Dynastart struggles to turn.

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heinkeljb
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Location: Lewes, East Sussex - UK

Dynastart struggles to turn.

Post by heinkeljb »

Electrical woes have hit Lurch big time! First it was a sticking solenoid. I took that to pieces and cleaned / reassembled (detailed in another thread). But I think because of the sticking solenoid, it has done some damage to the Dynastart.

So I took that off today and the wires to the brushes show signs of having been very hot at some point. Cleaned things up and reassembled whilst I wait for some new brushes from Haflinger Tecchik. It still does not seem to turn the engine over very fast, although I know it will only go at a certain speed even if it is 100% correct.

The real test will be when it is very cold like the other morning when we had a hard frost. It would act like it had a flat battery although it was new and fully charged.

The two books (repair manual and handbook) are both really vague about how you are supposed to check the brushes. I will have to buy one of those "snake cams" so I can see the brushes having only taken off the covering band, but even that you have to take a couple of wires off before you can remove it!

I am also not very enthralled by the use of two little pegs which locate the Dynastart motor and the dynastart fan. They are critical to engine timing and so ought to be a bit more substantial. A little bit of "chattering" due to a loose band and your engine timing will be difficult to set correctly.

John
Haflinger 703AP LWB 1973 - (Once owned by Lady Sutherland & Sons.) Now called "Lurch" !

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Markus
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Re: Dynastart struggles to turn.

Post by Markus »

I would say the wires you mentioned are as you said damaged from the sticking solenoid.

Have a look online for DC electrical motor overhaul. This should detail how to check and clean the contact surface on the arbor.
I would also check that the v belt isn't too tight as this can also cause the dynastarter to struggle.

Those two little pegs or dowels on the dynastart housing play no role in the engines timing. They are there to locate the housing to the driven pullies.

The engine timing comes from the distributor cams.


Let us know how you go.
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heinkeljb
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Re: Dynastart struggles to turn.

Post by heinkeljb »

I beg to differ Markus,

The fan housing has an engine timing mark on it which is what yo use to get the static timing correct. So you then can use a stobe to check that the timing advances the correct amount based on the mark on the pulley wheel AND the mark on the fan housing. So if the peg does not line up, then the mark is in the wrong place which mean the timing is in the wrong place.

During previous ownership, someone has not been kind to the peg under the fan housing on Lurch and it does not look as good as it could in terms of being straight etc. I have put the fan housing in with the mark as vertical as I can. Luckily, I have not touched the timing since I set it up last year and it has been running OK with that.

I was just commenting on the fact that the peg is very small and could have been made more robustly.

John
Haflinger 703AP LWB 1973 - (Once owned by Lady Sutherland & Sons.) Now called "Lurch" !

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Markus
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Re: Dynastart struggles to turn.

Post by Markus »

Ahh yes. I forgot about that mark for the timing strobe. I stand corrected.

I sadly have not seen my Haflinger in 1 1/2 years and its getting a little vague.


Regards,
Markus
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