no compression 1 cyl 140hp 1986 rude

[dcolpitts]

I going to start a new tread, can't find the original. pulled heads today and confirmed no compression problem. lower starboard side had a broken pistion on the edge of the piston. all pistons are loose but not much scoring. I would like to confirm the bore of the pistons. on the port side the # is 393556, starboard side is 391481. are these #'s oem and are they std bore or other. thanks in advanced for any info anyone can supply.

 

[OBJ]

Re: no compression 1 cyl 140hp 1986 rude

Those are standard bore pistons okam.

 

[Solittle]

Re: no compression 1 cyl 140hp 1986 rude

If a cylinder has been bored the overbore will be stamped on the top of the piston.

 

[jy118lfd]

Re: no compression 1 cyl 140hp 1986 rude

Sounds like you tripped a ring on a port due to carbon and cylinder overheating (lugging).If you are going to rebuild check the bores as the words of Dhadley most of the bores will be out of round due to the heat buildup and need to be bored. But if they are in spec you can hone and rering. For some reason all crossflows do this, if they are lugged, and it always seems to be starboard bottem v6 or v4. All of the crossflows on e-bay for sale always say low compression in one hole and it is number 6 or 4

 

[dcolpitts]

Re: no compression 1 cyl 140hp 1986 rude

thanks for the replies, it did catch a ring but not surpising the motor is 18 yrs old. this motor runs 10-20 hrs 40 weeks a year. time for a rebuild, this is a great motor and anf can look foward to another 18 yrs. thanks again.