bad spark plug wire or bad carb?

[krampuppy]

I have a 25hp 1955 Evinrude that dogs out when you throttle up. Basically the motor gets louder but the speed is just a bit faster than idle. II initially thought it may be the carb... (and it still could be) but after changing the spark plugs and messing around with the spark plug wires I found that when I pull the top spark plug wire off the engine kills. I don't really know how to test the wires, but I know that the bottom wire gives some spark because it shocked me when I touched it. <br /><br />My problem is that I don't know how to make sure that the wire is giving off enough spark. If anybody knows... how difficult is it to find spark plug wires for this old boy? Also, is it very difficult to change the wires?<br /><br />Thanks to anyone who can help.

 

[BF]

Re: bad spark plug wire or bad carb?

if you take out bottom plug, put it back in the cap, and rest the electrode end of the plug to the block (edge of spark plug hole), you should get nice spark when you pull the rope. No spark tells you where to keep looking.<br /><br />But... my first gut feeling is that you want to test the compression on your bottom cylinder. It's only running on the top... maybe the bottom has no compression (rings/piston toast). If you don't have a tester, hold your finger over the plug hole, should have enough compression to push your finger off the hole when rope is pulled (not very scientific, but is quick way to tell if it has 0 compression). Of course a gauge is the right way to measure.

 

[krampuppy]

Re: bad spark plug wire or bad carb?

I have already tested compression and it seems to push enough air out when I pull the start rope. If anyone else has any advice please help. Also, how difficult is it to replace spark plug wires? Thanks

 

[krampuppy]

Re: bad spark plug wire or bad carb?

just putting this at the top of the board lookin for reply...<br /><br />Thanks

 

[DJ]

Re: bad spark plug wire or bad carb?

krampuppy,<br /><br />The engine is only running on one cylinder. I believe you've figured out which one-the top.<br /><br />Most likely, the coil that controls the bottom cylinder is bad.<br /><br />The coils are located under the flywheel along with the points and condenser. As long as you have the flywheel off, I would replace both coils, points, condensers.

 

[krampuppy]

Re: bad spark plug wire or bad carb?

Well it seems like I've got some work to do... I have heard everything from bad spark plug wire to possible bad coils and points. I have some mechanical ability, but I have never done anything like this before. If anyone else has any advice on how to change coils, points, and wires for this old motor please help.<br /><br />Thanks to all...

 

[krampuppy]

Re: bad spark plug wire or bad carb?

puttin back at the top looking for more input cuz tomorrow I am pulling this motor off my boat and am gonna try to fix if I can...

 

[pillatzki]

Re: bad spark plug wire or bad carb?

i had same problem, i found a crck in my under flywheel dist cap replaced that and got wires made at any evinrude dealeror johnson will run you about $30.00 for wires let me know if this helps