Tuesday, December 28, 2010

House Call - Boiler Cleaning

I have had a lot of calls for work on heating systems lately.  These things always come up during the worst weather or over the holidays.  Most of the jobs are pretty simple: plugged/frozen filters, wore out pumps, loose wires, etc. 

The one I worked on yesterday was a sooted up heat exchanger on an oil fired hot water boiler.  When an oil burner runs improperly (normally due to a bad nozzle) it produces soot.  The soot builds up in the heat exchanger and blocks the air flow.  As the air flow becomes restricted it causes the burner to burn worse, this causes more soot...  Eventually it gets plugged up so bad it won't run at all, that is when the home owner calls me.

To fix it you need to take the sheet metal covers off the outside of the boiler and open up the firebox.  On this boiler I had to remove the chimney to access the top of the heat exchanger .  Then you take a long wire brush and scrub the soot off the fins.  If it is really plugged up tight like this one, you may need to use a thin metal bar to make room to get the brush in.  Once you have it cleaned out you of coarse have to fix the problem that caused the soot buildup in the first place.  It is a very messy job.  This one took about 4 hours total.

Monday, December 27, 2010

Broken Fender

The wind blows a lot around here.  I don't think most people realize just how hard the wind can blow during a winter storm on the tundra.  The Yamaha Grizzly in this photo was parked in someones yard and the wind made it roll backwards across the yard.  It was moving fast enough to break the fender when it hit their cloths line pole.

The repair is pretty straight forward.  I cut a 1/16" thick piece of aluminum to fit on the backside of the fender and use pop rivets to hold it all together.  The trick to making the repairs last is to use lots of rivets and spread them out.  On this repair the rivets were inserted on the plastic side and set against the aluminum.  If you end up with a location where you have to put the rivets in from the aluminum side they will not set or expand properly against the plastic.  In this case you must put washers on the rivets or use "exploding" rivets (the kind that separate into petals when you set them.)  When done carefully the fender ends up almost as good as new.

Saturday, December 25, 2010

Tool Tip

Today I have a tool tip.  When I need to clean rust or crud from parts this is what I reach for.  This is a wire brush that is made for cleaning the inside of copper pipe fittings before soldering them.  You can find them in a few sizes in the plumbing section of any hardware store.  They have very stiff bristles that scrub well and they also fit into holes and small spaces. 

I also have a few that I have cut the handles off.  If you put them in a drill they make parts cleaning fast and easy.  The photo shows the end of an axle that I cleaned using one of these brushes.

Wednesday, December 22, 2010

Honda 420 Rancher - Update

Here is a shot of the engine all apart.  I found a cracked piston and the cylinder was a little scratched up.  I'll have to replace the piston of coarse, but the cylinder can be honed out.  I also found a few wore out shift dawgs in the transmission.  The gears and sliders are rather expensive to replace, but I can salvage those out of the other wrecked engine.  The oil drain plug threads were also stripped out.  I will have to tap them out to a bigger size. 

Tuesday, December 21, 2010

Honda 420 Rancher

My latest big project in the shop involves these two broke down Honda 420 Ranchers.  The engine in the green machine was another victim of a stripped out oil drain plug.  Normally when they get run without oil the piston fails and the cylinder gets a little scratched up.  This one wrecked everything, the piston, cylinder, crankshaft, and I think the case was even damaged when the broken rod flew around.  The red machine is a donor that I bought for parts.  It has some kind of  transmission problem.  I am hoping to to make one good machine out of the two.

The first step is too pull the engines out and take them apart.  I had some help in the shop today.  He needs a lot of supervision, but he works for cheap.

Here is the engine sitting on the work bench.  The Honda 420 is the same basic layout that Honda has had for years, single cylinder, overhead pushrod actuated valves.  It has now been upgraded with liquid cooling and a basic fuel injection system.  It also has lots of cost saving features like no recoil starter.  Like most ATVs, the engine and transmission share one common case and oil supply.

Friday, December 17, 2010

Yamaha Grizzly 550

Today's project was a Yamaha Grizzly 550 ATV that would not start.  This is a newer machine with a fuel injected engine.  When I turned the machine on it displayed an error code "33" on the instrument panel.  I looked in the service manual and saw that code 33 was for an ignition fault.

I had to remove a body panel to get at the ignition coil, and once I saw it the problem was obvious.  One of the electrical connections to the coil had corroded so bad that it fell off.  Most repair shops would probably tell the customer that they needed to buy a new coil (probably $75), but I decided to try and save this one.  

