Hi guys,

I bought an '06 Rhino 660 last year. Cosmetically it's in great shape, it didn't have a digital display on it when I bought it, so no idea the amount of actual miles.

Starts easy, reliable, etc etc.

I've put 400 miles on it in 9 months. It uses oil.....about 1 quart in a heavy day of trail riding (80 miles).

Oil used is Rotella 15-40

Exhaust isn't blue smoke...it doesn't leak, it just burns it I guess?

I've owned a few Yamahas and have never experience this kind of usage.

Is the engine on it's way out?

I'd switch back to the 10W-40 Yamaha recommends and see if it improves. It might not like the heavy diesel oil.

had a 660......never burned oil........

now have a 700.......change oil ever 40 hrs or so.......

never uses a drop.....use K&N 204 filter.......

this filter makes it easy to change.....having a full cage roll bar..

bed does not tip......my oil is Rotella T6 '5w40' full syn.....JASO wet clutch rated

http://rotella.shell.com/products/t6-full-synthetic.html

If it isn't leaking, it has to be burning it. Possibly it only blows blue smoke while under heavy load and you're too busy driving to see it. Here's a rundown on what all it could be. There are lots of possibilities. This article is about cars but much of it applies to any 4 stroke engine.
BURNING OIL

Thanks for the replies....It's not the oil. It's JASO certified and I have 10s of thousands of miles on wet clutches with the same oil.

It's a simple engine. I'm afraid the answer will be simple enough.

I'll start troubleshooting, starting with a compression test and maybe an oil analysis.

It's got to be valves or rings.

What does the spark plug look like?

couldn't resist...............

I'll pull it tonight and see if I can locate my compression kit.

It's in a cardboard box somewhere in the garage.

A friend of mine had a Rhino that used oil. According to what he told me, and what the Yamaha dealer told him, the engine got too hot because of insufficient engine cooling, and the rings failed. This led to the oil burning problem he experienced. He had it fixed and sold it.

I would think with it using that much oil, that plug has to be nasty.

Pulled the plug, it is not as bad as I thought it would be. Some carbon fouling but not much.

Compression is 105-110. Trying to find factory specs on compression and find a lot of conflicting numbers. Some sources say 180 psi others 120.

Cleaned the air filter and changed the oil and filter and went for a 28 mile ride this morning. Burned about a half quart.

It seems to burn more at high RPMs as this morning's ride averaged 18 mph.

Burning that amount of oil can't be right, but for now I'll just keep the dipstick wet and keep banging around the hills.

Are you sure it's burning and not going somewhere else? Burning a half a quart in 28 miles is crazy oil consumption if in fact that is what's happening. Check your exhaust pipe and see if it has an oily smell to it.

I sure bought a turd.

100% sure it's burning the oil. It is in it's death throws.

Since my last post, I've been dinking around with it with the hopes that superficial tinkering would fix a large mechanical issue.

The engine is machining fine sparklies into the oil. It now belches blue smoke at start up, at idle and especially on acceleration.

As mentioned above, I changed the oil and within an hour of run time, the oil is black and smells burned. So I think this is due to the clutches failing? It won't go over 28 mph now and that is definitely less than a few rides ago.

I took it to an independent shop and they confirmed that both engine and trans will need a complete rebuild....ballpark of $3200.

So I took it to trade it in on a new Pioneer 500, those are some cool little machines. Dealer sniffed out the problems in about 2 seconds. He doesn't want it.

It's going on the auction block AS-IS. Nobody buy a camo Rhino at auction in CO this month OK?

I like to think I'm not a mechanical retard and have avoided buying lemons so far in my 45 years of life.....When we test drove it, it drove fine, no smoke, no flags at all, and the price was TOO GOOD TO BE TRUE! I put maybe 40 over-maintained hours on it in the last year and it sure went to crap in a hurry.

In perspective, if this is the worst thing in my life, then life is grand!

That sucks, sorry to hear it. Some of what you described sounds like your wet clutch has gone, I've had to change mine (700 Rhino) twice in the past 3 years and it was doing just what you described speed wise plus it had no torque at all. The shoes in the wet clutch get into the oil when they start to come apart, maybe some of that got into your engine and caused it to go.