ET: Engine (Twin) Timing

[oexing]

Even so - don´t trust anybody without checking everything. Especially old marks in the timing box. You mostly don´t know the history of the previous owners messing with the bike.

Vic

 

[lee_812d]

Damn, I'm not going to get any sleep now! Yes it has been pointed out more than once that I got the number of teeth wrong.

 

[MichaelOrgzey]

Well, there is a bit an error creeping in here. The half-time pinion has 24 teeth and once the large idler is spun all marks go out of line, so the "misalignment" of the half-time pinion alone is not a function of the hunting tooth. In any case, Big Sid probably got it right and if the bike goes well then best leave it alone

I definitely will

 

[lee_812d]

With 24 teeth, the number of turns is 23 and 56. It's only of academic interest, if that, and of no benefit to doing the job.

 

[craig]

So cam timing at crossover point I am at 5°BTDC on rear and at 2°BTDC on front with 0.058" lift using Mk1 cams.
Close enough for rider Rapide?

 

[oexing]

Now that looks very scientific ! At this stage I´d recommend marking the cam gears and engine case like in my photo. So later you don´t have to do the full Monty for finding equal lift overlap. You just set rear gear to its corresponding marks and install the half time gear at 4 degrees BTDC crank position - done. Then when you are lucky, turn the crank 360 plus 50-4 degrees for front cam gear and it should just slip into mesh at marks. Or so I think to remember , was a year or two ago for first engine.

Vic

 

[erik]

I made this tool to avoid fighting against the power of the valve springs .And you can leave the ufm in situ.Gruss Erik

 

[vibrac]

Neat tool! quite enough for road use and who wants to lift the ufm however it cannot be as spot on as gauges on valve stems

 

[oexing]

Erik, your idea looks quite useful when changing components in the timing side with engine in "frame". Allright with engines and no ratio in rocker lengths, no way to do that in Horex Regina, different cam lifts due to different rocker ratios. But best way is to mark timing gears and corresponding marks on engine case - unless you change cams and gears so you´d need new marks.

Vic

 

[erik]

In this case I have changed the camshaft because a Megacycle "racing" camshaft was mounted.I changed back to standard.To my mind better for a roadgoing Vincent. Erik