ATV Throtle Cable Replacement

I had a Yamaha Grizzly in the shop with a bad throttle cable.  Whenever the temp dropped below freezing it would get stuck.  There was obviously some moisture in the cable somewhere.  When I checked it out I discovered that the jacket on the cable was broken in the middle and it would need to be replaced.

I removed some of the plastic body work and took the covers off the throttle control on the handle bar and the cable cover on the side of the throttle body.  To provide a little slack in the cable to remove it I opened up the throttle butterfly and stuck a screwdriver in there to hold it open.

Once there is a little slack in the cable it is a simple matter to twist the cable end around and slide it out of the slot.

The end on the handle bar comes apart in the same way.  Get some slack in the cable and twist it around so that it can lift out of the slot.  Once the cable ends are free the outside housing unscrews from each end.  When installing the new cable remember to adjust the cable free play and use the lock nut to hold it in place.

This last photo shows the old failed cable assemble and the new replacement.  There are two pieces of plastic tubing slipped over the cable housing to protect it from abrasion.  Where the two pieces meet in the middle the housing broke.  I don't understand why Yamaha made it this way?  If the outer tube was one piece it would avoid that kink in the middle.  When I installed the new one I put a few wraps of electrical tape around it to try and avoid this problem.

ATV Brake Bleeding How To

Most modern ATVs have hydraulic brakes that rarely need servicing, but once in a while I do have to work on them.  I have found that they can be stubborn to refill with fluid and bleed if the system has been opened up and all fluid drained out.  These photos show the brakes on a Yamaha Grizzly, but most machines work the same way.

After reassembling the system I connect a hand operated vacuum pump to the brake bleeder using a piece of clear tubing.

Fill up the reservoir with fluid, put a little vacuum on the bleeder, and slowly open the bleeder.

The vacuum will pull the brake fluid and any trapped air through the system.  The clear tubing will show the air bubbles escaping.  When the bubbles stop and there is only clean fluid coming out the brakes are properly bleed.

It is possible to bleed the brakes without the vacuum pump, using only the master cylinder to push the fluid through, but I have found that it can take a very long time.  The hand vacuum pump is an inexpensive tool that speeds up the process.

ATV Wheel Bearing Replacement

Wheel bearing replacement is a common job on ATVs.  This machine is a Yamaha Grizzly, but most machines are put together the same way.

Once you remove the wheel the first step is to remove the large nut that holds the hub on the axle.  On Yamaha machines the nut is locked in place by a small portion bent into a groove on the shaft.  I use an old screwdriver that I have ground down to match the groove to pry this spot out.

The easiest way to remove this nut is with an impact wrench.  If you do not have an impact wrench you need to find some way to keep the hub from turning.  One way to do this is to put a pry bar between the wheel studs.  Be sure to protect the threads on the studs with a short piece of rubber hose if you are going to pry on them.

Once the hub is off the spindle must be removed from the vehicle.  The ball joints (red arrows) and the steering tie rod (green arrow) need to be disconnected.  These are held in place with a nut on the end of a tapered shaft.

Remove the nut and pry or pound the ball joint loose.  If you are going to pound on the threaded end use something soft like a lead hammer to avoid wrecking the threads.  The other tool pictured is a ball joint fork, it is simple pounded in between the parts and the wedge shape drives them apart.

When you have the spindle on the workbench remove the clip that holds the bearing in place.  This one has holes in the ends that make it easier to get out. 

If you look close at these clips you will note that one side has sharp edges and the other side has edges that are rounded over.  (The top clip is sharp side up, bottom clip is round side up, it is more obvious in person than it is in the photo.)  These edges are a result of the way that the clips are stamped out when they are made.  When installing clips like this you should always put the sharp edge facing the direction that the clip is being pushed towards.  The sharp edge makes it less likely to slip.  In the case of these wheel bearings the sharp edge goes up.

To remove the old the old bearing I use a large hammer and a piece of pipe to pound the bearing out from the back side.  I do quite a few of these wheel bearings so I have made up a jig to hold the hub when I pound on it.  Make sure you have something solid to pound on.  I have an old cast iron weight from a tractor (about 75 lbs) that I put on my workbench.  In my old shop in Minnesota I had a large anvil to pound on.  If you don't have an anvil you may want to put your work on the floor.

Before you in install the new bearing you must make sure that the inside of the hub is clean.  Make sure there is no crud at the bottom of the bore or in the groove around the top.  Scrape or wire brush it out.

Heating the hub will cause it to expand and allow the bearing to go in much easier.  I use an electric heat gun, but a torch will also work. 

When installing the new bearing you can only push or pound on the outer race (green arrow).  If you apply any force (especially pounding) to the inner race or seal (red arrow) you will damage the bearing.    If you heated the hub up enough the bearing will drop in with only a few minor taps.

On this job I used a hammer to pound out the old bearing and tap in the new one. It may seem a little crude, but with care it works fine.  A hydraulic press could also be use to remove and install the bearings.  It would give a little more control, but the rules about protecting the inner race still hold true.  You must only push on the outer race.  An old bearing that has had the outside diameter ground down slightly makes a good tool for this job.  It can be used to press the new bearing in place and insure that the force is applied evenly.

Once the new bearing is seated all the way into the bore, install the clip to hold it in place.  Now the hub is ready to go back on the vehicle. 

