Arctic Cat Sno Pro - Finished

I have been working on this Arctic Cat Sno Pro 600 on and off for a while now.  Today I was finally able to wrap up the project.  I will give you a quick recap of the situation.  The machine quite running last spring, the owners then left it sitting on the beach where it stopped.  After a whole summer of being very close to the salty ocean they brought it to me.  I figured out that the initial problem was a faulty fuel pump.  After changing the very expensive ($447!) fuel pump I started to fix all the rusted and corroded parts.

The worst corrosion was on the brake system.  The brake is made from aluminium and steel, that is a bad combination in a salt water environment.  When I first pulled the machine in the shop the brake was locked up solid.  After a liberal soaking in Deep Creep penetrating oil and a lot of pounding I was able to get it to turn by hand.  I thought that it would loosen up with use, but when I test drove the machine it was dragging and heating up the rotor.

After a lot more oil and pounding I was finally able to remove the rotor.  Once I had the rotor removed I put the caliper back together and used the brake pressure to push the pistons out of the calipers. The top photo shows the back half of the disassembled caliper in place on the machine.  The caliper is actually part of the same casting that holds the bearing for the drive shaft.  The rotor goes on the end of hollow splined shaft.

This second photo shows the other half of the caliper, the piston, and the seal.  Despite being made of stainless steel the pistons were corroded and pitted where they were in contact with the aluminum caliper.  This corrosion caused them to bind or stick in the caliper and prevent the brake from releasing.  At first I thought they may need to be replaced, but I was able to clean them with fine sand paper.  I reassembled everything with a little bit of silicone grease on the parts and  the brake now works fine.

Arctic Cat SnoPro - Update

I have replaced the fuel pump on this machine and took care of a few minor corrosion related issues.  Everything is running fine except the brake.  When I first put this machine in the shop the brake was locked up tight.  I took the outer half of the caliper off and cleaned things up.  It seems to turn free, but when I test run the machine it quickly heats up and seems to grab like crazy.  I drove it up and down the beach for two minutes and the rotor was glowing red!

I'm not sure what the problem is, but I guess I'll have to take it apart and inspect everything?

Arctic Cat F6 Sno Pro

Today I worked on a 2010 Arctic Cat F6 Sno Pro.  The owner brought me the machine because it would not start.  He suspected a fuel problem (normally I don't listen to what the owner says, but this time he got it right).  I pulled the rope a few times and the engine did not fire.  I pulled the spark plugs and checked for spark, then squirted a little fuel in the cylinders.  This time when I pulled the rope it fired up for a couple of seconds.  Definitely a fuel problem.

This machine has a modern engine with a battery less fuel injection system.  When you pull the rope the stator makes enough electricity to charge a capacitor and run the injection system.  I pulled the fuel line off the injector rack and checked for fuel pressure when pulling the engine over.  There was no fuel pressure so I decided to check the voltage to the fuel pump.  I found the wires going to the pump and checked for voltage when cranking.  I saw spike of 15 volts when pulling hard on the rope and it then gradually dropped off.   All these signs point to a bad fuel pump.

The pump is mounted inside the tank very much like a typical automotive system.  Just like working on cars, it is a pain to get to the pump.  I decide that I would like to do one more test to make sure it was the pump before I pulled everything apart.  In the photo you can see my temporary fuel system that I rigged up to run the engine.  I have a "Hudson" type garden sprayer filled with gas, I pumped this up to 15 psi (thanks Dave for the help) and connected it to the fuel rail using a few plumbing fittings and tubing.  With this setup supplying the fuel pressure the engine ran OK.  I later learned that the system is supposed to run at 40 psi, but 15 was enough for testing in the shop. 

Once I was sure that it was a bad pump I pulled everything apart and took the pump out of the tank.  Now I just need to find a replacement.  The Arctic Cat dealer only sells the complete pump assembly with the mounting bracket and fuel level sensor attachment for $450!  The pump itself is a basic Walbro like automobiles have, normal price $80 -$100.  Hopefully I can find a source that will sell me just the pump.  Any one have any ideas where to look?

C.O.