Fuel spill

[micmak]

35 minutes ago, Pete Lewis said:

you can balance the throttles mechanically without any special tools , as was done at the factory in the day

loosen one of the coupling clamps 

back off the idle screw and turn in to just !!!   touch the casting  wind it in 1.5 turns

do this on both then retighten the coupling clamp 

if the idle is too fast back off both screws equal amounts 

this just sets both throttle plates in the same basic position 

if you noticed a small drop in idle with filters on then its a a little weak 

really  all you need to do with the jet adjuster is turn it to get the best fastest idle

somewhere between sputter being weak  and wooly going too rich 

you ears will tell you 

Pete

 

I love your descriptive words, Pete; Wooly and Sputter! 

When you say loosen one of the coupling clamps, I presume you mean the linkage joining the operation of the two carbs? Sort of separate them from each other?

[Pete Lewis]

dont need to disconnect or remove just loosen

Pete

[micmak]

I didn’t DO anything to the car today, but I was curious to see how it would start after yesterday’s carb reassembly and re-tuning.   It needed a FULL choke to fire, but I was immediately able to push it in to a comfortable high idle.  It did idle a little lumpy, but it is a cold day and the car is sitting in an uninsulated garage.   I was pleased enough, so I turned it off.  

It got me thinking back to my childhood.  My Mother always had a procedure for turning off the car.  She used to rev up the car once, and as it died down, she’d turn the key to kill it.  I remember a lot of neighbors doing the same thing when I was a kid.  Is that the proper, or accepted way to turn off a car from the 1960s?

 

I have another question about wheel geometry, but I’ll start a new thread for that.

.....Mick.....

[Pete Lewis]

well from my background    its a No its just a waste of fuel and does nothing apart from leaving the cylinders charged with petrol to wash the oil from the bores 

Pete

[Iain T]

No fuel leak? 

As to turning engine off I let it idle then switch off. 

Iain 

[micmak]

1 hour ago, Iain T said:

No fuel leak? 

As to turning engine off I let it idle then switch off. 

Iain 

No fuel leak, Iain.  Admittedly, I didn't run it long enough to warm up and run without the choke, so it was not any suitable test for the leak problem.  As soon as this cold spell passes, I will take it out for a drive and hopefully that will test it for the leak/fuel dump.

And I think I will continue with my shut-down procedure that I have used all my life:  just turn it off!!!   No revving up beforehand, no nothing.  Just turn the key! 😁

.....Mick.....

[Pete Lewis]

51 minutes ago, micmak said:

no nothing.  Just turn the key! 

thats a sensible plan 

Pete

[micmak]

I'd like to know why so many drivers from my childhood revved up and then turned off the engine as the revs died.  What was their reasoning?  There must have been some recommendation or direction from car manufacturers for so many drivers to adopt this habit.  

.....Mick.....

[johny]

All I can think is that this was a way of ensuring the float chambers were full before stopping the engine. This then meant there was still fuel in them for the next restart so reducing the chance your battery might die before fuel got pumped through. These days our cars are pampered so the starting conditions are less arduous plus the batteries newer and modern...

[Iain T]

2 hours ago, micmak said:

I'd like to know why so many drivers from my childhood revved up and then turned off the engine as the revs died.

Annoy the neighbours! 

 

Edited December 1, 2023 by Iain T

[micmak]

12 hours ago, Iain T said:

Annoy the neighbours! 

 

Ha ha, well, they succeeded!

[micmak]

On 30/11/2023 at 18:09, Pete Lewis said:

you can balance the throttles mechanically without any special tools , as was done at the factory in the day

loosen one of the coupling clamps 

back off the idle screw and turn in to just !!!   touch the casting  wind it in 1.5 turns

do this on both then retighten the coupling clamp 

if the idle is too fast back off both screws equal amounts 

this just sets both throttle plates in the same basic position 

if you noticed a small drop in idle with filters on then its a a little weak 

really  all you need to do with the jet adjuster is turn it to get the best fastest idle

