Timing a 650 twin

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clive
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Re: Timing a 650 twin

Post by clive »

SOHC wrote:I was having brain fade there for a wile, I made a rod and marked off the top fin,

When I measure 11/32 off the piston and then check my degree disk it still comes up at 39 degrees BTDC
So long as you use the same point for both marks it does not matter what you check against. With my twin, with a competition tank, you can see the top fin even with the tank on. If you have a road tank you might not be able to see the top fin easily with the tank on for a subsequent timing check.

Worth checking the timing on both cylinders too as the magneto ring may be a little worn ( assuming you have one) and you may need to set it at a compromise to get the two cylinders firing at their best.
clive
if it ain't broke don't fix
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ajscomboman
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Re: Timing a 650 twin

Post by ajscomboman »

I'm with Clive, it'll not matter too much providing you use the same datum point.
G15 Roy
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Re: Timing a 650 twin

Post by G15 Roy »

ajscomboman wrote:I'm with Clive, it'll not matter too much providing you use the same datum point.
I never have a problem I just set TDC and then turn the crank shaft pinion back three teeth.
Roy
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ajscomboman
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Re: Timing a 650 twin

Post by ajscomboman »

That's coz you live a charmed life and have ME to bail you out of the s**t! :rofl: :rofl: :rofl:
G15 Roy
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Re: Timing a 650 twin

Post by G15 Roy »

ajscomboman wrote:That's coz you live a charmed life and have ME to bail you out of the s**t! :rofl: :rofl: :rofl:

OK so may be we will just do quick check on the Euro train on Monday then :lol: :lol:
Roy
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1608
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Re: Timing a 650 twin

Post by 1608 »

With all due respect to Clive , I wouldn't complicate matters by introducing doubts about the mag cam ring. Getting it right on just the one cylinder can be tricky enough.
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ajscomboman
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Re: Timing a 650 twin

Post by ajscomboman »

1608 wrote:With all due respect to Clive , I wouldn't complicate matters by introducing doubts about the mag cam ring. Getting it right on just the one cylinder can be tricky enough.
True it'll never ever be spot on on both cylinders but there are some cam rings about that are way out, I'm sure Groily will be along to confirm this, and so therefore it's worth just checking.
SOHC
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Re: Timing a 650 twin

Post by SOHC »

The mag was rebuilt by a magneto specialist who is very old now and forgot to tighten the inner cover and the center nut for the points witch caused me a lot of trobble with running problems.

Anyway the timing is set at 11/32, 39 degrees full advance now,
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