cliftyhanger
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 posted on 24/2/16 at 09:15 AM |
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Classic mini timing issue
Our classic mini (998) has been playing up, and about to get another dizzy that I am borrowing (so he thinks!) later today. It doesn't rev over
4k, but is on leccy ignition, so thought a swap to a points equipped dizzy will prove or eliminate that.
Anyway, the other issue is the timing. With old cars I have always set them by ear as fuels etc are so different today. The Mini is running at approx
30 degrees BTDC, turn it to 10 and it is rough as a rough thing. I have checked valve timing (correct) mixture is correct and not touched for years.
Head recently off, no valve damage at all, in fact very clean with no signs of pre-ignition damage that you may expect with those timing figures.
Anybody got any bright ideas? I have run out.
Cheers
Clive
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AntonUK
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| posted on 24/2/16 at 09:48 AM |
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Silly question but have you disconnected the vac advance when adjusting the dizzy?
Build Photos Here
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cliftyhanger
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| posted on 24/2/16 at 10:02 AM |
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Yep!
Sadly I have had to return the timing light I borrowed (mine died after being dropped) so will try theg new dizzy, set it up by ear, and see when I
can pilfer the timing light again. Bit chilly out there just yet, so may run some errands first!
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benchmark51
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| posted on 24/2/16 at 10:50 AM |
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Have you checked the bob weights and springs under the base plate in the dizzy?
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cliftyhanger
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| posted on 24/2/16 at 12:02 PM |
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Should have said, yes, had the dizzy out recently and checked it over. All seemed well and weights moving freely. Springs looked OK too.
(yiu can see why I am struggling !)
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MikeRJ
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| posted on 24/2/16 at 12:11 PM |
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quote:
Originally posted by cliftyhanger
Anyway, the other issue is the timing. With old cars I have always set them by ear as fuels etc are so different today. The Mini is running at approx
30 degrees BTDC, turn it to 10 and it is rough as a rough thing.
Sounds like your timing marks are not accurate. There's no way it's really running at 30 degrees advance at idle, you'd never be
able to start the engine.
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cliftyhanger
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| posted on 24/2/16 at 12:17 PM |
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That was my first thought, and why I checked the valve timing. This is all rather unusual. Stuff like this is simple. Usually.
Nearly finished this mornings jobs, then I will try swapping the dizzy.
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britishtrident
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| posted on 24/2/16 at 04:36 PM |
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My first reaction is check the piston is moving freely in the SU.
Also check the vac advance isn't detached from the base plate and give the centrifugal mechanism tiny drops of oi -- one on under the
rotor arm and one on each bob weight pivot via the hole under the condensor.l
But if is a timing problem try using the timing marks on the flywheel.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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02GF74
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| posted on 24/2/16 at 06:18 PM |
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Did you take the timing chain off? If so, was it put together with timing marks in line.
No air leaks on the inlet side, presumably it was removed when the head came off.
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steve m
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| posted on 24/2/16 at 07:12 PM |
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Has the damper on the carb got oil in it? and as said is it opening properly
is there enough fuel getting through
steve
Thats was probably spelt wrong, or had some grammer, that the "grammer police have to have a moan at
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avagolen
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| posted on 24/2/16 at 07:57 PM |
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Have you had a good look at the needle and jet in the SU.
If it is one of the self centring needles, it can wear the jet to an oval causing fuel mixture problems.
Took me weeks to find this on my Dads old mini years ago.
The Answer for everything, but never the last word....
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AntonUK
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| posted on 25/2/16 at 09:38 PM |
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dizzy drive a tooth out?
Build Photos Here
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rusty nuts
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| posted on 25/2/16 at 10:00 PM |
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Blocked exhaust? Faulty fuel supply/pump? Sticking piston in carb ? Siezed auto advance in distributor ?
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