I used my Dremel tool to grind away the plastic case on the coil and exposed a non corroded portion of the connection inside.  I then soldered a wire to this spot and crimped a new tab on the end of it.  To finish it up I put the coil back on the vehicle and sealed all the connections with "Liquid Electric Tape".

The whole job took about an hour and I avoided the cost and wait of ordering a new part.


Arctic Cat TRV 1000 Cruiser

I had a 2010 Acrtic Cat TRV 1000 in the shop yesterday.  The machine had a slipping belt drive.  When I pulled the cover off the belt I found that it was covered in oil.  This was a very surprising discovery given the almost new condition of this machine.  I talked to the local dealer (in Nome) and found out that they have had a few problems with the seal behind the secondary clutch.

Removing the old seal was a bit of a trick.  If you have a seal that is easily accessible you can pry it out or drive a couple of screws into the face of it and use a claw hammer to pull it out (another trick that I learned from Dave). This seal was located deep down in a recess in the back of the clutch housing.  Being located in that narrow recess prevented any prying from the side.

This job was a great opportunity to use a tool that has been sitting in the bottom of my tool box for years.  This photo shows a seal puller that I bought at a rummage sale a long time ago.  I think that it is actually made for pulling packing glands in valves or traditional rear main seals in engines, but I figured it would work fine for this job.

I drilled two small holes in the face of the seal to twist the little "cork screw" into.  Then I simply alternated pulling on each side till it popped out.  Once I had the seal out it was a simple job to tap the new one in and clean all the oily mess off everything.


Wednesday, December 15, 2010

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?


Tuesday, December 14, 2010

Left Hand Drill Bit

The machine that I was working on today had a few stripped out screws.  Many ATVs and motorcycles have parts put together with small phillips head machine screws.  The screws are typically steel and they are threaded into an aluminum piece.  Steel and aluminum together leads to corrosion and stuck fasteners.  If the fastener is a hex head bolt it is normally not a problem, but phillips head screws strip out very easily.

The first thing I do to remove one of these is tap it on the end with a hammer and punch.  Sometimes the shock of tapping on it will break it loose.  If the head strips out a little you can get another chance at it by peening the cross closed with a punch and hammer, just hit it a little harder than you did the first time.  If you are careful the sides of the cross will bend over a little and make for a tighter fit on the screw driver.  The screw driver may need to be tapped into place.

If the previous steps don't work (or someone else has already wrecked the screw like my project for today) you need to take more serious action.  On most parts you can grind or drill the head off the screw and then use vise grips to remove the left over stud after the pieces are taken apart. I like to use my set of left hand drill bits for this job.  Frequently when doing this the drill bit will catch on the screw and the torque of the drill will back it right out. 

Saturday, December 11, 2010

Yamaha Grizzly 700

Today I have a 2007 Yamaha Grizzly 700 in the shop for an electrical problem.  The machine would run fine, but it was not keeping a charge in the battery.  I checked out the battery and the main electrical connections.  Everything seemed fine so I moved on to the voltage regulator and stator.  There is really no way to test the regulator, but it is easy to check the output of the stator.  With the engine running you should see 20 to 30 volts ac on the stator leads.  This one showed no voltage. 

When I pulled the engine side cover off it was obvious that the stator was bad.  In the photo you can see burned section on the right.  I did a little looking around on the ATV forums and discovered that these Grizzly 700s frequently burn out the stator at about 4000 miles.  This machine made it to 5500. 


Friday, December 10, 2010

Welding - Sled Hitch

A lot of my time spent in the shop is on mechanic work, but I also do a far amount of welding.  Today I made a hitch for a snowmobile sled.  This is a very common welding job for me.  I seem to make a few every winter.  Unfortunately I forgot to take a picture of the hitch.

I did take a photo of my home made "fish mouth" marking tool.  When you weld two tubes (or pipes) together you need to cut a "fish mouth" into one of them to make them fit together.  There are several different commercially manufactured machines for cutting these notches,  but they are all rather expensive or require a selection of cutters matched to your tubing size. 

Over the years I have found that it is easy to cut these notches with an angle grinders if you have the tube marked properly.  The tricky part is marking the tube.

This photo shows the tube being marked on top.   My marking gauge can be adjusted to a wide range of tubing sizes and can also mark tubes that intersect at different angles.  Once the tube is marked I use one angle grinder with a .045 cutoff wheel to take the big chunks out and then another grinder with a regular wheel to trim down to the line.  With a little practice it only takes a few minutes for each tube.

