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Jack shaft timing marks

Posted: Mon Sep 27, 2021 10:36 pm
by Matt Cotton
Hi all.
I'm replacing the timing chain on my Sprint. I've made sure the crankshaft and camshaft timing are aligned as per the workshop manual and the rotor arm is currently pointing at no1. However the jackshaft markings are around 90 degrees out? There are two markings at 12 and 6 o'clock.
If I rotate the shaft so as the markings are at around 3 and 9 o'clock or between the two bolts as stated in the manual, then the rotor arm is at no4 plug?

I'm not sure why this is the case? I favour leaving as it is as the timing was fine before I started the replacement.

Any thoughts folks?
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Re: Jack shaft timing marks

Posted: Tue Sep 28, 2021 12:21 am
by Mad Mart
As long as the dizzy clamp bolts are roughly in the middle of the slots (for maximum adjustment either way), it will be fine.

Re: Jack shaft timing marks

Posted: Tue Sep 28, 2021 8:51 am
by Matt Cotton
Thanks Martin.
I've just had a look and the dissy clamp bolt is right over to the left... Someone has been here before I feel!

With this in mind, am I best off to align the jackshaft as per the manual at point 'D' and then centre the dissy shaft accordingly? I will need to check the timing afterwards, but as it is there is no way of advancing if required.

Kind regards Matt.

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Re: Jack shaft timing marks

Posted: Tue Sep 28, 2021 9:40 am
by Mad Mart
Put the clamp bolt in the middle of the slot and tweak it down. You will then need to move the jackshaft one tooth at a time to get the rotor arm in the correct position. It will probably only be one tooth out.

Re: Jack shaft timing marks

Posted: Tue Sep 28, 2021 9:56 am
by Matt Cotton
Will do Martin. Thanks for your help with this one.

If I mash the valves I will send it down to Weston for a holiday!

MC

Re: Jack shaft timing marks

Posted: Tue Sep 28, 2021 12:12 pm
by Mad Mart
Matt Cotton wrote: Tue Sep 28, 2021 9:56 am If I mash the valves I will send it down to Weston for a holiday!
Don't do that, I live in Winscombe now. :lol:

Re: Jack shaft timing marks

Posted: Tue Sep 28, 2021 12:14 pm
by yorkshire_spam
Turn over gently by hand before any attempt to start! Some of us may well have learned that particular lesson the hard way in the past. :oops:

Re: Jack shaft timing marks

Posted: Wed Oct 13, 2021 11:45 am
by Matt Cotton
I'm pleased to say the car starts and sounds ok!

Thanks for the help gents.