Night Train
Member
Sorry I got behind on this guys (and gals). This week we will talk about starters. Again, this is mainly geared around 05 and newer but some of this will pertain to the older bikes as well.
As you should already know to engage the starter it requires the key to be in the ON position and the run button must be pressed. When the start button is held in it grounds the logic signal coming from the EHC and tells the microprocessor in the EHC to engage the starter. At the same time the EHC will activate a separate output that will engage the compression reliefs for 1 second (regardless of how long you hold in the starter) and it will also disable the headlight output. Simplest way to test the compression reliefs is to put your finger in the hole
and feel the compression relief when you engage the starter. You should feel the valve open (plunger moves down) and then back up after 1 second. Do this for both cylinders. This will test if they are operating or not, you will need to do a leak down test or similar to see if they are sealing.
When the EHC sends a signal to the starter solenoid telling it to start what actually happens? The starter actually has two coils, the hold and pull-in coil. The pull-in coil does just that, when activated it will pull the plunger in so the plunger will connect the main contacts to allow higher current from the cable to rotate the stater. The pull-in coil will draw current just long enough to make contact and then the hold coil will take over and hold the plunger in until the start button is released. The pull-in coil has a higher current draw then the hold coil. The starter motor is basically a short circuit (very low resistance, higher current draw) until the motor starts to turn. The faster it spins the less current it will draw. There is a little more to it but sheds some light on the "delay start" when you have a low battery, until it is spinning it will draw more power from the battery. This does not mean stay in the starter for a full minute when the bike is not starting, the starter can overheat if engaged too long.
If you suspect a starter issue here are some things to look for: Oil in starter. Often times you will have a phantom oil leak and think it is the inner primary but it could also be coming from the stater. Some times it is not easy to see until the starter is removed and disassembled. Pitting on the main contacts. In a best case this can cause hard starting, in worst case it could let your contacts weld together. If you hear the starter engage but no spinny then disconnect the battery, pull the screws off the solenoid cover and remove the plunger (do not loose the spring). Look at the contacts, if they have severe pitting clean them up with some fine sandpaper and reassemble. In extreme cases you may have to replace the contacts. There was another post up here that said they used contacts from a dodge starter to fix the problem. I never came across this but you can't argue with results.
The very first thing you should do if you think you have a starter problem is have your battery checked. Have a load test performed with a tester that can test batteries down to 270cca or at least close to that. The cheap harbor freight unit probably will not work for you. If nothing else Walmart can probably test it for you. If the battery is good check all your cables and contacts, pay particular attention to the ground cable. The ground cable at the starter had a tendency to be over torqued and damaged the eyelet, this could cause loose connection and arcing, reducing the current carrying capability of the ground circuit.
Some have pm'd me asking about the 8-8.5v they see on the green solenoid wire when it is not connected to the starter. This is typical for the newer EHCs and is due to how the transistors are biased when there is no load on the solenoid wire. When connected this does not cause a problem or try to start the bike. The typical key off current draw we would see on a carb bike was about 1.28mA (0.00128amps) about 1mA of this was thru the charging system not the starter.
One last note, holding the throttle open while engaging the starter could cause the compression to increase by as much as 50%. This will cause the starter and battery to have to work harder and may cause the bike not to start. Follow the proper starting procedure as outlined in your owners manual.
Give me some ideas for next weeks topic, I'll see what I can do to accommodate.
As you should already know to engage the starter it requires the key to be in the ON position and the run button must be pressed. When the start button is held in it grounds the logic signal coming from the EHC and tells the microprocessor in the EHC to engage the starter. At the same time the EHC will activate a separate output that will engage the compression reliefs for 1 second (regardless of how long you hold in the starter) and it will also disable the headlight output. Simplest way to test the compression reliefs is to put your finger in the hole
and feel the compression relief when you engage the starter. You should feel the valve open (plunger moves down) and then back up after 1 second. Do this for both cylinders. This will test if they are operating or not, you will need to do a leak down test or similar to see if they are sealing.When the EHC sends a signal to the starter solenoid telling it to start what actually happens? The starter actually has two coils, the hold and pull-in coil. The pull-in coil does just that, when activated it will pull the plunger in so the plunger will connect the main contacts to allow higher current from the cable to rotate the stater. The pull-in coil will draw current just long enough to make contact and then the hold coil will take over and hold the plunger in until the start button is released. The pull-in coil has a higher current draw then the hold coil. The starter motor is basically a short circuit (very low resistance, higher current draw) until the motor starts to turn. The faster it spins the less current it will draw. There is a little more to it but sheds some light on the "delay start" when you have a low battery, until it is spinning it will draw more power from the battery. This does not mean stay in the starter for a full minute when the bike is not starting, the starter can overheat if engaged too long.
If you suspect a starter issue here are some things to look for: Oil in starter. Often times you will have a phantom oil leak and think it is the inner primary but it could also be coming from the stater. Some times it is not easy to see until the starter is removed and disassembled. Pitting on the main contacts. In a best case this can cause hard starting, in worst case it could let your contacts weld together. If you hear the starter engage but no spinny then disconnect the battery, pull the screws off the solenoid cover and remove the plunger (do not loose the spring). Look at the contacts, if they have severe pitting clean them up with some fine sandpaper and reassemble. In extreme cases you may have to replace the contacts. There was another post up here that said they used contacts from a dodge starter to fix the problem. I never came across this but you can't argue with results.
The very first thing you should do if you think you have a starter problem is have your battery checked. Have a load test performed with a tester that can test batteries down to 270cca or at least close to that. The cheap harbor freight unit probably will not work for you. If nothing else Walmart can probably test it for you. If the battery is good check all your cables and contacts, pay particular attention to the ground cable. The ground cable at the starter had a tendency to be over torqued and damaged the eyelet, this could cause loose connection and arcing, reducing the current carrying capability of the ground circuit.
Some have pm'd me asking about the 8-8.5v they see on the green solenoid wire when it is not connected to the starter. This is typical for the newer EHCs and is due to how the transistors are biased when there is no load on the solenoid wire. When connected this does not cause a problem or try to start the bike. The typical key off current draw we would see on a carb bike was about 1.28mA (0.00128amps) about 1mA of this was thru the charging system not the starter.
One last note, holding the throttle open while engaging the starter could cause the compression to increase by as much as 50%. This will cause the starter and battery to have to work harder and may cause the bike not to start. Follow the proper starting procedure as outlined in your owners manual.
Give me some ideas for next weeks topic, I'll see what I can do to accommodate.
