Setting distributor timing from scratch

[kennatt]

sounds as though the revs are too high at tickover,unless its the recording,if they are then you will not get a result with the lift pin, since revs too high, lift the needle up from the jet so you cant get the pin to touch the barrel in the dash pot to lift it for checking.If you had to put heater on to cool it down then you may also have a cooling issue The minor is generally overcooled .

[Napoleon Boot]

Thanks Kennatt,

The revs are really high at tickover - if anything it sounds worse in real life than in the video! Re: cooling, I'd topped up the coolant before leaving home and the level hadn't dropped when I returned, so there's no leak. I read elsewhere that symptoms of retarded timing include loss of power and increased engine temperature. Assuming the fuel mixture is correct (I looked at the carb needle last month and it's in mint condition and properly set), could advancing the distributor bring back the power and lower the engine heat by making sure the fuel ignites at the right part of the piston's travel? If this works, I can then lower the idle revs using the screw on the top of the carb.

By the way I topped up the carb dashpot a few weeks ago and the cylinder looks fine.

I'm thinking aloud here really, please let me know if this sounds plausible! I'll have an experiment tomorrow, but I don't want to start fiddling without a plan as that's how I ended up in this mess in the first place...

Roughly how many revs should I be aiming for at tickover, and with the choke pulled out by a quarter of an inch for fast idling?

[kennatt]

you don't need the choke other than for starting,once running ,at this time of year a few hundred yards.push it right in. without a rev counter ,(Have you one fitted,not standard) its just done by ear,turn it down until you feel that its going to stall,turn it up gradually,and then get in and press clutch down to load the engine and see if the revs drop to the point where its going to stall,if so lift the revs again and repeat until with the clutch down the engine sounds ok with a regular steady beat. You will never get the mixture,or timing anywhere near with the revs at that speed.Turn the revs down,screw the nut on the carb right in take it back out 12 flats,then do the lift pin test,speeds up and holds too rich slight turn in,stops too weak slight turn out,revs rise and then fall back and engine revs falter up and down slightly basic starting point for further adjustment once timing is sorted.I have found the easiest way to get the timing near,assuming all other components are ok.slightly slacken the dizzy clamp so it can be moved but still held move it slowly back and forth and listen to the revs they will go up and down as the timing changes. Once you have the highest revs,Alter the idling speed and take it for a run and listen for pinking,if none advance the dizzy untill it does pink then retard bit by bit it to get rid of the noise. Then tighten the clamp. You are then somewhere near,repeat near, the optimum settings ,you can then twiddle about with mixture and timing to get the best performance. Good luck

[Napoleon Boot]

you don't need the choke other than for starting,once running ,at this time of year a few hundred yards.push it right in. without a rev counter ,(Have you one fitted,not standard) its just done by ear,turn it down until you feel that its going to stall,turn it up gradually,and then get in and press clutch down to load the engine and see if the revs drop to the point where its going to stall,if so lift the revs again and repeat until with the clutch down the engine sounds ok with a regular steady beat. You will never get the mixture,or timing anywhere near with the revs at that speed.Turn the revs down,screw the nut on the carb right in take it back out 12 flats,then do the lift pin test,speeds up and holds too rich slight turn in,stops too weak slight turn out,revs rise and then fall back and engine revs falter up and down slightly basic starting point for further adjustment once timing is sorted.I have found the easiest way to get the timing near,assuming all other components are ok.slightly slacken the dizzy clamp so it can be moved but still held move it slowly back and forth and listen to the revs they will go up and down as the timing changes. Once you have the highest revs,Alter the idling speed and take it for a run and listen for pinking,if none advance the dizzy untill it does pink then retard bit by bit it to get rid of the noise. Then tighten the clamp. You are then somewhere near,repeat near, the optimum settings ,you can then twiddle about with mixture and timing to get the best performance. Good luck

Thanks Kennatt, that's exactly the step by step guidance I needed! Will have a go after I've finished working. I do have a rev counter fitted - roughly what is usual at tickover, just to give me an idea? The revs have been high since I got the car, would be great if it didn't sound like a jet aircraft taking off every time I start up! I have a timing light on it's way so I'll be able to get the timing accurate once roughly adjusted.

[Napoleon Boot]

Well I loosened the throttle adjusting screw until it was just clear of the throttle lever with the throttle closed, then tightened one and a half turns (as per this manual: http://tr4a.weebly.com/uploads/2/1/9/8/ ... vicing.pdf), then advanced the distributor by turning the body clockwise slightly. The revs were much more reasonable, I checked the mixture with the lift pin, then adjusted the timing until the engine was running best, repeat, repeat. The lowest I can get it to idle with a healthy sounding beat is about 1,000 revs at idle, but when my timing light arrives I should be able to fine tune this and hopefully get the revs lower.

At one point the engine was starting and running at 600 revs which is the lowest I've ever managed, lovely and quiet but the exhaust was a bit uneven so I had to advance the timing which brought the revs up. I'm optimistic that I'll get there though!

Went for a run around the block up and down hill, the power has returned and no smell of petrol. Thanks everyone for the help and advice, and for your patience as ever!

Seb

[kennatt]

well done, every fault sorted is another set of information stored ,and a great deal of self satisfaction,you could have stuck the car in to a dealer and paid a small fortune,I know a guy who has so little inclination to even change a flat tyre that he doses even know where the wheel brace and jack are. More money than sense. Good luck

[Napoleon Boot]

well done, every fault sorted is another set of information stored ,and a great deal of self satisfaction,you could have stuck the car in to a dealer and paid a small fortune,I know a guy who has so little inclination to even change a flat tyre that he doses even know where the wheel brace and jack are. More money than sense. Good luck

Thank you! It does feel like I've worked my way round most of the car now - I wonder what will go wrong next?
It's all a learning experience, glad to have unraveled one more of the Minor's mysteries...

Seb