Thread: fitting distributor gear

with the #1 @ TDC and both its valve rockers loose #4 valves should both have tight rockers. This means that #1 is post compression pre power stroke and both valves are closed #4 is post exhaust, pre intake stroke and both valves are partially open (AKA on the rock) If thats not the case, turn the engine over 180 degrees and check off on what 2+3 are doing. then turn over another 180 degrees and recheck har 1+4 are doing.

If you cant get a bead on whats happening with the valves at this point redo the valve adjustment and If it still doesnt work out then the cm timing is off.

Assuming that you hace get #1@tdc with both valves closed...

drop the dizzy in and wiggle it round till it slides in and engages in the drive. wherever the rotor arm points is the firing position for #1. You're not timed in yet, you're what I call "Correctly phased" (assuming you get the firing order correct on the dizy cap

To time the engine rotate the engine 300ish degrees and watch for the timing mark as you go a further 60 degrees. Stop when you hit the timing mark alignment. Now you will be at the correct static timing for #4. connect a test light from bat+ to your points connection and "bracket" the position that turns the light off. Once you have that worked out rotate the dizzy against the direction of rotation of the rotor until the light comes on and then rotate back until the light only just goes out. lock the dizzy.

Rotate the engine 300ish degrees again and with the timing light in a position where you can see both it and the timing mark turn the engine again untill the light goes out. If you've got it all right it will turn off as the marks align and you now have a correctly timed engine. all you have to do is put the cap on with the leads in the correct position.

Thanks Dave,
My problem is/ was the point before this.
Getting the Dissy drive in the correct position, and installing the grub screw.
Spent the afternoon, looking at the manuals, then going to the shed.
Camshaft timing mark, set inline with top timing cover bolt hole, as per manual pics.
Dry run, problem being as I dropped and turned the gear, the grub screw hole would not be in the correct position.
Also the master shaft position, did not seem to be at 20deg.
Found after cleaning the drive and oiling. Setting the groove at about 3 o clock everything, except the grub screw seemed correct. The oil held the bush, so rotated the camshaft, until the hole came around,
screw driver to raise it slightly, the inserted the grub screw.
so I think that part is correct.

whitehillbilly

So when you finally fire her up and she runs backwards

I hope you realise that you're giving a valuable tutorial for those of us who haven't started our engine rebuilds yet - it's not just the questions you're asking but also the detail you're willing to go into. Thanks.

Hi Crackers,
Funny you should say that.
Fired up my Bultaco Trails bike years ago, put it into first, let out the clutch and ran into the wall behind me.

whitehillbilly

the orientation and setup of the gear and screw isnt critical so long as the screw engages properly.

engaging the oil pump drive and the final phasing and timing is

Hi Dave,
What difference does the engagement of oil pump drive make?
The gear has a master spline, but the oil pump drive shaft doesn't?
Or do you mean it has to go down far enough? So the screw locates in its hole?

Whitehillbilly

Originally Posted by whitehillbilly64

Hi Dave,
What difference does the engagement of oil pump drive make?
The gear has a master spline, but the oil pump drive shaft doesn't?
Or do you mean it has to go down far enough? So the screw locates in its hole?

Whitehillbilly

its got to go i nso the screw engages correctly and engnging the gear on the oil pump drive is important because the 2.25 doesnt usually have a long life if the oil pump isnt turning

Thanks Dave
Think I need to take it apart, Photo the reinstall, with lots of pics, for those following in our foot steps.

whitehillbilly