TDC and wiring loom

[welshmally]

Hi there,

I am trying to establish the most accurate method of finding TDC ('79 900SS with a RITA ign)

At present, I use a dial guage and chivvy the crank backwards and forwards using the back wheel with 1st gear engaged. I think it works OK but I'm not totally convinced it's 100% accurate.

It would be good to hear what other people do.

Also I am planning on installing a new loom and wondered if anybody out there had designed one to replace the cruddy Ducati original. A little Winter project.....

I'm going to give it a shot but may end up needing assitance, so any tips would be excellent.

Cheers

[machten]

At present, I use a dial guage and chivvy the crank backwards and forwards using the back wheel with 1st gear engaged. I think it works OK but I'm not totally convinced it's 100% accurate.

It would be good to hear what other people do.

A degree wheel and a piston stop is the best solution. You can make a piston stop from a spark plug. See below...



A degree wheel with crank turning handles, whilst not required (rear wheel is fine) is very handy, particularly for fine work like dialling camshafts. Singles wheel at top, twins below.


Then using your degree wheel you measure where at stops on a forward rotation and then where it stops on a reverse rotation. Half way in between is TDC (note you need to get TDC ignition). Then move your degree wheel accordingly and recheck. Continue the process until exact.

Also I am planning on installing a new loom and wondered if anybody out there had designed one to replace the cruddy Ducati original. A little Winter project.....

A few us have done a few for 750 GT's and Sports and are about to do one for a green frame. These are all very similar other than indicator wiring and wiring distances to headlight for the G/F. We had original looms to reference for all these bikes and measured them and made up a pegboard because we were making a few of them. A few people to help hold wires and read the colours is very helpful. Also whilst we respected the basic design and colour scheme, we used slightly heavier gauge wire and we added a few earth points into the loom.

Btw...bad luck at the rugby world cup. You were robbed! - as was the rest of the world of the potential spectacle of seeing Wales play in the final.

Kev

[welshmally]

Thanks Machten - I'll give that a go: it will make it that much more accurate than the dial guage I suspect.

Gutted about the rugby. We were at the Millenium Stadium - along with 65000 others. What an atmosphere! I have never in my entire life heard such a roar as that erupting when Mike Phillips went over the line - I am still tingling!

Sympathy to your guys too, but I felt you were definitely bettered today
How will I get to know about the loom?
WM

[machten]

WM,

I'll give that a go: it will make it that much more accurate than the dial guage I suspect

It at leasts takes out a bit of the "guessing" around TDC where the dial gauge doesn't move. You could probably achieve the same end by declaring a nominal gauge reading, say approximately 50 degrees before TDC, noting the wheel reading, then going past TDC until you get the same reading on the gauge, and take the degree wheel reading again. Once again TDC is half way between - adjust the degree wheel accordingly. I just find the piston stop a more positive (less fiddly) solution.

Sympathy to your guys too, but I felt you were definitely bettered today

That's putting it mildly!!! Completely outclassed. And if we play like that when we play Wales in the consolation game this weekend, we will be again!

How will I get to know about the loom?

Not sure what you're asking. I can get some photos of the pegboard, and we may even have taken some photos when we were doing the looms. I've got a PDF drawing for the roundcases with all the measurements, but it won't apply to the squarecases, of course.

Kev