hot start problems

[mr.niceguy]

i'm new here, but this seems like the place with the good info, so here goes it.<br /><br />1979 470. starts fine when cold, but after running for a while, it won't start again. no cranking, no nothing. upon replacing the battery (i always keep an extra freshly charged on board), it will start again. it also seems to start again after cooling off for a half hour or so. other strange symptoms are- stalling out when going from forward to neutral, and reverse to neutral. this happens regardless of whether it has been on the run for awhile or not, and it knocks off the ff/df and vhf so that i have to turn it back on, like all power is being cut somewhere, rather than just the engine from the ignition switch. i have made sure all connections are clean and tight, so that is not the problem. i've heard condenser, coil, throttle switch being thrown around as possibilities, but are my symptoms indicative of a couple problems? thanks for your help, i can't stand being at the dock when the stripers are not.

 

[Don S]

Re: hot start problems

Stalling while shifting is most likely a bad shift cable. When they get stiff they hold the shift interrupt switch too long and allows it to die.<br />Have you checked the charging output while running? If it's not charging and the battery is low that will sure keep it from starting.

 

[mr.niceguy]

Re: hot start problems

it's not a battery problem. maybe the time it takes to switch batteries allows things to cool a bit and that's why it starts, because i've tested the battery when it won't start and it always reads around 13 volts. it just won't engage the starter, like the voltage is in the battery yet can't make its way to the starter when it is hot.

 

[mr.niceguy]

Re: hot start problems

i just checked, and the battery reads 12.7 regardless of whether the engine is running or not.

 

[trog100]

Re: hot start problems

so the charging system isnt working.. it should read higher when the engine is running than when its not running..<br /><br />12.7 volts however does show a reasonably well charged battery.. <br /><br />trog

 

[Dunaruna]

Re: hot start problems

Originally posted by mr.niceguy:<br /> .....i've tested the battery when it won't start and it always reads around 13 volts.....

Remove the terminals at the batt and the connections to the starter & block. Wire brush everything. Reconnect.

 

[Don S]

Re: hot start problems

Doesn't sound like it's charging like it should. The 470's had a stator under the front pulley with a water cooled regulator on the port side of the engine. It really needs to get checked out to find why you aren't charging like is should, but that isn't your problem.<br />Have a look at this post and see if it helps.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012808;p=1#000000

 

[mr.niceguy]

Re: hot start problems

i will print that out, use it, and get back to you. the problem is, i can't duplicate the scenario in which it doesn't start unless i am in a place where it would not behoove me to do so (i.e. out in the bay about to get beached or smashed against the sodbank, she always starts hot when i'm back at the dock after nursing her home, of course). but i'll try it cold and see what happens. you are a good and generous man.

 

[trog100]

Re: hot start problems

something a wee bit wrong here.. he has two batteries he swops about.. it has to be assumed one gets charged off the boat..<br /><br />lets assume he puts a fully charged one on the boat.. his fully charged one reads 12.7 volts which is about right for a battery that has stood for a few hours after coming off charge.. <br /><br />he quickly fires his engine up and still has a reading of 12.7 volts.. this mean that his chargeing system isnt working at all.. period..<br /><br />course if after running for a while and that while is a reasonably long while.. he still gets a reading of 12.7 volts engine running or not.. he has a magical battery that dosnt run down or go flat..<br /><br />what sort of battery is it.. i would like to buy one..<br /><br />as computer folks say.. "garbage in garbage out"..<br /><br />trog

 

[Richard Petersen]

Re: hot start problems

You probably have a badly corroded battery post clamp. Thats why the new battery works at first. Clean both battery clamps till shiney or just replace them. Also check the other ends of the battery cables, could be loose or corroded also. You have main battery cable connection problems.

 

[Laddies]

Re: hot start problems

Usally a starter that don't work well on a warm engine is either timing or the armature is dragging if it don't turn over well pull the coil wire if it turns over then it's timing if it don't get the starter repaired

 

[Don S]

Re: hot start problems

You should also be using a DVM (Digital Volt Meter) or any accurate VOM (Volt Ohm Meter) to test your voltage. If you are using the instrument panel meter, your numbers are basically worthless. About the only thing the dash meter tells you is if it goes up when the engine is started, the alternator is working. What the voltage is, is about as accurate as a boats gas gauge.

 

[mr.niceguy]

Re: hot start problems

i am using a digital voltmeter. i also have already replaced the battery clamps and prettied up all connections. the symptoms continue despite these attempts at a simple remedy. and yes, the battery read 13.6 after taking it off the charger, about an hour and a half later it was put into emergency service, and read 12.7 at the dock after running 4200 rpm for about 1/2 hour, the same reading whether the engine was running or off. how much should the voltage be depleted if the charging system isn't working? isn't it possible that the charging system works until some component heats up enough to malfunction?

 

[Don S]

Re: hot start problems

You need to be checking the voltage on the boat, not in your garage with (and after) a battery charger is on it.<br />Put it in the boat, check the voltage.<br />Then start the engine, and at idle check the voltage.<br />Then raise the rpm up to around 2000 to 3000 rpm and see what the voltage is.<br />If it's all the same or lower than the first check, then you have a charging problem.

 

[Richard Petersen]

Re: hot start problems

Bad, main battery disconnect switch or main battery cables are corroded somewhere under the insulation. You are losing everything at once sometimes. If I did not know better, I would think both batteries are opening up due to vibration ,heat and old age.-------You should get 10 good starts on a fully charged battery. Forget everything else and keep checking the heavy current stuff first.