Thanks Trevor,
I wasn't checking the timing on the other cylinders, just using the light to
see whether the plugs were apparently firing OK. As number 1 and 6 do have the
same angle (firing order 1,5,3,6,2,4), and some Triumph material I have seen in
garages says the timing is done on number 6, I checked it expecting it to be
the same.
The distributor is near new with no side play in the shaft bearings.
Regards,
Bob Hutton
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From: Trevor Jordan[SMTP:tjordan@pa.ausom.net.au]
Sent: Monday, November 10, 1997 4:58 PM
To: Bob Hutton
Subject: Re: 2500 Timing
>Came across something strange on the weekend with my 2500 TC.
>Started out adjusting the timing and stripped the clamp bolt. Chucked that
>away and turned a collar out of large washer that now locks the
>distributor down with the two bolts that held the original clamp. I then
>decided to check the plugs by using the timing light on each lead to see
>if any were mis-firing. All were OK, but I noticed the timing on number 6
>was 2 degrees more advanced than number one. They should be the same,
>shouldn't they? It's a new distributor, how can this be?
>
>Comments gratefully accepted.
>
>Regards,
>Bob Hutton
Bob
I am not sure how you did this. The timing marks on the pulley are usually
set up for number 1. Is number 6 the 4th in the firing order? If so it
will have the same angle on the crankshaft as number 1. One will be on
power stroke when the other is on intake stroke etc.
It should not be possible to check the timing on the other cylinders as
they will be out of phase with the timing marks by + or - 120 degrees.
This may not be new to you, but I have never considered using a timing
light on the other cylinders.
Getting back to your question, I can only guess that it is a result of
inaccuracies in the points cam. Is it a perfect hexagon (manufacturing
variation and/or wear) and is it perfectly centred on the distributor shaft
- either would cause some variation between cylinders. Has it been
replaced recently and has it been properly lubricated.
You could try moving it around on the distrbutor shaft to see if there is
any improvement, but getting 1 and 6 into close agreement may shift the
discrepancy to the other cylinders.
A worn distributor shaft (like mine) should cause erratic timing and not
consistant differences like you have measured.
This is all just a guess, but I would be interested in any conclusions you
may reach.
Regards, Trevor Jordan
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