Friday March 15th, 2013

Greetings and welcome!

Yesterday wasn’t good. Late afternoon the day peaked at 42, and it was a sunny day. There was definitely some melting going on. The usual sunny spots that burn down first around High Falls Flowage were fine as of 4pm when I went by, and the trails looked great other than a few slushy spots.

I expect that the sun and warmth will make some icy spots when the melt water and slushy spots freeze back up. I also saw some standing water in a low spot, and would guess that it isn’t the only place that it is happening. For the most part our ice base saved the day and the trails will be fine.

I have to tell you.. to have conditions like this on March 15th is almost as crazy as last year’s 80 degree weather. There is very little sunburn and a great base. I can only tell you what I saw around Caldron Falls and High Falls Flowages yesterday, but we are doing good, especially for this time of year. I wasn’t sure about riding on the weekend of the 9th, and here it is the 16th & 17th with great trails*. Color me surprised. (*Other than plowed roads, which are mostly bare.)

Looking at the GFS, I am seeing nothing but winter. There are a couple of snow storms, followed by more cold air from the north. It looks like today’s high of 31 will be the warmest between now and the end of the month, at least on the 850mb temperature maps. As we saw yesterday a sunny March day can change that to 41, and there are bound to be some.

Right now the NWS, the NAM and the GFS forecast models agree on pushing Friday’s storm south of us, bringing us about an inch or an inch and a half. The TV is showing 2.6 for Lakewood, more along the lines of yesterday’s expected storm path. Either way it should be at least a little new snow to add some free snow to the hard packed trails.

My tech pages bring a lot of e-mail from people that ask me snowmobile repair questions, and I am always glad to help. I have a FB friend that had a pretty similar problem with bad gas to what this guy saw, so I will share my response. It is somewhat detailed, so if you don’t care about bad gas and piston failures (yet) and want to skip ahead, I will put a dotted line at the bottom.

This is an edit of his e-mail and my response.

I just recently detonated two pistons on my 08 700 dragon and my son also (within 5 min of each other) stuck a piston in his 03 Pro-X. The D7 PTO side piston was in the process of losing the ring landing. Lots of Alum deposit on the plug. The MAG side was also showing wear but wasn’t heating up as much as the PTO side as there was still a fair amount of oil residue.  My Son’s Pro-X was a different story, His PTO side melted a passage right through the ring split and also created a 4 corner stick pattern. He too had a fair amount of oil residue on the MAG side. Up to this point both sleds have ran great without issue.

Sorry to hear that you guys burned down. After reading your e-mail I have
no question that you got some bad gas. First of all, three out of three
sleds had problems less than 9 miles after refueling. That is pretty much

Piston failures are usually pretty easy to read. Damage to the center of
the piston is detonation. That can be caused by either low octane gas or
advanced ignition timing.

If the exhaust port side of the piston melts off, it is running lean. The
two look very different.

My call from your description is that you got some old gas and it caused
detonation, burning the tops of the piston.

Your son's 4 corners failure is a classic.  The scoring takes place in
this pattern because those areas of the piston around the pin where the
casting is the thickest. When the piston is seriously overheated ( like as
it is melting from detonation), the thickest areas will expand and distort
the most.  Usually it is on either side of the pin, giving it a
symmetrical 4 way appearance.

As far as your son's octane question.. The octane rating on the pump is a
measure of how evenly it burns, and specifically how much compression that
it can stand before it self-ignites. Stale gas with a reduced octane will
still burn, but it will start the burn while the piston is still on the
way up on the compression stroke. That puts extreme heat and pressure on
the piston crown, eventually melting it.

Octane -is- also a family of hydrocarbons that are a component of gas, but
the research octane rating is about how much compression it will take
before detonation.

Personally I'd take a series of fuel samples and go back to the gas
station. You can get the octane rating tested, but it isn't cheap and you
need to be prompt about it. The best way around that is possibly a local
school that offers automotive engineering classes. They might have the
ability to test it. Most states have something like a bureau of weights
and measures that will test real octane ratings against the pump sticker.

I have seen people have problems from using ethanol free 91 or 92 octane
premium. Like you and I, they want to use the best fuel possible in our
high performance power equipment, so we run it. Unfortunately, sometimes
the high grade stuff doesn't sell fast, and it gets stale.

I currently have a remote friend that also had a four corners failure. A
guy that I wrench with and I both noticed reduced performance on our sleds
after using a local station's no E 92 premium. We switched brands/stations
and it was very noticeable. Thankfully we didn't burn down, but it is

One last thing to talk about when we discuss bad gas is water in the gas.
People that run ethanol WILL have some level of water in the gas. If it is
bad enough, the water displaces the film of oil on the piston, and you get
what looks like a lubrication failure, usually on the intake side. This
page shows it pretty well.

There isn't really a good way to tell if you are getting bad gas at the
gas station other than your nose. A friend suggested squirting in a blast
and stopping and sniffing the nozzle. You know what good gas smells like.
If there isn't much smell or it is stinky, hang up the pump, pay the
quarter and go somewhere else.

Ethanol is easier to test for. You can get a kit something like this..

 or for faster results..

Personally I won't run the stuff if I can get around it.

It sounds like you had some bad gas Rich, and it is pretty clear cut by
your description of the piston failures. Best wishes with your rebuilds
and tell your friends about the gas so that they don't burn down too.


The last few weeks have been work work work (sorry to cuss like that..), so I haven’t gotten in a lot of trail time, especially in the daytime where I would venture farther. It has also brought little shop time. Hopefully that will change over the weekend.

I did get a little time with the new RXL, and found it to be in really nice shape. It needs a few minor things, but the biggest things holding up a ride is a tank of gas, some carbides, and a sticker.  I am really looking forward to riding that.

RXL #2 is still down with what looks like a cracked piston skirt. It isn’t that hard of a fix, but at this time of year I’d rather spend my free time riding the ones that run. I can work on that after the snow goes away and take my time on it.

For now the Indy Trail is it, but I am hoping my carbides for the RXL come tomorrow.

I will encourage you to look at yesterday’s comments. Packerland Rider posted a really comprehensive report on his ride, and Jim had a great ride between here and Goodman. Thank you for sharing you guys, you help a lot of people!

Klings asked how the Caldron Falls Flowage is up this way, and I don’t know. I haven’t been there in a while. The best that I can tell you is that the ice fishermen that removed shanties from the flowages this week didn’t have a lot of problems. Other than yesterday’s 42 and sunny there hasn’t been much melting.

As far as will I be out and about Saturday at a local trail stop since the Rapids is closed, I would like to be. I have a few things to tackle in the morning that really need to get done.  I haven’t really figured it out after that. Curve Inn is a good possibility.

That is about it for me. Have a good weekend and thank you for visiting!