Evinrude 135 HP v4 intermittent spark on one cylinder.

[kevin88]

I have an Evinrude 135 HP v4 (135489-b) and I have recenly replaced (in this order) : the rectifier, stator, and power pack. <br />The rectifier shorted and blew the power pack.. So I replaced them and now I have an intermittent spark problem on #1 cylinder and only on the #1 cylinder. <br />When the engine runs at low RPM's (below 3,000) I get no spark at all using a timing light or I may get an extremely weak spark that is 180 degrees out.. <br />A week ago it ran fine and had good enough spark to set the top end timing with.<br /><br />Could this be a new power pack gone bad? And if so what could have caused the power pack to go besides a bad rectifier which obviously wasn't the case...<br /><br />Thanks for your help.

 

[DJ]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

kevin,<br /><br />Look at and clean every ground wire, on the engine, you can find. That includes the negative battery connection to the engine block.

 

[ddbyrd3]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

Kevin, I had kinda that same problem when I replaced my power packs. Check the 2 pin plug connector, I had bent a pin and it was outside the insulation causing an intermitant spark..

 

[McGR]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

You may want to swap the coil on the intermittant cylinder with a coil from a good cylinder. This should determine if you possibly have a bad coil on #1. If after swapping you are still intermittant on #1 then the coil checks OK. If the intermittancy follows the #1 coil that coil is suspect.

 

[kevin88]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

Which 2 pin connector? There is only one 2 pin connector on my entire motor going from memory... Goes to something, and I don't even know what it is... Not the rectifier, stator, or power pack but it is fused... Any ideas?<br /><br />I have successfully done the DVA checks before for the trigger outputs on the bad power pack and got 100-110 VAC but now the voltage jumps so badly I can't get a reading at all.

 

[kevin88]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

I have also swapped the #1 and #3 coils at both ends and got good spark out of the #1 coil when connected as #3<br /><br />Also: trigger 1/3 resistance is: 8.1 Ohms<br /> trigger 2/4 resistance is: 8.4 Ohms<br /><br />With the old power pack installed all the voltages were correct but it didn't fire at all. With the new power pack the voltages are everywhere and I get no fire on #1.

 

[McGR]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

K88 - I think ddb3 was assuming you had a somewhat newer crossflow V4 (1978+). These motors have two powerpacks (one per 2 cyl.) and have small two conductor pin connectors. I assume you have a mid 70's motor that uses a single powerpack with ring terminals. <br /><br />Another thing you may want to try is swapping the sensor inputs to the power pack and see if it has any effect on the spark. Obviously, the motor won't run like this, as the timing will be completely out of whack - but it does allow you to substitute one sensor with the other for test purposes.

 

[kevin88]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

Do you mean to swap sensor wire #1 with #3 or to swap the two sets (1/3 and 2/4) respectively?<br />This part of the ignition system has me baffled. If there are only 2 trigger coils and #1 and #3 are sharing one how could only #1 be affected by a bad trigger?

 

[ddbyrd3]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

Sorry K88, as McGR says, I assumed you had a newer crossflow...

 

[kevin88]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

No problem ddbyrd3. I just realized yesterday that the motor has no spark at all on #1. I was checking for spark with a timing light with the motor running and the light was picking up spark from other wires.<br />Also noticed that the spark plug covers on #1 and #2 cylinders had considerable rust on the connection. Could this rust have caused the new power pack to go bad?

 

[kevin88]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

Hopefully this is my final update on this. I learned that the #1 output on my new power pack has died and the pack is burnt. When I asked a reliable marine mechanic he recommended testing the ignition coils for resistance. I tested all 4 coils by connecting one end of my multimeter to the #1 coil output on the power pack and the other lead to each of the spark plug connectors. #1 measured 200K Ohms and the rest #2-4 measured just 2k Ohms. I was told a high resistance reading on the coil would be enough to burn up a power pack. So I'm off to buy a new coil and another new power pack. Wish me luck.

 

[fseventy]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

so..... whats the verdict?

 

[kevin88]

Re: Evinrude 135 HP v4 intermittent spark on one cylinder.

The verdict is the spark plug boot on the #1 cylinder had excessive rust on it which caused high resistance for the coil. This was causing the intermittent spark and also caused the coil to feed back into the power pack. I replaced all the spark plug boots, the #1 coil, and the power pack and now I'm good to go...