no compression on middle cylinder

[WINDJAMMER]

my 91 force 70 hp has no compression in the middle cylinder. the foam on the inside of the cowl has been dry-rotting and falling off motor was missing the carb. cover when i bought it so it probably has been sucking up pieces of foam.. i was running the boat and it made a noise and stopped. started right back up and got me home, had rough idle. just did compression check, motor was stone cold #1 =120 #2 = 0 #3 125. # 2 piston is moving up and down in the cylinder and can't see any damage from the sparkplug hole. looking for direction on what to do first-pull and check reeds or pull head and look at cylinders

 

[The Marine Doctor]

Re: no compression on middle cylinder

I would remove the head as it is less work. If there is 0 compression it is most likely you will have to remove it anyway.<br /><br />TMD

 

[ppresley]

Re: no compression on middle cylinder

I had to make a post after reading your discoveries. I am in the middle of rebuilding a 85hp US Marine Force motor that a neighbor bought, thought it ran ok but needed a tune up. Had me check it and found 0 compression on number 2. Simular results to your readings. Pulled the head and found burned up top of piston. Figured it was lean #2 carb for too long and burned up the piston. Upon cleaning engine, found the fuel drain reed valve for that cyclinder was clogged with excess gasket sealent material. <br />So, having to replace one piston and all the rings, with new gaskets and seals through out the entire motor. Will be nice when it's finished.