73 Evinrude Dead Cylinder

[ET]

I have a 1973 65hp evinrude triumph motor and cyl # 3 won't fire. I've changed the sparkplug, coil, powerpack, and stator. The cylinder has compression of a little over 100. Cyl #1 and 2 fire just fine. If I pull the #3 plug out while running there is no change, which isn't the case with the other two cylinders. I can't figure this out and I'm out of guesses of what it could be so i'm bringing my issue to the fine panel of experts. What could be wrong, and what should I test next? Also, could it be a something with the carb. Thanks for your help

ET

 

[The-Machinist]

Re: 73 Evinrude Dead Cylinder

What is the compression on the other cyls?

 

[ET]

Re: 73 Evinrude Dead Cylinder

They were all right at 100

 

[offshore100]

Re: 73 Evinrude Dead Cylinder

could it be a something with the carb. ET

Well, since it sounds like you've done all you could do re. spark, maybe carb#3 is the problem.
What does the plug look like? Wet or dry?

 

[BoatBuoy]

Re: 73 Evinrude Dead Cylinder

I have a 1973 65hp evinrude triumph motor and cyl # 3 won't fire.
ET

Do you mean that you can't get spark on cyl # 3, or that it's just not participating in the running?

 

[offshore100]

Re: 73 Evinrude Dead Cylinder

If I pull the #3 plug out while running there is no change, which isn't the case with the other two cylinders. ET

Certainly, check to make sure you have a spark in #3 plug. You don't have to be running to do that.

 

[jtexas]

Re: 73 Evinrude Dead Cylinder

The trick is to narrow the problem down *before* spending any money on parts.

remove #3 spark plug, reattach it to boot, hold it against the engine block while somebody cranks the engine. use an insulated tool to avoid electroshock therapy. if you see a sharp blue spark, then rebuild your carburetors.

 

[ET]

Re: 73 Evinrude Dead Cylinder

There is no spark on #3 and I'm pretty sure the plug is wet, I'll pull it out again today when I get home and post an update

 

[mikesea]

Re: 73 Evinrude Dead Cylinder

if you getting spark,fuel and compression,its possible your getting water into the cyl.via the exhust.the plates on the port side might be leaking water,when you remove the plug can you notice droplets of water,is the plug showing a rust color,.if you are getting spark,you can remove the carb cover,take some pre mixed fuel and spray it down the carb throat,if it fires ,you know you have a fuel prob,I would then suspect the carb,but,you could have a reed prob too,.check for spark first,if yes,try the throat trick,another thing you can do to check for water,carefully though,run the engine with the non firig plug out,put a piece of metal or glass close enough to the hole to see if water is appearing,but know that fuel may be present too,and has a good chance of firing if the dangling plug wire lites it off.just a couple old tricks,be careful

 

[ET]

Re: 73 Evinrude Dead Cylinder

I appreciate the help, i'll try all that out tomorrow