Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Mercruiser 3.0 won't start

waynej's Avatar

Join Date: Jan 2005
Posts: 8

05-15-06, 10:59 AM   #1  
Mercruiser 3.0 won't start


I have a 1979 Mercruiser 3.0 with Alpha 1. It ran great last summer, but when I pulled it from storage to get it running, it would not start. I had changed the oil and spark plugs prior to trying to start it.

I tried pouring gas down the carb (this usually worked) and it didn't even kick. I pulled a spark plug to check for spark and did not find any, I even tried several different areas to ground. I cleaned the points and distributer (wasn't really dirty) to no avail.

I know my battery is very weak, could this be the problem? I could not find any obvious problems i.e. broken wires, etc.

If anyone has any ideas, I would appreciate it. We are coming to a long weekend here in Canada and it would be nice to have it running by then.



Sponsored Links
Pwrbait's Avatar
Visiting Guest

Posts: n/a

05-25-06, 07:49 PM   #2  
If it is cranking over, you should have some spark, unless it's going so slow it doesn't matter. Charge or replace your battery then try again. If still no spark, start at your coil, cap, rotor...the obvious stuff first. Let us know how it goes.

harveje's Avatar

Join Date: Jan 2006
Posts: 122

06-04-06, 08:41 AM   #3  
If you have to old points system the best ting is to upgrade to electronic ign. This takes about 30 min. and WELL worth it. Try checking voltage at the coil terminals.

TechProf's Avatar

Join Date: May 2007
Posts: 5

05-03-07, 08:42 PM   #4  
Coil Wire to points an issue

Sometimes the wire that goes from the negative side of the coil down to the points inside the distributor gets frayed or worn. If so, you can loose spark and power. So check out that wire.

Also, if you ever replace a distributor cap, mark where the mounting screws came out. I actually had one that was off 180 degrees and that caused the engine not to have good spark or fire at all.

Finally, 12.6 volts is what you want from a good battery test. And you want a real good ground on your negative terminal. You should have one main ground cable goind to your engine block and perhaps a smaller ground wire going to your trim pump. But make sure the ground wires are clean, and are tight on both ends. Good luck

Search this Thread