Mike Sharpe Posted April 8, 2015 Share Posted April 8, 2015 Once turning switch on. When pressing foot switch to turn on starter, the starter sound of turning over sounds sluggish and the hotter the engine the harder it seams to turn. I have put a starter heat insulator sheet between the starter motor and the engine wrapping the starter motor. I have a 6 volt system and it is a new starter motor, sounds as if it needs more amps if this helps my description of the problem. I look forward to any help on this, thank you. Quote Link to comment Share on other sites More sharing options...
arcot1751 Posted April 8, 2015 Share Posted April 8, 2015 This could be an earthing problem, check all earth leads to body/chassis removing and cleaning them to ensure a good connection. Have you got the right battery for the job ? Is the actual starter switch getting hot ? Another thing is, are the Earth leads 6v items, because 6v leads are much thicker than 12v ones, many starting problems with 6v systems occur when people use incorrect leads. When I bought my jeep it turned over very slowly, I was at the point of changing to 12v when I stumbled across an American website which stressed that any 6v vehicle should turn over properly IF it has PROPER 6v wiring. I changed to 6v leads and problem solved My jeep starts better than many 12v converted jeeps now and since then I have sorted several others with the same problem merely by fitting the CORRECT leads. Good Luck. Quote Link to comment Share on other sites More sharing options...
Sean N Posted April 8, 2015 Share Posted April 8, 2015 (edited) Mike, presumably this is a known good engine that has been starting OK in the past, rather than a new rebuild? If a new rebuild, it could be that the engine is tight. If a known good starter, and assuming your description is as accurate as it sounds, you're looking for losses in the electrical system. Check all the connections and try turning it over a bit, then carefully have a feel of the starter switch, all the connections and the starter itself to see if anything's getting hot. Wherever it's hottest there's likely to be a high resistance, i.e. poor wiring, bad connection etc. Clean up any connections, replace any suspect parts and try again. Don't forget to check all the earths - engine, chassis, battery etc. Another point - has there been any rewiring? Low voltage electrics draw more current for a given power, so will need larger cabling; if it's been rewired has cabling to suit a 6V system been used? Also don't assume the starter is good just because it's new; if it's NOS it might have corrosion internally due to condensation, if rebuilt it may not have been rebuilt properly. Finally is the battery OK? Edit - sorry for the echo, Arcot, we posted at the same time! Edited April 8, 2015 by Sean N Echo Quote Link to comment Share on other sites More sharing options...
mtskull Posted April 8, 2015 Share Posted April 8, 2015 (edited) This could be an earthing problem, check all earth leads to body/chassis removing and cleaning them to ensure a good connection. Have you got the right battery for the job ? Is the actual starter switch getting hot ? Another thing is, are the Earth leads 6v items, because 6v leads are much thicker than 12v ones, many starting problems with 6v systems occur when people use incorrect leads. Sounds very much like an earthing problem to me and it is very easy to check: connect a voltmeter between the engine and the battery earth terminal and observe the reading when the starter is operated; this indicates if there is a voltage drop across your earth leads. Basically, any reading at all indicates a problem. If you don't have access to a voltmeter a quick and easy way to check the earth is to connect a jump lead between the engine and the battery earth and see if there is any improvement. Sorting out earthing problems is not always a matter of making sure that the connections are clean, either: I have seen quite a number of vehicles where the braided earth straps have corroded and it is surprising how much resistance can build up in them. For the cost of a couple of earth straps, it is probably worth replacing them anyway if they are more than a couple of years old. Edited April 8, 2015 by mtskull Quote Link to comment Share on other sites More sharing options...
