Low compression top port cylinder '86 Erude 90 crossflow

[V153]

125psi in other cylinders, 105 in this one. Plug looks milky. Water intrusion from bad head gasket? Something else?

Any help would be greatly appreciated. Thanks!

 

[SparkieBoat]

Re: Low compression top port cylinder '86 Erude 90 crossflow

pop your head cover off and see...I would do a decarb also. watch them bolts, they like to snap.

 

[emdsapmgr]

Re: Low compression top port cylinder '86 Erude 90 crossflow

Possible that the seal ring on the head gasket is damaged on that cylinder. That will decrease compression and may let water into that cylinder. Pull that head off to check it. You'll need to replace that head gasket when you reinstall it. If you are still getting water into that cylinder, it could also be a leaky exhaust cover gasket. When these leak, water ingress typically affect the lower cylinders. Neither of these jobs is considered very technical and you have good access to both components.

 

[daselbee]

Re: Low compression top port cylinder '86 Erude 90 crossflow

Very common in those engines is overheating over time as the water deflectors slowly swell, shift, collect scale.....
The upper cyls overheat, rings break, cyls score....etc.

You have to pull the head.