My Mercury flathead/6V won't start after the winter pause. First the solenoid stays quiet and suddenly it does "klack, klack, klack" like a machine gun but the starter does not move. Is it safe to assume that the solenoid is gone? Is it possible to bypass the solenoid and test if the starter works at all or is this risky?
You may have a bad connection at the battery, solenoid, or the ground. That is usually the cause of a solenoid clacking like that. Or a weak battery.
I bought the battery last year and I recharged it for several hours before I tried starting the car. The display on the battery recharger said that it was 75 % full. I also removed the solenoid today and cleaned all the connections, but it did not help.
If your starter worked fine last year, the odds are your battery is too low or your ground and battery cables are not making solid contact. Check grounds from cab to engine, engine to chassis and chassis to cab. I always run three. Charge that battery to 100%.
If battery is good and solenoid band, typically the starter will crank slowly and spark will be weak due to so much amperage being eaten by the resistance. A diagnostic would be to touch the solenoid...if you immediately smell burning bacon and hear screaming solenoid has too much resistance...Lefty.
I have to admit that the problems already began last autumn when sometimes the solenoid/starter stayed quiet for some moments and only started to work with a delay.
My solenoid always became very hot when trying to start and the starter always cranked slowly, even with a brand new battery. This was a problem since I got a the car. As this is my first 6V car I always thought this is a 6V thing. As a solenoid is much cheaper than a new battery; I will replace the solenoid first and see what happens.
You can test it. Take off the cable that goes down to the starter. Then momentarily, touch that cable eyelet to the opposite side big cable at the solenoid. You then are "jumping the solenoid". If the starter works/engages each time you jump-test it, then either the solenoid is bad, or the wire to starter button, or the button switch is not working correctly. .
What kind of charger are you using? How many amps are you starting out with is a better question. If charged "several hours" and only at 75% it probably needs a day or two longer to cook for a while.
Your battery would be better preserved by being kept charged through storage periods rather than merely charging it when desiring to use it again. The so-called battery tenders or maintainers are the best solution I have found to get the best performance and life expectancy for my batteries during off season storage.
Just an update. Loaded the battery for two days but could not get it over 75 %. Then tried to start the car, but the starter moved only very slowly and then nothing. Asked my battery man if my charger might be the problem but he was sure that it was right/strong enough for this type of battery. So I bought a new battery and the car started immediately. So it really was a battery problem, don't know why it broke down as early as two years. Maybe just bad luck. My last battery held for 15 years. Thanks for all the good advice.