650 Mercury Thunderbolt

[oresaway]

I am not firing on the 4th cylinder. I am also getting moisture at the plug. The motor starts up great and has never died out on me. I am just not getting the power I should. I have pulled plugs and test out fine as far as the spark. Any Ideas?

 

[The Marine Doctor]

Re: 650 Mercury Thunderbolt

If you are getting water on the plug it may be because there is no Ign there...Spent exhaust escaping from the cyl keeps the water out.<br /><br />Next...you may have a blown base gasket...not the one directly under the block but the second one. Below the adapter plate.<br /><br />OR...a blown exhaust gasket.<br /><br />TMD

 

[greasemonkeyozi]

Re: 650 Mercury Thunderbolt

It "could" be one of two things wht your not firing on your forth cylinder. Your switch box, or your coil pack. <br /> Before I go any further in giving any advice on troubleshooting, give us as much detail about your motor. So far we know its a 4 cylinder...