engine runs on the muffs but not in the water?

anybody have any idea what would cause this? I can run it in the driveway all day, but today when i took it to the lake it would not start. pulled the boat and it fired right up. what gives? its a 1970 60hp evinrude. thanks for any input

Re: engine runs on the muffs but not in the water?

Are you saying you pulled the boat home or started it with a rope?

is the starter engaging?

Re: engine runs on the muffs but not in the water?

If it wouldn't start in the water it could have compression or spark probs. Check those first before going any further.

Re: engine runs on the muffs but not in the water?

The information you give is a little confusing. How is the charge in the battery? Is there enough power to turn it over, if not, it would start with a rope. More info is needed. There is also a fuse near the power head?

Re: engine runs on the muffs but not in the water?

yes the starter is engaging and the battery is fully charged. i when i took the boat out of the water it started right up.just not when its in the water

Re: engine runs on the muffs but not in the water?

(Engine Won't Start or Hard Starting In Water)
(Joe Reeves)

The Evinrude and Johnson engines, starting in 1973, have what is called Magneto Capacitance Discharge ignition, self contained, not dependent on battery voltage. The engine must turn over at least 300 rpms in order for the flywheel magnets rotating past the stator ignition generating coils to supply approximately 300v AC to the powerpack(s), which in turn is needed to supply power to the coils etc etc (spark).

In the water, exhaust back pressure is encountered due to the fact that the exhaust housing (housing between the powerhead and the lower unit) is filled with water. This would drag down the needed rpms, affecting ignition.

Normally the clue to this type problem is that the engine starts fine on a flushette (hose), but is very difficult to start when in the water.

Should this be the case, check the battery, clean and tighten all conections (use a wrench or pliers, not your fingers). Any cable that gets overly warm or hot indicates either a loose, or tight but dirty, or internally corroded cable. And of course check the starter itself.

Re: engine runs on the muffs but not in the water?

Also, check the coil itself. These issues arise when something is leaking. The humidity level on the lake will make electronics more capable of leaking (arcing out) than they will in the driveway. I would suggest dismantling the magneto and thoroughly cleaning it up and make sure nothing is grounding out.

Re: engine runs on the muffs but not in the water?

I believe he said it's a 1970 60hp. That is battery cd not mag cd.

Re: engine runs on the muffs but not in the water?

Whatever the case may be. Problematic electronics will arc out on the water, because of the high humidity versus the driveway. I have experienced this issue with various motors, older and later.

Re: engine runs on the muffs but not in the water?

Boobie.... Oops, yeh and I knew that too (Battery Capacitance Discharge instead of Magneto Capacitance Discharge). I wasn't watching what I was doing and copied/pasted a wrong entry from my database. My mind was thinking about a drop in rpms due to exhaust back pressure in the exhaust housing which somehow affects both ignition systems but I can't recall why it affected the Battery CD setup. I'll see if I can find it.