Thoughts on 04 Classic 800? - Snowmobile Forum: Your #1 Snowmobile Forum

meburdick · 11-13-2012, 10:15 AM

I know that the 800 Liberty motors had issues in years prior, but I'm wondering about the overall list of potential issues with a 2004 Classic 800.

BC_Dan? Thoughts?

**RJ Gleason** · 11-13-2012, 10:24 AM

Most issues with the 800 was in mtn sleds where they tend to stay at high rpm for long periods.
In the trail sleds, not so much.

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**BC_Dan** · 11-13-2012, 10:25 AM

Case support in any Polaris big block 800 is suspect. It's more of a problem in the long track mountain sleds than the trail sleds. Adding the wide bearing kit and keeping the clutch balanced seem to be two things that help the most at keeping the engine from failing. I would also add an engine plate.

Sometimes having total crank runout checked can identify a case/crank that is about to fail. A crank that is way out almost always fails. A crank that is in spec isn't guaranteed to stay running, but it's still nice to know.

Make sure the VES guillotines aren't the aluminum ones, they have a tendency to fail at a much greater rate. Some have been replaced with Stainless Steel. The VES billows should be replaced if it's the old kind. The new ones are orange. Check the springs while you're in there, too.

Other than general maintenance, the rest of the sled shouldn't have any glaring issues.

Good luck in your choice!

meburdick · 11-13-2012, 10:45 AM

Thanks, guys. I'm looking at one mostly as a possible "investment"... The asking price seems low, so I'm wondering if there are issues to look for or if it might be worth trying to resell it for a small profit (a few hundred dollars) at all. While the sled is nice (M-10, Edge chassis, reverse, electric start), I personally don't think I would want to ride anything bigger than a 700. In reality, my ideal sled would be a 600 Edge for the next season or two, but the 500 that I have will certainly do.

**BC_Dan** · 11-13-2012, 12:30 PM

There's not much weight difference between an 800 and a 700, and as long as you don't hit the "go" button too hard, you won't feel much difference between the two. The 800 is a torquey engine (is that a word??) and makes a sled a lot of fun to ride. It's still a popular engine out west, even with it's issues. I would probably still be riding one had I not burned all my sleds up a few years ago..

white lightning · 11-13-2012, 03:39 PM

BC - correct me if Im wrong .. crank issues on the 800, especially in 2004, I thought polaris pretty much have it updated at that year. 2002 version 800s, even though was the most powerful .. they were prune to alot of failures between the crank issues, excessive viberations (clutching out of balanced) and VES (due to high heat) breaking and dropping into the cylinders, causing havoc to the engines. The following year in '03 .. polaris had them engines detuned for that specific reasons. My understanding was .. in 2004, Polaris did some updates for waranty purpose. WL

**BC_Dan** · 11-13-2012, 06:29 PM

The last two 800's that I was around that broke were both 05's. I think (as do others a lot smarter than me

) it's a case problem. Polaris cases are very porous, which leads to the case getting wallowed out by the bearing, especially on a long track sled. When the case gets out of spec enough, the crank fails. The wide bearing helps spread out the force over a greater area in the crank and gives a bit longer life to the case.

Polaris VES valves in the 800 were aluminum until 2004. They tried titanium as an option but didn't work well. 2005 they made 'em out of stainless steel and that solved that problem. It's an issue on the 800 VES engines because there is NO cooling around the VES valve on the 800 cylinder. Heat kills the aluminum big time. The 700, which has the same block, but smaller cylinders, had hardly any VES failures. The cooling jacket cools that part of the cylinder, so there isn't an issue.

A big problem in the 2002 is also midrange lean conditions. There were a lot of failures on sleds that were just putzing down the trail because the needle was too lean, seizing the engine. Polaris had a huge main jet in those to try to keep the thing cooler. The 03 needle change helped that issue. The 03 main jet is a LOT smaller than the 02, which gives the benefit of better gas mileage. 03 also got a lot of different electronics, that's when PERC came out.

I don't think Polaris ever did get the 800 right, no matter the year. With a little work, they can be set up to work well, and with a LOT of work and money, you can make them bulletproof. Google Indy Dan and Torque Master to see how it should have been done

meburdick · 11-13-2012, 07:43 PM

The guy claims about 1600 miles on it, wants about half of book value. I'm thinking that it is a gamble - even at half of book value - because I could quickly uncover issues with the power valves or the motor in general. He's had it for sale for quite a while and hasn't moved it... I'm suspect of it being truly worth taking a risk on buying then re-selling for a profit.

**BC_Dan** · 11-13-2012, 11:06 PM

I hear you. The 800 is totally a gamble. Some run awesome. Well, they all run awesome, but some break early

white lightning · 11-14-2012, 08:05 AM

I hear ya BC .. its funny how I always stay away from anything new that Polaris ever comes out with in its first year. Like the STORM 750 back in '93 .. like the '05 Fusion 700s and 900s. There were a few (maybe more) that Polaris ever did their homework right .. '97 - '98 RMK / XC7, '99 - '03 XCR800 and to name a few. WL

meburdick · 11-14-2012, 08:12 AM

What might I expect to pay for a pair of 05 valves to get the stainless steel version? Used is fine, and I could state that the motor was upgraded to prevent a problem.

**BC_Dan** · 11-14-2012, 08:35 AM

The guillotines are over 100 bucks new, you may be able to find used steel ones at a salvage yard. Make sure they have not been replaced. The aluminum ones will be smooth both sides, the steel ones are hollowed out on one side to reduce weight.

meburdick · 11-14-2012, 08:37 AM

Thanks, BCD. Good info, as always.

I'll start looking around for parts now, and will check to see if the valves from a 500/600/700 would work on the 800 as well. I'm guessing the valves are the same, but the springs are different.

CORRECTION: Valves are definitely different. This will make it a little harder...