CV Boot Replacement

The Yamaha Grizzly that I have in the shop also has a couple of CV shaft boots that are ripped.  This is an important thing to fix as soon as possible.  If you operate a vehicle with ripped or torn CV boots the grease can get washed out and dirt can get in, this will quickly wear out an expensive CV joint.

Replacing a CV boot is a simple job.  Here are all the parts and pieces laid out on the work bench.  The grease in a CV joint is always messy, this is one of the jobs where I wear gloves.  I did not take any photos of taking the joint apart (mostly because I was covered in grease), but it is the opposite of putting it together.

First slide the clamp and boot on the shaft.

Slide the next pieces on the shaft.  They could be held on with a spring clip or a snap ring like this one.  When installing a snap ring take a close look at it before putting it on.  One surface has square edges and the other surface will have slightly rounded edges, this is a result of the way that they are manufactured.  You should always install them with the square edge in the direction of the thrust.

The next step is to put the balls in place and pack everything with grease.  When you buy new boots they normally come with the correct grease to put inside.

This photo shows the clamp being placed on the boot.  The clamps come in many different styles.  This one is easy to put on, you simply push the end down to tighten it and then bend the tabs over to hold it in place.  When installing the clamp you should put it on in the direction that would be less likely for the end to snag on something when it is spinning.

Here is the completed clamp with the tabs bent over.  Once you have the joint back together you should check it to make sure that it plunges in and out properly.  As the suspension goes up and down the axle length changes and that change is taken up in the CV joint.

Now the axle is ready to be installed in the vehicle.

Yamaha Grizzly 700

I have a 2008 Yamaha Grizzly 700 in the shop today.  This machine was in a minor collision and the front suspension was damaged.  The lower A-arm was bent and eventually broke after driving on it for a while.

This photo shows the broken A-arm.  The lower red arrow points to the break in the A-arm.  The upper arrow points to a cracked CV boot.  While I have the machine in the shop I am going to change the cracked boots and change the wheel bearings also.

C.O. 

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.

  

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. 

C.O.

Yamaha Grizzly 450

Today I am doing a basic u-joint change on a Yamaha Grizzly 450.  The owner changed a front wheel bearing himself, but did not want to change the u-joints on the rear drive shaft.  This machine has 9600  miles on it and the wheel bearing and u-joints are the only problems that the machine has had.

The drive shaft is very hard to get to, even after removing the skid plate from the bottom of the machine it is difficult to access.   Other than that it was a typical u-joint job, press or drive the cups out of the yokes, clean the yokes up (a round wire brush in a drill works great), then press the new cups in.  After finishing the drive shaft I fixed a leak on a front brake line (from the owners bearing replacement).

Total time on this job: 4 hours.

Yamaha 550 Grizzly

This machine is only 6 month old and still under warranty. Normally the owner could just take the machine back to the dealer and get it fixed up for free.   Unfortunately it costs several hundred dollars to put it on a plane and fly it back to the dealership.   I end up working on new machines like this frequently.

This is the same machine that I talked about in a previous post.   One of the bolts that holds the clutch pilot bearing support came out and flew around inside the clutch cover.  The belt was destroyed and the clutch faces were severally chewed up.  I talked to the dealership where the machine was purchased and they agreed to send me the new parts for free.  The owner is going to have to cover my labor cost, but at least they got the parts.

When putting the secondary clutch back on you need to tighten the nut to 70 ft lbs.  That is an easy amount of torque to achieve with a long wrench, but it is almost impossible to hold the clutch from turning.  I made a special tool to hold the clutch.  I used an old 1 7/16" end wrench to make a special spanner wrench.  I drilled two holes in it and put two short 1/4" bolts through the holes to line up with the holes in the clutch.  It may not look pretty but it worked great.

Yamaha TTR 50

Dead battery, drippy carb, stuck throttle cable, strange ticking sound.

I'm looking forward to fixing it so that I can take it for a test drive.

C.O.

Yamaha Grizzly 550

Someone brought a Yamaha Grizzly 550 ATV over for me to look at. They said that it made a bad grinding sound and became very hot when they drove it.

I took a look at it and noticed that the top of the engine was covered with black dust. This machine, like a lot of newer ATV's, uses a belt drive CVT similar to the drive train on a snowmobile. On closer inspection the dust looked like the residue from a worn out drive belt. I took the cover off the clutches and discovered that a bolt had come loose and had been rattling around inside the cover. The belt was destroyed and the clutches are beaten up pretty bad.

The machine will need a new belt and I am going to recommend to the owner that the primary clutch be replaced. There is not much labor in this job, but the new clutch will be expensive.

Interestingly, this is the third Yamaha with clutch problems in the village in the last few months.

C.O.

Yamaha Outboard

Sometimes what's in the shop, isn't in the shop.

We have a lagoon near our village that makes a natural harbor where you can keep your boat safe from the big waves on the ocean beach. This is where most people keep their boats. Today I was down at the lagoon working on a newer Yamaha outboard. The owner told me that the wires from battery get hot enough to smoke and the motor is hard to start.

It turns out that the main battery cables had a small damaged area that had allowed the copper wires to corrode. The corroded section of wire caused so much resistance that the wires did actually heat up and smoke when you tried to start the motor. The salt water environment is hard on electrical equipment.

It was a simple job to cut off the wires before the bad spot and put new terminals on the ends. I crimped and soldered the new terminals on and reconnected them to the motor.

C.O.