No spark with plugs in. 99- 70hp johnson

[rkmnoles]

I have never run across this before but, this engine has spark with plugs out and no spark with plugs in. 230 volts at stator. Only getting 30 volts between coil and power pack. The spark seems to be a little weak but will still jump a 7/16 gap. Any Ideas as to power pack or stator issue. Timing is good. Thanks in advance. Kevin

 

[boobie]

Re: No spark with plugs in. 99- 70hp johnson

How fast is the mtr spinning over with the plugs in. Should spin over a min of 250 rpm. You may have a bad battery or corroeded bat/cable connections or a weak starter mtr.

 

[rkmnoles]

Re: No spark with plugs in. 99- 70hp johnson

Turning over good,battery good, starter good, cables are fine. It is an ignition issue I think so I am trying to isolate. Also timing is good.

 

[boobie]

Re: No spark with plugs in. 99- 70hp johnson

What kind of voltmeter are you using to check the voltage outputs ? Does the mtr run ??

 

[rkmnoles]

Re: No spark with plugs in. 99- 70hp johnson

Well seeing how it has no spark with the plugs in it doesn't run. Ran fine 1 week ago.

 

[andrewddrennon]

Re: No spark with plugs in. 99- 70hp johnson

Not sure how you checked the timing if you have no spark?!? If you have a nice blue spark on each cylinder that will jump a 7/16 gap then thats probably not your problem. Will the motor just not start? If so try spraying some fogging oil or mercury power tune in each cylinder and see what happens.

 

[boobie]

Re: No spark with plugs in. 99- 70hp johnson

IMHO I don't think the mtr is turning over fast enough, but I'm not there. Been through it before.

 

[bob johnson]

Re: No spark with plugs in. 99- 70hp johnson

I agree with boobie... I had and have the same issue..when it was cold the motor cranked over fine...or so it sounded like....but it just wasnt fast enough to make spark.

there needs to be a minimum of rpm to EVEN MAKE spark....spark isnt a guarenteed automatic thing!!! it has to be produced...and it is when the flywheel rotates OVER a certain rpm..

I cleane d everything and charged my batteries and I got spark....a little weak in the cold weather...just wouldnt turn over enough....even though it sounded fine..

in the summer never had that issue....

it also maybe the starter...if the batteries are charged good... and the terminals all clean...a weak turning starter could cause the same thing..

I run my boat all winter up in the northeast in temps down to zero....I have an oboard charger...i plug that thing in every time i come home now.

the reason you have spark when the plugs are out is because there is no back pressure from compression slowing the starter down

try this to prove it...take a spare spark plug and put it in one of the plug wires. take all the other plugs ( with no plug wire attached)and put them in their spots in the head and tighten up...see if your plug in the plug wire has spark now!

bob

 

[boobie]

Re: No spark with plugs in. 99- 70hp johnson

Well said Bob. Good idea !

 

[bob johnson]

Re: No spark with plugs in. 99- 70hp johnson

another great reason to have a simple spark tester....leave the plugs in and put the tester in between the plug and the wire


bob

 

[boobie]

Re: No spark with plugs in. 99- 70hp johnson

I have some of those in line spark testers and don't like them. I still use the adjustable open air gap ones between the plug wire and ground.