JET SKI STARTER MOTOR EXPLAINED
You go to start your jet ski ,there is a click or just silence,and then nothing. Sound familiar ,no roar as your engine comes to life , just a depressing feeling that you are not going out on your jet ski today.
The jet ski starter is a fairly simple mechanism , a small motor that uses torque multiplication to turn over the much bigger main jet ski engine. On most Jet skis, except the very small capacity units, the starter driving gear engages with a reduction gear cluster that allows the relatively weak starter to turn the engine over fast enough for it to run on its own. There is one manufacturer who uses a direct drive from the starter motor to the ring gear on the outside of the flywheel even on their larger capacity boats. Sea Doo 's use this direct drive and although it seems less reliable it works very well.
When you are experiencing jet ski starting problem be sure to make sure that the battery is fully charged , and that all the cables are firmly in place with no signs of corrosion. Do not forget the earth cable. How many times have you seen someone ready to kick there jet ski to death ,when there jet ski won't start, even though it has a fully charged battery. Only to find out later that corrosion and electrolysis is the cause of its failure to start.
A common problem in many starters sea doo 800 in particular ,and one that is easily and cheaply remedied by the average D.I.Y mechanic. The commutator brushes that are inside the jet ski starter motor,and that conduct current quite often wear out or become broken.
The replacement brush sets are just a fraction of the cost of a new starter and fairly easy to install on most jet skis.
The first thing to do is to disconnect the negative battery terminal and remove the main starter cable from the starter body.
With these out of the way it will be much easier to get at the starter mounting bolts. If your model has a ground cable that is attached near the starter then remove it also.
At the rear of most starters there is a rear support bracket, remove the bolt that goes through this bracket. At the front of the starter there will be the two mounting bolts.
These are usually 8mm bolts, when these are removed the starter will be free to pull out backwards an inch or two and then be freed from your jet ski engine.
With the starter out of the engine and on the bench you should do one test before taking it apart. Take the main starter wire that you removed from the starter and remove it from the solenoid .
Then attach it to its mounting post on the starter body, attach the other end to the positive side of the battery. Hold the rear of the starter to the negative post of the battery.
If the starter turns over furiously then you can be fairly sure that the problem is in the solenoid, not the starter motor itself, if so then replace the starter and remove and replace the solenoid. If this test does not turn the starter over then disconnect the wire and proceed to the disassembly process.
Disassembling the starter:
First thing to do is to remove all grease and foreign material from the outside of the motor body, with a clean outside body mark the body with a line from a felt marker from one end to the other. This mark will prevent you from putting it together incorrectly later. If you are unsure then go one step further and mark the main pieces from one end with numbers or letters so that there is no mistaking which parts go where later!
At the rear end of the body there are two bolts that go all the way from one end to the other, remove these bolts. At the post where the main starter cable connects you can remove the jam nut and this will allow the brush to be released when you pull the body pieces apart.
Carefully remove the now loose rear cap from the starter, you will see that the brush plate within the starter wants to come out with it. Go ahead and remove the brush plate with the rear cap but do try and mark its position with the marker before you really get it separated, once again this will ease the assembly later.
If your starter is like most I have ever seen then your problem will be fairly apparent at this point. Most often you will see that the brush that is supposed to be connected to the post is either dangling off the brush or hanging off the post but not joined to both. If this is the case then go to your jet ski dealer for a a replacement, simply reverse the process and your jet ski starter motor should be working again.
If the brushes are not broken or worn it is probably time to get some professional help, rewinding a starter is a job best left to a professional jet ski shop. |
