Q: I have a 2007 Polaris 600 H.O. Switchback that I re-jetted for the elevation in the Black Hills of South Dakota. While we were in the Black Hills at the end of March it snowed over 30 inches in a day and a half. My sled ran good the first two days but after we got all the snow it would keep stalling out on me almost like it was running out of gas. I thought maybe it was starving for air because of the deep snow. But even when I would stop and clean out the hood vents and air intake filters it would run rough and with little power. All of this happened on our last day, so I loaded it on the trailer and left it alone. When we got back home I started it up after sitting for a couple of days and it seemed to run OK. I plan on going back out to the Black Hills next year, so if you have ideas of what to look for or change let me know.
Todd LaBarge, Reinbeck Iowa
A: This is likely a case of snowdust ingestion into the air intake system of the sled. IQs have a potential to draw in snow around the headlight and through the headlight adjustment knob that’s in front of the gauge. First, confirm that the gaskets around the headlight are in tact. In some cases, the snow sits under the headlight and eventually the wind pushes the snow through the gasket and into the intake. If the gaskets are damaged, replace them. If they are OK, a piece of duct tape around the headlight and over the headlight adjuster is a quick fix for riding in deep powder. A second issue could be in the airbox, which might not have been properly seated after re-jetting the carburetors, allowing snow to get sucked into the engine. Use a flashlight and mirror to carefully check that the boots, seams and connections of the airbox are sealed. Another possibility could be water in the fuel from condensation, which can usually be corrected with a dose of isopropyl alcohol that absorbs the moisture.
Q: I own a 2003 Arctic Cat F7 Firecat. I bought it used in 2005 with 2,600 miles on it. The chain-side drive axle bearing was junk and the case was chewed up. I replaced the jackshaft and the drive axle bearings (both sides), chain (but not the gears), drive axle and the chaincase – all brand new from Arctic Cat, including the oil. In January 2009 (2,600 miles later) the same bearing is junk again. I was told this is a problem with this machine. I have also been told the oil should be changed periodically and that maybe a magnetic dipstick [in the chaincase] might help.
A: The ’03 Firecat has a unique bearing configuration on the chaincase side: the bearings have an integrated groove, which houses an o-ring. This is a two-piece bearing design that, arguably, doesn’t last as long as a single-bearing setup. Fortunately, you can retrofit to a bearing that has a seal on the outside, which Arctic Cat used for many years with good reliability. The bearing we recommend is Arctic Cat part no. 1602-051; the seal is part no. 0107-003. You might also want to install greaseable bearings on the other end of the shafts. Also, fresh chaincase fluid certainly improves the longevity of driveshaft and jackshaft bearings. The service interval for chaincase fluid is every season or 1,500 miles. A magnetic dipstick won’t necessarily prevent chaincase failure, but it will extend oil life by holding the tiny metal filings that are shed by the chain and sprockets.
Q: I spend 95 percent of the time riding on flat ground, but I got an insane deal on a mint, 2006 Ski-Doo Summit 600 H.O. SDI. Thinking hybrid Renegade, I put a 144- by 15- by 1.25-inch Rip Saw track on it along with stock [clutch] pins and spring for use at low elevation. The first time I took it out it over-revved, and in deep powder it spun worse than a 121-inch track. After that I changed the top gear from 19 to 21 teeth. That helped and brought the [peak] rpm down to 8200 with the TRA’s set on 1. Do you have any better ideas for clutching?
Grand Forks, North Dakota
A: It sounds like you are close in your set up, as 8200 rpm is within the engine’s peak horsepower range. Starting with the TRAs on setting no. 1 is the correct choice, as long as the sled doesn’t bog out of the hole due to a low clutch engagement rpm. Many clutching gurus believe that lower TRA settings bring better performance with complete shift-out and a strong squeeze on the belt. Your 21-tooth top-gear selection is what we recommend for your needs, as long as it’s paired with the 43-tooth bottom gear that was standard for a 2006 Renegade 600. Summits came with a 45-tooth bottom gear, so check the bottom sprocket to make sure your sled’s drive ratio is appropriate for trail riding. As for the spinning of the track, it does not make any sense that a 144-inch track spins more than a 121-inch track in powder. Perhaps the screaming engine just made it seem like the track was slipping.