Tony B Posted April 8, 2015 Share Posted April 8, 2015 Having a 6 volt WC54 I know what you mean. I can only reiterate what has been said . Clean all contacts, a second earth lead can solve a lot of problems. I now use exclusivley toothed washers on all the fittings. As DC current runs IN the wire rather than ON it as AC does, basic rule, twice the thickness of 12 volt wire to allow for twice the amps. You don't state which vehicle, but check the contactors on the switch are fitting in properly. Quote Link to comment Share on other sites More sharing options...
mtskull Posted April 8, 2015 Share Posted April 8, 2015 (edited) Have you got the right battery for the job ? Even if your battery is brand new, checking the battery specification is worthwhile. Many people make the assumption that if a battery has the correct Amp Hour rating then it will be OK but this is only half the story; you also need a battery that will deliver sufficient Cold Cranking Amps. Think of the battery as a bottle: the AH rating refers to the capacity of the bottle i.e. How much it will hold, whilst the CCA rating refers to the size of the opening; i.e. it is a measure of how fast it can deliver its contents. A pal of mine once fitted a Reliant Robin battery to a Laverda Jota motorcycle (against all advice), on the basis that they had the same AH capacity and, in his view, "a battery's a battery". He very soon became adept at bump starting a Laverda... Edited April 8, 2015 by mtskull Quote Link to comment Share on other sites More sharing options...
101 Ron Posted April 8, 2015 Share Posted April 8, 2015 If it is a Jeep..........a new starter,battery or cables will not help you if the bush in the bell housing has not been replaced. The bush may look good ,but if slightly worn will cause what ever starter is fitted to pole out and draw excessive current and crank the engine over slow as well as leaving little voltage left for a good spark. Quote Link to comment Share on other sites More sharing options...
Mike Sharpe Posted April 8, 2015 Author Share Posted April 8, 2015 Yes it is a jeep 1942 Willys MB, 6 volts. I appreciate all the advice and will look into your suggestions. Thanks. Quote Link to comment Share on other sites More sharing options...
R Cubed Posted April 8, 2015 Share Posted April 8, 2015 Dont forget you can use Vaseline ( petroleum jelly ) on all battery cable ends and on the connections on the batteries, I use it on all the joints especially the straps to chassis rails, make sure all paint removed down to bright shiny metal apply good splodge of Vaseline and bolt up tight wipe off excess and paint over. Has worked for me for years and years on all my vehicles, and a bonus you can undo them if you need to. Quote Link to comment Share on other sites More sharing options...
Mike Sharpe Posted April 9, 2015 Author Share Posted April 9, 2015 Again I appreciate all the help and enjoy this site very much. One further question is if it is bad grounding then why is it a lot worse when the engine has been driven for 20-30 mins and has got hot, to start it up again? Quote Link to comment Share on other sites More sharing options...
Tony B Posted April 9, 2015 Share Posted April 9, 2015 Again I appreciate all the help and enjoy this site very much. One further question is if it is bad grounding then why is it a lot worse when the engine has been driven for 20-30 mins and has got hot, to start it up again? Earths are a funny *&^^% of a thing. The vehicle can start ten times out of ten, then completly dead, as happned to me last year. The vehicle can start when cold as the earth is tight and cold, then heat causes expansion, vibration loosens the earth. Also as metal heats a general rule the resistance of the wire increases. More resitance means current drop. With 6 volt you need twice the ampage (Couloumbs, (the amount of electrons) moving per second) to get the same Wattge (Power) as a 12 volt. So your starter could well be giving less power. Rule is Volts X amps = Watts Quote Link to comment Share on other sites More sharing options...
deadline Posted April 10, 2015 Share Posted April 10, 2015 Don't forget to clean the commutator with commutator stones. Commutator's are copper and will oxidize causing high resistance. The stones powder will also clean the brushes to ensure good contact. If your jeep is a daily driver the constant starting will keep the commutator clean... but if it sits more than it runs then the oxide will build up and slow the motor. Here is how to do it with before and after photos https://www.tm9-801.com/forums/viewtopic.php?f=3&t=739&p=1624&hilit=commutator#p1624 Do not use sand paper!!!! Quote Link to comment Share on other sites More sharing options...
Mike Sharpe Posted April 13, 2015 Author Share Posted April 13, 2015 Want to let you know that I have solved the problem it was an earthing issue. I appreciate all of you that replied, thank you. Quote Link to comment Share on other sites More sharing options...
Sean N Posted April 13, 2015 Share Posted April 13, 2015 Well done Mike, it did sound as though it might be. Quote Link to comment Share on other sites More sharing options...
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