dead cylinder

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: dead cylinder

What kind of motor? Typically a dead cylinder is caused from a blown head gasket, or a bad piston. Bad reeds can cause lower compression, but it wouldn't drop the compression entirely.
 

volangler

Recruit
Joined
Apr 17, 2011
Messages
3
Re: dead cylinder

71 evinrude 50hp. starts & runs, but smokes a bit & when i throttle up, it dies. checked the plugs & the lower one looks unused. runs fine in the driveway. even revs up. but on the water it won't throttle up.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: dead cylinder

A dead cylinder is one that makes no power when the engine is running or trying to start.

Loss of fuel, spark, compression, scavenging, timing and correct fuel/air mix all could make a dead cylinder.

Dead cylinders are the most common cause of an outboard pretending to run okay with no load but falling flat when asked to perform some work.

The quickest/simplest way to spot a dead cylinder is to disable the spark plug when running and getting no change in rpm.
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: dead cylinder

Yea, I didn't think about being dead, by means of spark. If it runs good in the driveway and ****ty in the water, then it sounds like you have something arcing out somewhere, like a coil or a spark plug lead. Out on the lake, the humidity level is so much higher, than it is in the driveway and electronic components that are somewhat problematic will act fine in the driveway, but give problems out on the lake. Check all your ignition components real good and make sure nothing is leaking.
 

volangler

Recruit
Joined
Apr 17, 2011
Messages
3
Re: dead cylinder

10-4. will do. i'll get back with you guys & let you know. thanks for your input.
 
Top