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smooth runnings

Posted: Sat Feb 14, 2015 11:09 pm
by dorisandjack
evenin' all, not long fitted my hs4 carb and after a bit of mucking about with needles finally got the running about as bang on as it'll go without a colour tune, general driving is absolutely fine although the only issue seems to be (which is driving me round the bend) is that when idling and i depress the clutch and put it into first there is a fair amount of vibration and the revs drop steadily but considerably enough that the engine is nearly cutting out (sometimes will) along with this there seems to be a slight whir from the clutch itself, i would higher the tick over to counteract the problem but then it would be too high with the clutch depressed, as a result of this i normally have to blip the throttle slightly to pull off, could this be an ignition advance/retard issue? i was hoping someone might be able to shed some light on the brain frying conundrum!

Re: smooth runnings

Posted: Sat Feb 14, 2015 11:53 pm
by panky
Maybe running a little lean, have you tried the lift pin test?
Which needle did you settle on by the way.

Re: smooth runnings

Posted: Sun Feb 15, 2015 6:47 am
by kennatt
only since new carb,ok before that :-?

Re: smooth runnings

Posted: Sun Feb 15, 2015 9:31 am
by bmcecosse
Seems to me the clutch is being over travelled. Is there an inch of free play ? Don't waste money on colour tune - just use the pin as already suggested. And try a heavy oil in the dashpot. And indeed you should adjust the timing to get the smoothest idle. What manifold did you use with the larger carb?

Re: smooth runnings

Posted: Sun Feb 15, 2015 11:21 am
by dorisandjack
i tried M1 and BQ needles after reading the vizzard book but these were farrrr too rich, i finally settled for the AAU, i've just replaced the relay shaft bushes and spring both gearbox and chassis side although there's a lot of play in the linkages so I'm not getting much free play so i'll be replacing them too next pay check, should all be done at once i know but money runs thin on running projects! so maybe the clutch is disengaging too far??

Re: smooth runnings

Posted: Sun Feb 15, 2015 1:03 pm
by bmcecosse
It is - slacken off till you have an inch free play.

Re: smooth runnings

Posted: Sun Feb 15, 2015 1:05 pm
by Declan_Burns
The linkages that are being sold are rubbish. I had to re-bush them and still was not happy so I made my own adjustable link.
If anybody needs such linkages contact me.
I have being making stainless steel linkages and pedal box gaiter kits for MG's for some time using rose joints to eliminate play-see second photo.

[frame]Image[/frame]

MG clutch linkages
Regards
Declan[frame]Image[/frame]

Re: smooth runnings

Posted: Sun Feb 15, 2015 2:50 pm
by 123
dorisandjack wrote:evenin' all, not long fitted my hs4 carb and after a bit of mucking about with needles finally got the running about as bang on as it'll go without a colour tune, general driving is absolutely fine although the only issue seems to be (which is driving me round the bend) is that when idling and i depress the clutch and put it into first there is a fair amount of vibration and the revs drop steadily but considerably enough that the engine is nearly cutting out (sometimes will) along with this there seems to be a slight whir from the clutch itself, i would higher the tick over to counteract the problem but then it would be too high with the clutch depressed, as a result of this i normally have to blip the throttle slightly to pull off, could this be an ignition advance/retard issue? i was hoping someone might be able to shed some light on the brain frying conundrum!
Have you heard of "Plug chops" and / or "Cam dwell Meters"?
.

Re: smooth runnings

Posted: Sun Feb 15, 2015 5:50 pm
by bmcecosse
:o :roll:

Re: smooth runnings

Posted: Sun Feb 15, 2015 9:21 pm
by 123
bmcecosse wrote: :o :roll:
. . . :o :roll: . :D

Re: smooth runnings

Posted: Sun Jul 26, 2015 3:25 pm
by Declan_Burns
Here's a photo of the modified clutch linkage installed (without the dust boots).
Regards
Declan[frame]Image[/frame]

Re: smooth runnings

Posted: Sun Jul 26, 2015 4:26 pm
by bmcecosse
I'm surprised you haven't rose jointed the long link too Declan !

Re: smooth runnings

Posted: Mon Jul 27, 2015 6:22 am
by Declan_Burns
It's on the cards.
Regards
Declan

Re: smooth runnings

Posted: Tue Oct 27, 2015 6:53 am
by Declan_Burns
Here's a more detailed photo of the linkage. This is bolted up tightly between the relay shaft and the pedal and removes all play at this part of the clutch linkage. It replaces the metal plates and is adjustable by a few mm although that was not the object of the exercise. The chamfered brass spacer is a seat for the dust boot and prevents the boot being squashed when tightening the bolts.
Now on to the long link. I think this is a 5/16 UNF thread-can anybody confirm?

Regards
Declan[frame]Image[/frame]

Re: smooth runnings

Posted: Tue Oct 27, 2015 8:10 am
by IslipMinor
Hi Declan,

Definitely 5/16" UNF - please see the 'sticky' at the beginning of the 'Mechanical' section.

Re: smooth runnings

Posted: Tue Oct 27, 2015 8:29 am
by Declan_Burns
Thanks Richard.
Regards
Declan

Re: smooth runnings

Posted: Tue Oct 27, 2015 11:54 am
by danielvoorwerk
Nice new (for me too) project Declan !

Will do when swapping the gearbox soon (First finish my demper-overhaul, all parts sourced ;-)

Re: smooth runnings

Posted: Sun Feb 21, 2016 1:06 pm
by Declan_Burns
Here's the long link to match.
Regards
Declan[frame]Image[/frame]

Re: smooth runnings

Posted: Sun Feb 21, 2016 1:14 pm
by bmcecosse
Looks to be 'the business' - are you planning on selling it as a kit Declan?

Re: smooth runnings

Posted: Sun Feb 21, 2016 3:54 pm
by Declan_Burns
I might give it some thought with the dust boots as an option. The dust boots are the most expensive part at £3.43 each.
Regards
Declan