Hopefully next time I'll remember to get some photos of the notches and the welding.

Tuesday, December 7, 2010

Kawasaki Bayou 250

I have a little two wheel drive 2007 Kawasaki Bayou 250 in the shop today.  I like this simple machine because it reminds me of my first ATV.  Back in the mid 1980s I had a brand new Bayou 185.  That is back when everyone else had 3 wheelers and I had a new 4 wheeler.  The machine seemed great back then, but it is laughable today.  Some of the special features it had were shaft drive, reverse, and electric start.  Some of the things that were missing are front brakes and rear suspension.  It had a solid rear end, I don't mean a solid rear axle like a lot of base models have today.  The rear end was solid, no suspension other than the tires!

The machine that is in the shop today has all the modern features.  It is in the shop because of a loose wheel  It wobbled around when you drove the machine.  I looked at it quickly a few weeks ago and assumed that it had a bad bearing.  I ordered a new bearing and shaft seal for it.  When I actually pulled it in the shop today and took the wheel off I realized that the hub was loose on the shaft. 

For some reason the hub was not seated all the way on the shaft and the shaft seems to have a lot of end play?.  I'm not sure what the problem is yet, I didn't get a chance to pull the shaft out.  As you can see in the photo the splines are a little wore out on the end, I hope I can get the hub back on far enough to engage what's left of the splines. 


Monday, December 6, 2010

Corroded Wire

I had a Honda ATV in the shop today that had a charging problem.  It took a while, but I eventually tracked it down to a corroded wire going to the voltage regulator. 

ATVs around here operate in a salt water environment and it leads to a lot of corrosion problems.  The voltage regulator on this machine is mounted under the rear fender near the tire.  It routinely gets sprayed with water and mud  in this location.  It appears that the insulation on the wire was cracked where the wire bent sharply going into the plug.  The cracked insulation let the salt water get in and corrode the wire.

It was a simple job to fix.  I trimmed out the bad section of wire and soldered in a new piece.  When finished I made sure to seal it up well.  I like to wrap connections like this with electrical tape and coat them with "Liquid Electric Tape."  In this case I was out of the Liquid Tape so I used tape a coating of RTV silicone.  Adhesive shrink tubing also works well, but you must have the type with adhesive inside.  The cheaper kind without the adhesive does not work as well.

Sunday, December 5, 2010

Frozen Honda Foreman

Today I have a newer Honda Foreman in the shop.  It went through the ice and spent a bit of time upside down and submerged in salt water.    The driver was cold and wet, but she is ok.

The top of the engine was full of water.  I pulled the spark plug and the water ran out of the cylinder.  I had to remove the exhaust to get the water out of the lower bends in the pipe and the muffler.  The throttle, choke and brake cables were also frozen.  The rear drum brake (that never works anyway on these things anyway) was filled up. The gas tank and the carb also needed to be cleaned out.  Somehow the oil in the crankcase and the front and rear differentials did not have any water. 

For most of the mechanical system being submerged is not a problem.  The real problem is the electrical system.  The machine was sunk in salt water, which is very corrosive.  Once that salt gets into the connectors there is no way to get it out.  It does not cause immediate problems, but I am expecting that this machine is going to have a lot of faulty corroded electrical connections in the years to come.  The salt can also be a problem in carburetors.  The salt deposits block up the jets and small passages and they cannot be dissolved, they must be scrapped or picked out.  Sometimes it is impossible to get rid of it all and the jets must be replaced.

Thursday, December 2, 2010

Flat Tire

After spending a few days in Elim doing building maintenace and a few days catching up on household stuff, I'm finally getting back to my regular mechanic work.  I have quite a few big jobs lined up but I decided to start the day off with something simple, a basic flat tire. 

I aired the tire up with my compressor and was able to locate the leak by the sound of the escaping air.  The leak was a small hole in the middle of the tread face.  This is a perfect candidate for a plug.  Plugs are so simple that they almost feel like cheating, but they are not.  For small holes in the middle of a tire they work great.  Large holes or anything on the side wall require patches.

To install a plug you just ream the hole out to clean it and make sure the plug will  fit.  Then put a little rubber cement on the plug (I only use the sticky covered string type, not the short rubber cones) and push it in.  Make sure you stop pushing when there is about 1/2 inch of plug left and pull the tool out.   If you are not careful you can push the plug all the way inside the tire.  That's all there is too it.  Total time 10 minutes.