Why does number 1 cylinder lose compression?

[surrender]

Been looking to repower the McKee and have been shopping used powerheads(or rebuilt) for a Cross Flow 90-115. Most I see for sale seem to have had the number one cylinder be the downfall of the motor. On the Cross Flow why is it that one is the one most often the bad one? One mechanic said it is because the fuel pump pulse is driven from that piston? He said a failing pump will cause that piston to run lean before the others. Hmm, any thoughts?

 

[emdsapmgr]

Re: Why does number 1 cylinder lose compression?

The crossflow fuel pump pulse line is ported on the #2, #4 side of the powerhead. Don't know what your mechanic is alluding to regarding #1. Many powerhead failures are related to fuel/lubricaton starvation-carb issues. Debris in the jets-that's a random situation.

 

[boobie]

Re: Why does number 1 cylinder lose compression?

On the cross flow mtrs it was usually the cyl's on the starboard side that would fail first due to carbon build up on the rings.