Buying a used Yamaha

Fish Head

Cadet
Joined
Feb 6, 2002
Messages
22
Does anyone know how well a 1991 90hp Yamaha holds up. I am interested in a used Proline 17'C.C. boat with one.<br />What compression p.s.i range should I expect and how much cylinder pressure variance is acceptable. A mechanic told me Yamaha has weak lower units but I never heard that before. Any tips?
 

Fouled Plug

Ensign
Joined
Jun 29, 2001
Messages
935
Re: Buying a used Yamaha

Depends on the care the previous owner gave it. Compression should be over 100psi with 15% or less variation. Check the lower unit lube as well for water, shavings, etc. Never heard of that lower being "weak". Post again when you get the numbers from the test.
 
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