mid 90's E 70 intermittent

My older 70 won't start sometimes, but usually if you go for a drive, cross some speed bumps or something it will fire right up - once on the water it has not failed to start - yet. Took it to local mechanic after trying starting fluid, etc. and he deduced bad switch, said it was hard to get and that it fell apart when he removed cover. Switch was installed used at dealer when boat was purchased 5 years ago, problem slowly gained in frq since then. Started every time after he replaced switch ( used bomber) on his property and when I got home. After two weeks weather is right, tried to start - cranks strong, faint smell of gas, no fire. Starting fluid no help, I really feel electrical fault somewhere. Clues, anyone? TIA

Re: mid 90's E 70 intermittent

unplug the wiring harness, then jump the starter, if it starts, the only way to stop it is the flip the lever on the primer and flood it. or pull the plug wires. this isolates the control box. if it starts it's in the wiring harness of control box.

Re: mid 90's E 70 intermittent

Already did that - guess I didn't use right terms - replaced control box and kill switch, no difference.

Re: mid 90's E 70 intermittent

Oops, just checked with mechanic, says he did NOT replace control box - search here turns up no match for control box - are you referring to the power pack? Thanks

Re: mid 90's E 70 intermittent

check and clean all the connections at the motor as well. Could be a loose or dirty connect that the vibration of the motor is causing to lose connection.

Re: mid 90's E 70 intermittent

tashasdaddy said:

unplug the wiring harness, then jump the starter, if it starts, the only way to stop it is the flip the lever on the primer and flood it. or pull the plug wires.

Click to expand...

Can't you just plug the wiring harness back in??? I have never tried this but I was just thinking that it would allow you to kill it.

Re: mid 90's E 70 intermittent

the control box is the box where the keyswitch is installed in.

need a better description of the symptoms.

When it fails to start: does the starter spin and engage the flywheel? If not, do you hear the solenoid "click"? If not, can you hear the primer solenoid "click" when you push the key in (push-to-choke)?

Re: mid 90's E 70 intermittent

OK, we installed new controls (used) - of course it worked then, but it was intermittent to begin with. It fired 10 or 12 times, brought it home, it fired, - right until I got ready to put it in the water. When it doesn't, the starter kicks in, flywheel turns, all the signs of life except fire. Tried starter fluid, nada, left key in, kill switch on while I web quested for answers, went out later, battery was dead. Charged that, cranks nice, no fire. I am baffled.

Re: mid 90's E 70 intermittent

BTW, it only fails to start after sitting for some days - it has never failed on the water or quit while running.

Re: mid 90's E 70 intermittent

First of all you should use premix in a spray bottle to spray into your carbs, not starting fluid. Secondly, have you checked spark and compression to start?? Both can be picked up cheaply at an auto parts store. And you didnt say what year it was?? How many cylinders??

GOover this as well

http://forums.iboats.com/showthread.php?t=158071

Re: mid 90's E 70 intermittent

Okay, first, plug the emergency lanyard in and start the engine. (little joke there)

You said "no fire" - I'm assuming (since you tried starter fluid) that you haven't actually checked for "fire." No fire, no start, no matter how much fuel. And heed hightrim's warning about starter fluid - if you wouldn't run the engine with no oil, then don't crank it with no oil.

Remove a spark plug, reattach it to the boot, hold it against the engine block and watch for spark while somebody turns the engine over. To avoid a good dose of electroshock therapy, use a plastic or insulated tool, or ask somebody you don't much like to help out.

If you don't see any "fire", then unplug the harness and jump the solenoid like tashasdad suggests above. To keep the engine from starting, unplug the other two spark plugs and connect 'em to the engine block with jumper wires, while looking for spark on #1. To jump the solenoid, touch one end of a wire to the solenoid large terminal leading from the battery, and the other end to the solenoid small terminal with yellow/red wire attached.

If you get spark like this, then you know it's a control problem.

Re: mid 90's E 70 intermittent

Talked to mech yesterday PM, said he was highly confident of the source of problem - said it seemed to be a "timing thing" under flywheel - I am assuming he is referring to crank position sensor. Said he got one reading as it sat, tapped it, got different reading and boat starts, tap again, different reading, boat no start. He said between the two readings one consistently correlated to boat starts, other reading no start. I only have limited experience with automotive, but it sounds like a bad position sensor to me (but what do I know) - plausible to you guys? TIA