1987 Mercruiser 470 starting problem

[fdavanzo]

I have a pair of Mercruiser 180's in my 1987 Grady White 25. I just recently purchased the boat which had no problems with it's survey. Both engines start fine when cold. Once they're warm they barely crank over, even if I switch the battery switches for both batteries. I thought the batteries were the problem so I replaced them with 1000 amp cranking batteries. Still have the problem although the stbd engine will start sometimes when it's hot. The stbd. engine appears to have a "New" starter on it but it still doesn't start all the time. Once they atart they run great, even the charging systems are functioning properly. Can this be caused by improper ignition timing or is it more likely a starter issue. Also, what is the proper operating temp for these engines??

Thank you,
Frank Davanzo

 

[jerryjerry05]

Re: 1987 Mercruiser 470 starting problem

Sounds like the starters are dragging.What condition are the cable connections?Sometimes the older thin cables will cause problems.Anything smaller than #2 might cause problems. Most Mercruiser run anywhere from 160 -180.
Do good tune-up as sop.Jerry

 

[fdavanzo]

Re: 1987 Mercruiser 470 starting problem

Hi, What do you mean by "dragging"? All the wiring appears to have been professionally replaced when the boat was repowered in 2004. The wiring is all #2 Gauge. I have seen many posts around the web regarding starting problems but I haven't really found any answers. If these engines are prone to starting problems, I would think mercruiser or someone would have fixed the problem by now. Are there different starter manufacturers or different starter designs for these engines?? My starters are the later design with the integral solenoid. I'm not sure of the manufacturer though..... Any ideas??

Thank you,
Frank

 

[ne7800]

Re: 1987 Mercruiser 470 starting problem

not sure about the starting problem but i have 1 470 in my 18' four winns ran it for 3 hours last weekend on the river and lake and it ran around 145-155 i did however just replace the thermostat

 

[CAPTKEV85]

Re: 1987 Mercruiser 470 starting problem

Start off at the basics, check all connections. make sure there tight and no corrosion. if the batteries are new and they can crank the starter over, u might have a starter issue. My 470 was the old style with seperate soliniod. when the motor was hot the starter wouldnt crank. turned out the starter was bad. good thing was my starter was only 120.00 pretty cheap for marine starter.