So, the last thing was that the starter motor did not turn, or even click.
This turned out to be an easy fix. I consulted the manual, and found out that there is an electronic system that prevents the starter from turning if the sidestand is down, and if a gear is engaged without the clutch being pushed in.
I could easy narrow it down to the neutral switch connector, since I had not connected it.
The neatrual switch connector is behind the front sprocket. With only one cable leaving it. The cable is connected to ground when in neutral.
I cut of the connector with a piece of cable from the 850 engine and soldered the cable coming from the 900 engine.
Then added some insulating tape. Since the connector is from the 850 engine it will fit to the harness.
Then test to crank around the engine. The fuel filter and pump and the gas tank was fitted. The fase cables from generator were fitted, and the cables for the pickup coil.
The bike was ready to start. And the starter cranked the engine now.
But it would not start, It kinda ignited a little sometimes, but did not start.
Then I put the charger on to charge the battery, and went to inspect the 850 engine, and find what differed.
After a while I found these "cogs" on the outside of the rotor that go to the pickup coil and gives the ignition timing.
Then I took of the generator cover from the 900 engine to inspect the 900 rotor, the "cogs" are different. It all became clear.
On the 900 rotor (on the left) there are a great number of cogs with an even pitch. On the 850 rotor there are a smaller number of cogs, and in a more random order. The cogs on the 850 rotor where arranged so that the spark would be timed. The bike would obviously not run with the 900 rotor, since the ignition timing was completely of
I think that the cogs on the 900 rotor are for giving an exact engine speed with a good resolution to the ignition control unit. Complemented with another signal from a sensor on the exhaust camshaft, that indicates every turn of the camshaft/engine.
What to do know? Can I get the bike running? I even posted here asking for advice.
Note that in the reality the rotors are not removed yet.
Removing the bolt from rotor, the easy part.
Here are the bolts holding the 850 and 900 rotors. They are identical.
Preparing one of the bolts with the lathe.
The first attempt with some kind of rotor removal contraption, it failed of course
Then, after reading about some kind of special removal tool, and finding three M8 threaded holes in the rotor, work with designing a special tool could be started.
I took a used pulley, made a grove with the right diameter in the lathe....
And drill 3 holes in it with 120 deg pitch. Same bolt pattern as the threaded holes in the rotor. The bolt pattern didnt match perfectly, but good enough.
Then turn away some more material
Prepare some bolts, and assemble the new special tool
well, until now it was easy. The rotor did not want to let go of the crankshaft.
I tightened it down properly, used a small hammer, then the bigger hammer, nothing.
Tightened the bolts down some more.
I did not want to heat up the rotor, or use too much violence, the magnets could get damaged.
I bought a pneumatic rivet hammer, since some had succeeded using one. Hamared with it until I destroyed one of its tools.
After two days with the special tool applying pressure the rotor it finally let go of the crankshafts end.
The same procedure on the 900 engine went much easier. Maybe because it has not run as many miles.
Here are the tools I used. The thing with 3 arms, is not really necessary tho
Then the both rotors could be compared. And great success. It seemed to be the same taper on both rotors.
I did some measuring on how the axial position would be of the 850 rotor in the 900 engine, and it would fit perfectly. Great.
Behind the rotor there is a freewheeling gear for the starter. The freewheel is engaging the rotor, which is connected to the crankshaft. In the part catalog the 900 and 850 gears have different part numbers, when comparing them, the only difference is that the 900 gear is made lighter.
On my 900 engine I use the 900 starter freewheel sprocket with the 850 rotor. Works great.
Then clean everything of, put back all starter gears, tighten down the rotor centre bolt, put back the generator cover. And startup. It fired up almost immediately, and run great. Nice.
I let the bike run for a while. Checked the coolant level. There was some smoke, but that is expected.
Next, fix the chain, and the first ride.
Edited by anda3243, 09 January 2012 - 11:25 pm.