somewhere between sputter being weak  and wooly going too rich 

you ears will tell you 

Pete

Hi Guys, well today was not as bitterly cold as recent times, so I went out to the car.  I loosened the coupling clamp between the carbs and I adjusted the idle screws as Pete described and retightened it.  I was happy that the carbs looked equal.  I started the car.  It started perfectly and I was able to reduce the choke to a nice comfortable high -but not too high- idle.  It warmed up nicely and idled perfectly with no choke.  Then I realized that when I revved up the car, it didn’t return to the same idle:  it remained a little higher.  I noticed that the idle screws were not actually touching the casting at all.  I was able to push them back by hand to lower the idle.  I played around with the coupling clamp a few times to readjust, and finally I was comfortable with the idle and the level it returned to after revving up.  The car idled so nicely.  I didn’t drive the car, but after about 20 or 25 minutes of running, I was pleased with the idle and the general sound.  I might take it for a drive tomorrow, I’ll see. 

[Pete Lewis]

the screw that contacts the choke fast idle cam Must have a small gap at idle/choke off,

or it will hold the idle open .

Pete

[Colin Lindsay]

On 01/12/2023 at 19:00, micmak said:

I'd like to know why so many drivers from my childhood revved up and then turned off the engine as the revs died.  What was their reasoning?  There must have been some recommendation or direction from car manufacturers for so many drivers to adopt this habit.  

.....Mick.....

Possibly something to do with running on due to sooty plugs and contaminated chambers. I can remember cars that ran on for literally minutes after the ignition was turned off due to contaminants igniting in the engine. It may have washed out the cylinders, but then: why did the fuel not ignite? Unless the excess put out the sparks in the chamber... I must do a bit of research for curiosity.

[Iain T]

17 hours ago, micmak said:

I noticed that the idle screws were not actually touching the casting at all.

Do you mean the throttle stop screw on each carb? 

I would screw in the fast idle screw (choke) to give it clearance and get it out the way of the cam then balance the carbs by loosening off the throttle connector and screw in the throttle stops the same amount. Tighten the connector then screw out the fast idle to around 2-3mm gap to the cam. I don't know your throttle cable arrangement but if it has a nipple on the end ensure it's fully seated or your idle will be higher. 

Then give it an Italian tune up at Khan's 20mph.....! Oops sorry you're in Dublin so 30mph?

Iain 

Edited December 10, 2023 by Iain T

[micmak]

On 10/12/2023 at 11:15, Iain T said:

Do you mean the throttle stop screw on each carb? 

I would screw in the fast idle screw (choke) to give it clearance and get it out the way of the cam then balance the carbs by loosening off the throttle connector and screw in the throttle stops the same amount. Tighten the connector then screw out the fast idle to around 2-3mm gap to the cam. I don't know your throttle cable arrangement but if it has a nipple on the end ensure it's fully seated or your idle will be higher. 

Then give it an Italian tune up at Khan's 20mph.....! Oops sorry you're in Dublin so 30mph?

Iain 

Iain, Yes, I mean the throttle stop screws.  I did as you described to balance the carbs, and the choke screw is well out of the way when warmed up.  The spring on the throttle cable is attached perfectly and it’s strong. But the idle does not want to return to a complete idle when the revs die down.  I can press against any of the idle screws with my finger, and the idle will die down. It’s as if it is stuck, somehow.  But yet, there is nothing stopping the throttle stop screws from returning to their normal resting place.

…..Mick…..

[Iain T]

9 minutes ago, micmak said:

But yet, there is nothing stopping the throttle stop screws from returning to their normal resting place.

It could be that the accelerator cable needs adjusting and is too short. Can you adjust and lengthen the cable at the bracket so that the nipple that fits into the throttle has a little bit of slack and not stopping the throttle from returning properly. This is probably the reason why it doesn't return to the throttle stops. 

In short the throttle is being held back by the accelerator cable. 

An easy fix if I'm right! 

Iain 

Edited December 12, 2023 by Iain T

[Steve P]

Or it can be the butterflies not seating against the carb body when closed, or worn spindles.

