90 crossflow, 15 good years..and then.

[ondarvr]

Had an odd lean sneeze at idle one day, figured something was plugging a low speed jet so cleaned the carb, it was spotless inside but I figured maybe I just didn't see the gunk. Took it back out and it ran exactly the same, still had the lean sneeze at idle when cold, once warm it would go away. I must have had the carb apart a dozen times thinking I missed something, I had even identified the cylinder with the issue. Ran it today and had the same problem, pulled the plug wire off and it idled perfect, put it back on and had the lean sneeze. Did a compression check, 120-120-120-40, pulled the head and found the piston ring locating pin had backed out, a nice groove from the pin, broken ring and piston, plus the beat up head.

Now the decision, do I rebuild it as a 90, or do I buy a rebuilt 115 power head for around 2,500

The other option is just get a different used motor and bolt it on, which will cost more than a new power head.

 

[Bosunsmate]

Re: 90 crossflow, 15 good years..and then.

Rebuild, its already apart.... and take the boat on holiday with the change

 

[emdsapmgr]

Re: 90 crossflow, 15 good years..and then.

An unfortunate turn of events. Even if you bore the bad cyl, and put in a new piston, 4 new ringsets, hone the other 3 cyls, a used head- you'll be into it for a lot less than $ 2500. At that point, you have an engine that is a known entity to you-ready for another 15 years. Maybe you'd want to upgrade to a set of 115 carbs, intake filler blocks and some composite reeds during overhaul.

 

[ondarvr]

Re: 90 crossflow, 15 good years..and then.

I won't put it back together without a complete rebuild with all new pistons, boring, bearings, etc, so the cost won't be much less than a rebuilt power head. I don't trust the other three pistons now, I don't really trust a remanufactured power head either, nor do I trust used motors.

 

[boobie]

Re: 90 crossflow, 15 good years..and then.

Rebuild it yourself and then you will know exactly what you have. JMHO