No start, weak spark, lots of gas

Marpet

Cadet
Joined
Aug 10, 2009
Messages
17
1995 rinker 180, 3ltr merc, alpha 1

I have searched the links and found all the suggestions for self diagnosis, which I will be performing shortly, but was wondering if this could be an issue.

First, the story. Have used the boat as recently as 4 days ago with no starting issues, either hot or cold. New battery and even swapped out for another new battery, so thats not the problem. Put the boat in the water 2 days ago and no start. Turned over fine, with adequate rpm (to what it had before), flooded the engine. Let it sit, throttle wide open, etc, still no go. Pulled plugs, dried, looked good, checked connections, pulled dizzy (fun doing that with a pocket knife:rolleyes:, time to build a toolkit), lots of corrosion, no track marks. Cleaned electrodes and rotor, pulled module to check if grounds were rusted. Still no go. There is a spark on all plugs but weak and erratic. Will do the testing of the components to see if thats the problem but this brings me to my question.

I replaced the tach between runnings. I set the switch on the back of the tach to 4c as this is what I have and can't see any other logical setting on the back. The tach is the same as the one I pulled, just 0-7000 instead of 0-6000.
Can't see how that would make a difference. Could having the incorrect setting somehow cause this? Could it cause the failure of one of the components? I pulled the leads of the tach to see if that was the problem but still no go, but maybe the damage was already done.

As I said, I will be doing all the testing shortly but curious why it failed in the first place. Maybe it was just time, after all, looking at the dizzy screws, I don't think it was ever removed before. Still glossy black paint on the screw heads.

Great forum, guys. Keep up the good work.

Gord
 

jtybt

Senior Chief Petty Officer
Joined
Aug 5, 2009
Messages
730
Re: No start, weak spark, lots of gas

Check if spark is hot at coil wire. May be losing spark going thru the dist/rotor and cap. Listen for spark leak.

What ignition system?
 

Marpet

Cadet
Joined
Aug 10, 2009
Messages
17
Re: No start, weak spark, lots of gas

EST ignition.

How would I check for hot spark at coil?

Worked on it for 4 hours and didn't notice anything out of the ordinary. Although, I'm fairly new to this, so learning as I go.

Will post the results when I get a chance.

Gord
 

jtybt

Senior Chief Petty Officer
Joined
Aug 5, 2009
Messages
730
Re: No start, weak spark, lots of gas

Run the center coil(spark plug) wire on an old spark plug and touch it to ground to check the quality of the spark as you try to start the engine.
 

fat fanny

Lieutenant Commander
Joined
Feb 9, 2006
Messages
1,935
Re: No start, weak spark, lots of gas

Good tip jtybt. You could also try turning it over in the dark and look for a short somewhere light blue arc also if your certain of a weak spark try all electrical connections and even the springs in the dizzy as well as a weak coil but try a continuity test on all plug and coil wires (wiggle while doing it) I have also experienced a small crack in the dizzy cap causing weak spark and the est ignition you must be certain to seat the dizzy cap just right into it's notches especially if you didn't see any track marks from the rotor on the pick ups and make sure you have all the wires routed from the cap to the plugs correctly then try a new set of plugs nothing to lose it's always good to have a set of spares on board. If you end up buying a new module make sure you don't scrimp and buy aftermarket buy OEM Delco only or your just wasting money and time. Good luck! and post back
 

Marpet

Cadet
Joined
Aug 10, 2009
Messages
17
Re: No start, weak spark, lots of gas

Well, got at the boat today to see if I could pinpoint the problem, and apparently the problem was holding the key:D

Boat ran great on Tuesday last week. INSTALLED NEW TACH ON FRIDAY (that becomes key later). Boat wont run on Saturday. Weak spark, plenty of gas, no go. Tried again Sunday but gave up and took the boat home. Disconnected the Tach in the driveway just to see but still no go. Rechecked the spark tonite and nice and strong, bright white and stable (?). Hooked everything back up, put on the muffs, regapped the plugs, flooded engine starting procedure, fired right up!:redface: Crawled under the dash, hooked up the ignition wire, ground and as soon as I touched the sender wire to the terminal, got a spark and the engine stumbled. Shut off engine and hooked up wires, engine wont start, disconnected tach, fired right up. Went and got the old tach, ign and sender terminals on opposite sides:eek: All that for two crossed wires:redface:

Time spent working on a boat that wants to run - 4 hours
family members pissed that it wont - 4
brand new tach - $70
another brand new tach to replace the fried brand new tach -$70
not taking the time to compare the back of the tachs - priceless

Lessons learned.

1. There is no substitute to a well stocked toolkit.
2. However unlikely, start with the recent changes first.
3. Always compare replacement parts.
4. There is no substitute to a well stocked toolkit.

Thanks for your help, guys. I hope we all can learn from this mistake.

Gord
 
Top