high opinion of you....should i close the deal on a 2009 polaris 4000 awd atv

?

Skipper · « **Reply #23 on:** Aug 05, 2009, 08:27 PM »

A what? A sportsman 400?

I don't know much about ATVs. I have a 06 Polaris Sportsman 500 that I bought new in 07 as a carry over. If I have any advice, it would to be to look for a carry over. I got a brand new machine with a warranty for $1500 less than a brand new one on the sales floor. You may not get to pick the color, but you will save a ton of money.

My sportsman has been a great machine. It will go through anything and it rides smooth as can be. The guys that sold it to me are apex jerk hunyuks and I will never set foot in their dealership again, but the machine has been great.

Skipper · « **Reply #24 on:** Aug 06, 2009, 07:00 PM »

My headbolts and nuts showed up from McMaster-Carr in less than 24 hours!

I only selected UPS Ground service for delivery, so they must have fired those parts out with a rocket. I have only ordered from this company one other time, and the delivery was just as fast.

A+

holehawg · « **Reply #25 on:** Aug 07, 2009, 12:49 PM »

sorry skipper i was suffring from ADD when i wrote that...

...what i meant was.... have ya ever heard any bad on the 2009 polaris 400 sportsmans

? looking at a new one ...their 4 wheel drive ..but ya dont have to shift...i've heard if ya dont service them the drive belt goes sprung...and messes up the drive train costing much $$$$$$$$$$$$$$$$

Skipper · « **Reply #26 on:** Aug 07, 2009, 05:32 PM »

I do not know a thing about the 400, other than it is a sized down 500... I think?

People have a total problem with the whole idea of the Polaris transmission system. It works great! Polaris had some trouble in the early 90's with water getting into the case, but it seems to be resolved. My boss has 3 500s, 2 have over 10,000 miles on the odometer and have had no more than minor usual problems. Most of the people that have problems with the Polaris transmission run them in high range all the time and burn the belt. You don't pull stumps out or go swamping with a Polaris in high range any more than you would shift a Honda wheeler into 4th gear at a dead stop and try to pull something. Use low range and you will be fine!

Shifting sucks. I love my PVT because it is always pulling hard. When you hit a slush pocket out on the lake, you can on it and she goes. You don't need to worry about fumbling with gears, it is always in the proper rpm range.

It has no engine braking at all, when you release the throttle she is free wheeling. I don't like that at all.

Sven936 · « **Reply #27 on:** Aug 07, 2009, 05:40 PM »

My headbolts and nuts showed up from McMaster-Carr in less than 24 hours!

I love McMaster Carr. They have just about anything a guy needs and deliuvery right to your door.

holehawg · « **Reply #28 on:** Aug 07, 2009, 06:11 PM »

thanks skipper....that's what was bugging me about the belt rumors / all wheel drive / auto mantic shift thing... i guess if i just don't treat it like it owes me money it'll be a good buy....just Leary about the newness of this concept...and i wanna make sure i buy a half way decent machine......

Skipper · « **Reply #29 on:** Aug 07, 2009, 08:37 PM »

It is not a new concept, the PVT goes back to 1985.

It is the same concept as a snowmobile, with a drive and driven clutch. The technology is at least 50 years old.

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Author Topic: Old Oil Polaris Rebuild (Read 13615 times)