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+--- Thread: Slight kick back on the starting handle (/showthread.php?tid=3194)
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Slight kick back on the starting handle - John Mason - 10-08-2019
Kl'LI recently had occasion to to remove the distributor on my Ruby which obviously meant I had ti re time the ignition. This I did using the 1/4 marking on the flywheel to establish TDC on no1 cylinder. Then adjusted the dizzy with the aid of a bulb fixed between the low tension and Earth. I started the engine then fine tuned things by ear until the engine ran and sounded smooth. The car now runs and starts well however when starting on the handle there is quite a kick back from compression not because the engine has fired. This is until you get past TDC. IS THIS NORMAL.
John Mason.
RE: Slight kick back on the starting handle - Robert Leigh - 10-08-2019
It sounds as though it is firing as you approach tdc. In my experience when a Ruby type engine is running well you probably will have this situation if turning the handle slowly. When you swing it briskly on the handle it will not be noticeable unless you have it over-advanced. The sound of the engine running will probably be rougher in that situation. Smooth running is always preferable. By blipping the throttle as you adjust the timing you should be able to judge the right setting.
Robert Leigh
RE: Slight kick back on the starting handle - John Mason - 10-08-2019
Thanks Robert. The distributor runs clockwise on my car which way do I turn it to retard the engine. I can mark the pointer on the dizzy try retarding it but if it upsets the sweet running move it back to the mark.
John Mason
RE: Slight kick back on the starting handle - David Stepney - 10-08-2019
To retard the timing, one turns the distributor in the direction of travel i.e. clockwise for an Austin 7. On manual advance cars, setting the timing to approximately 20 degrees full advance usually makes the spark at full retard after TDC. With Rubys, the advance curve is quite limited (8 degrees I believe, so, if you get the engine running at its best, it may very well run slightly before TDC at tickover. If the car is running well, then I should not be worried if it kicks back slightly when cranking it by hand. Just keep you thumb on the same side of the handle as your fingers when cranking it!
RE: Slight kick back on the starting handle - Colin Morgan - 10-08-2019
This is, as best as I can remember, a repeat of the post I put on here yesterday evening that apparently disappeared: The kick occurs when a cylinder fires. My timing is set so that when I turn the engine over slowly there is a small kick each time a plug fires - I think the kick is slight because the compression remains low as the rings and valve guides are worn. If the handle is pulled quickly through half a turn, this generates enough compression and it fires. Once, when setting the timing and getting it too advanced, on starting the engine it gave a severe kick that pulled the handle out of my hand - so that is to be avoided. As you know, the other force felt when turning the handle is the compression - on a tight unworn engine this is significant and makes it hard to rotate the engine smoothly by hand - on such an engine it would presumably be more risky to set the timing very close to the limit? Despite the lack of obvious compression, once running, the Ruby engine provides sufficient power for normal use.
Colin
RE: Slight kick back on the starting handle - Chris KC - 10-08-2019
The starting handle needs a business-like flick with, as others have said, your thumb kept on the driving side of the handle.
Just to spare all from later confusion, may I politely point out that on pre-war distributors, direction of rotation is formally quoted from the drive side - A7 distributors are anti-clockwise units, even though they rotate clockwise as viewed from the cap.
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RE: Slight kick back on the starting handle - Colin Morgan - 10-08-2019
As hopefully anyone using a starting handle has worked out, the handle has to be able to escape from your hand without any fingers or thumb being dragged with it. The kickback occurs very rapidly with no warning - when it did it to me I did not understand what had happened at first.
On a vintage Seven I bought with the magneto replaced with a coil and Ruby distributor driven from the magneto drive, the distributor rotated the wrong way. It would fire and tickover - but, as the mechanical advance was working the wrong way, it would not run properly on the road. If you had asked me which way a Ruby distributor goes, I would have said 'clockwise' - it is useful to know the distinction.
RE: Slight kick back on the starting handle - Bob Culver - 10-08-2019
Apart from a supplementary one recently inherited, the 4 cars (incl 2 Sevens) I have owned down the ages have all had crank handles. On a myriad occasions after stoning the points I have reset ignition by turning the handle with the HT lead laid to produce a spark and listening for the crack whilst watching the marks. It has never occurred to me to otherwise slow crank the engine switched on!
Tend to think that either cyl fires or not but apparently without turbulence etc a very slow and feeble burn can result.
Eons ago an employer had a Fordson truck which seemed to often need cranking. It had a formidable kick back and the cause was a mystery at the time. I have found lawnmowers with wrong advance also kick back. Several causes; an abrupt stop can cause the flywheel to rotate forward.
For decades one car with vac advance was hard to start and eroded distr studs. Eventually the rotor punctured. It transpired that for reasons never entirely fathomed it was firing beyond the end of the rotor.
RE: Slight kick back on the starting handle - Robert Leigh - 11-08-2019
Back in the the 1950s I ran a decrepit two stroke motorcycle. On one occasion it started but did not sound right. On letting in the clutch it began to move backwards, which explained the abnormal exhaust note! This ability of the two stroke to run in either rotation was used on early Messerschmitt bubble cars, which had two contact breakers to allow the engine to be run in either direction, eliminating the need for a reverse gear.
Robert Leigh
RE: Slight kick back on the starting handle - Peter Sweeney - 11-08-2019
I used to drive an 1898 Panhard converted from hot tube to trembler coils. If you tried to start that too advanced it would kick back so fast the handle would rap your knuckles. You never made that mistake twice.