Big Ed's Workshop - Starter motors
Keeping a motorcycle maintained is important not only for the health of the machine but also for your own safety. Through this Bikers Guide I'm going to give you some top tips for doing work yourself, not only to give you a better understanding of your bike, but also to save you some pennies!
Why it's important:
Starter motors do give up the ghost, its a fact. They get used to power up your engine every time you hit that button and thats a hard job and any piece of machinery would wear up. Often though before running out and buying a replacement it might be worth having a look inside. In many cases you'll just need to change the brushes and clean her plates up and she'll be ready to roll. This guide should help you to do that...
Let's get to work:
Track down your starter motor. It'll be somewhere on the edge of the engine, usually front, behind the pots or underneath. You'll see a wire coming from it, thats the live, disconnect it. Once that's done you'll want to undo the mounting bolts at the rear of the motor. Once you've done that it will probably sit in position, give it a pull and she should come loose. If its pretty locked in give it a tap with a hammer and it'll drop off.
Now you've got your motor off its time to get inside. Place it into a vice by the gear end and you'll see two long bolts that run down the outside of the motor, undo them. Now Carefully slip the outer casting off. There are magnets involved so be careful as bits can fly out and you don't want a collection of washers all over the garage floor. Once the outer casing is removed you'll see the armature running down into the communicator and the gear at the bottom, remove this. Again be careful to remember the order the washers come out as they'll have to go back in that way.
Now you've got the front end of your starter motor looking back at you. You'll see a little plate that runs around the edge, on here are wires and two brushes. If your motor is totally defunct there won't be much material left on them at all. You should be able to pick up some brushes from your local motorbike dealer and they shouldn't cost you more than £15. Compare the new to the old and you'll see why your motor wasn't working. The brushes will be attached with small bolts to the plate, undo them and pop in the new brushes.
Clean up. Give all the plates in your motor a good clean up. I give them a gentle rub down with wet a dry just to boost the contact points. There'll be a lot of dust about to, blow that out. Now you're ready to reassemble.
This is the tricky bit, you'll need to get the armature and place it back inside the outer casing. With the front end in the vice you've got to get the motor back together with the brushes on either side of the communicator. Which is difficult because they won't hold in place, with a bit of skill and some tiny screwdrivers you'll be able to slot it into place. Don't forget to put your washers back in! Make sure the marks on the outer casing line up and pop the long holding bolts back in.
Right you're all done and your motor should be ready for action. Pop it on a battery with a good earth and give it a test, it should werr into life. Now fit it back to the bike, giving it a gentle tap to return it into position, then replacing the bolts, and of course the live wire. Now she's all back together and you'll be ready to ride!
Hope this guide has helped, let me know if you've got any questions on my Facebook Page. Ride on!
21.06.13 - Big Ed