S

[Pete Lewis]

apart from its been ok for a while

you can add to the causes having the throttle discs fitted back to front so they cant seal fully

and hoping it doesnt have the nasty poppet valves to weaken on  overrun 

Pete

[Morgana]

On 01/12/2023 at 19:00, micmak said:

I'd like to know why so many drivers from my childhood revved up and then turned off the engine as the revs died.  What was their reasoning?  There must have been some recommendation or direction from car manufacturers for so many drivers to adopt this habit.  

.....Mick.....

I have read in a Yanmar 2GM20 marine diesel manual to rev the motor high, then turn it off (fuel cut-off valve), which is specifically advised instead of turning off after idling. The explanation was to do with removing burnt residues, but then there isn't any fresh fuel coming in as it's been turned off with the valve.

[johny]

This is interesting from the Triumph service training notes manual and shows the acceptable pump pressure range at cranking revs plus the means to reduce it if too high....

[Stratton Jimmer]

Interesting to see how the fuel flow is adjusted. Exactly what I did to the Sixfire when the carbs were flooding.

[Unkel Kunkel]

On 01/12/2023 at 19:00, micmak said:

I'd like to know why so many drivers from my childhood revved up and then turned off the engine as the revs died.  What was their reasoning?  There must have been some recommendation or direction from car manufacturers for so many drivers to adopt this habit.  

.....Mick.....

I have never understood why people did this.

Perhaps there was an idea that the engine draws in an unburnt charge of fuel vapour that might ease the next start.Equally it could be argued that it might degrade the oil film on the cylinder bores..

Perhaps it was just something people did  - some sort of flamboyant gesture, even the with an occasional  back-fire.

In contrast, for a modern engine with a turbo  it is recommended to the  not  to rev and switch off, and even let the engine idle  briefly after a fast run.

The reasoning is that the turbo  continues  to spin (very fast) for a short while after the engine has stopped after such a  ‘ revving ‘.Importantly, the  oil pump will have also stopped and with it the supply to the turbos (very hot) bearings.If adopted as a routine then the life of the turbo  could be reduced.

At the other end of motoring history, some cars had flywheels of considerable mass and it is surprising to see how long they continue to spin over after the ignition is switched off.

 

[PeteH]

On 13/01/2024 at 12:58, Unkel Kunkel said:

contrast, for a modern engine with a turbo  it is recommended to the  not  to rev and switch off, and even let the engine idle  briefly after a fast run.

The reasoning is that the turbo  continues  to spin (very fast) for a short while after the engine has stopped after such a  ‘ revving ‘.Importantly, the  oil pump will have also stopped and with it the supply to the turbos (very hot) bearings.If adopted as a routine then the life of the turbo  could be reduced

Something I have always done. I have been asked by several folk that very question “why”. On the big marine diesels they go as far as having the oil feed to the turbo bearings taken from a tank in the engine room upper gods, itself supplied via the pressurised system. This allows of a supply of oil to the turbo for an extended period of time after the main pumps have been shut off. Some turbochargers can idle for a considerable period. 
 

Pete

[micmak]

Hi Guys, long time no talk.  Today was a really nice day for the first time in weeks. The roads were nice and dry!  I started up the Vitesse for the first time since a week or so before Christmas.  It started perfectly.  I let it sit there on high choke for a while, then gradually pushed the choke in over a 5, 6, or 7-minute period, as you might normally do.  When it was warmed up, it idled very nicely.  So, I went for a drive.  I stopped at the fuel station and again at a local shop.  It started perfectly again at both locations.  It drove very nicely.  And when I got home it still idled nicely, if a little high. It sounds nice and even, and the performance when driving was just perfect.  The round trip was only about 20kms, but still, this is the first time I actually drove the car after several adjustments to the carbs.  I think, I THINK I might have solved my problems.  I am almost afraid to say that out loud, but it really drove and behaved so well.  I might play with the slightly high idle.  Or I might not.  I dunno.  I adjusted the cable a little to try to get the idle down a bit.  I mentioned before that all the idle screws are not touching the castings, so it would imply that the cable needed adjusting.  My adjustment today made little difference.  I might disconnect it and try to spray oil into the cable sheath to lubricate it to see if that will bring down the idle a smidge.  In the meantime, so what if it idles slightly high?  The car runs so well now aside from that very minor annoyance.  

Edited February 16 by micmak