I"ve owned ten Polaris sleds between 1993 and 2004 and the only polaris I would buy today would be a carbed 600. My 04 was an 800, and i currently ride a 660 buillt by Iantomasi T&T. The 440/600 motor has much better transfer ports than the big block motors, a tougher crank/rod assembly and gear driven water/oil pumps. It spools up faster and is capable of making more power. Well, most of you know this already. So why is the small block 800 so problematic?? I think the answer lies in where polaris is putting the fuel into their motor. When they used the 4 injector system, the motor wouldn't respond at the transition point....transitioning from well atomised fuel to poorly atomised fuel delivered by the injectors closest to the cylinder. As we know with carburation, a crankcase full of non vaporized fuel makes for a very hard to tune engine. And maybe one reason why Cat has resisted transfer/boost port injection. Unburned fuel in the combustion chamber causes a whole nother host of problems...Although placing the injectors closer to the cylinder may lead a polaris engineer to believe he is gaining control over fuel delivery, if fuel is not fully vaporized when it enters the cylinder, he is tuning a ghost. I won't be buying any more polariss, i don't walk around in a polaris jacket any more, and since Tiller got his $54 million, the polaris snowmobile division has been dying a slow death.
Dear Polaris Survey
- Thread starter thefullmonte
- Start date
I think that is one of many problems, but yes I do have to agree with you. The one injector is spraying directly at the cylinder and in no way taking advantage of engine vacuum to help atomize the fuel. It was definitely another one of those things that I looked at and shook my head. I am in no way a fuel injection expert, but this just didn't look right. It's like they were hoping to cool the cylinder by spraying fuel on it.
I'm curious when they spend millions on testing what they learn. Why did this design ever go into production. There is no way they didn't see these problems in the field. Far too many failures to prove otherwise. I still say for all the additional millions Polaris invested on updates and changes that they could have saved face and given people their money back.
I recently sold my dragon to a good friend and even with all the time and money invested trying to make that thing right it still failed on his first ride. Sounds like a lower end issue, but we won't get to investigate for awhile yet. These motors are just doomed to fail.
This experience has taught me something though. I can build a more dependable fun mountain sled for just a fraction of a new one. Which is what I'm going to do. Welcome back Yamaha (2 stroke). lol
