Sunday, April 19, 2015

What a difference...

An O-ring makes.
I should be writing lyrics, not playing with bikes. Oh well. 
The various seals I ordered all turned up quick smart from Blue City Motorcycles, in South Australia, with free postage too! Cheers guys. I also found their prices to be cheaper than most so happy with that.
I'd left the oil pump in a container of oil all week, pumping it every now and again to make sure there were no nasties inside. It looks perfect. With new O-ring held in place with some grease, it was ready to be refitted. 




Three M6 bolts hold it in place, then a thrust washer is fitted before the drive pin is inserted and then the gear can be pushed onto the shaft. Finally, a circlip holds it in place. 





Tip: Hold the gear and turn the circlip round with a screwdriver to make sure it's sat in its groove properly (if it isn't seated, it will be hard to move, or will fall off - better to find out now).

Because I'd left the oil in the sump (the beauties of working on the side stand), I could now turn it by hand and feel if it was pumping. Turning it clockwise, you can feel it get harder to turn as the oil is pulled up and forced around the galleries. As I continued to turn it, the oil was pumped up into the countershaft, out through the drilling and the end of the shaft itself. Perfect.




All that was left was to wang the clutch back together and spin it on the starter. With thrust washer refitted to the countershaft, the oil pump drive gear and pin were put back onto the back of the clutch basket. I used grease to make sure nothing dropped off while the clutch basket was reinserted. Once aligned with the gears, the needle roller bearing and sleeve were pushed back in. 
If anything, the sleeve feels a little tight in the bearing, but it does have oil pressure-fed through it. I'm going to let this one ride because I need to find out how the rest of the engine will stand up first. After a good flushing, we'll have a better idea on what needs to be fixed.
Another thrust washer goes on the outside, and then the clutch hub can be refitted with the tab washer and nut. With nut torqued up and washer bent over, the plates were refitted. Lastly, the pressure plate is put on and secured with the springs and four M6 bolts. 
I hooked up the test light to the battery and tried it on the starter. 'Tis a beautiful thing.



The oil pressure light circuit.
When you know how something works it's great, it's simple, and becomes second nature. But until you know, it can be the most complex thing ever. Vehicle electrics are like that. How does a switch at one end of the bike, make a light work at the other? Hopefully this will make it a bit easier.
In my test, I don't have any loom connected on the bike and no clocks/lights etc., so I used my test light instead. 
We're using an earth return as per normal i.e. earth leads connected to frame, engine and negative terminal on the battery. So every electrical component needing an earth/negative to work, can take it from any of these points.
Now we need the components to make a circuit which are as follows:
  • Battery
  • Oil Pressure Switch
  • Light Bulb
  • Wire
The oil pressure switch is very simple. The body of the switch is connected to the battery negative via its fixing to the engine (remember the engine earth lead). The switch contacts are closed at all times while there is no oil pressure - so current can flow. When the engine is turning, oil, under pressure, flows into the switch and deflects the diaphragm, opening the terminals and breaking the circuit.
With ignition on, one side of the bulb in the dash is connected directly to the positive terminal of the battery, the other side makes its way down to the switch in the engine. Current can flow right round and make the circuit complete. And that's why the oil light is on until the oil pressure opens the contacts in the switch. It's that simple.

More soon folks.