Re: Best year inline 6 90 hp to buy?
Any model built in the 80's will fit your requirements. A 115 will naturally use more fuel than a 90 hp. The difference in hp will be more noticable at higher speeds than lower.
About mid-80's Merc changed the power ratings from crankshaft to prop. So, the 140 became the new 115, the old 115 became the new 90. A mid-80's 90 hp will have the same power characteristics and fuel consumption as an older 115.
Around '78-'79 Merc built a 90HP Six that was crank-rated. This was a 115 with small ports & different tuning. Very torquey but not a revver. Probably the most economical of the later Merc I-6's. This would be a great motor on a lighter hull.
There's virtually no diff in reliability between the various HP models. Of course, a lower-hp motor will be less-stressed and may ultimately have a longer life.
Trouble spots for the later models revolve mostly around the electronics; stators and switchboxes were prone to failure. Any bad elex. parts are easily replaced and if you use CDI Marine aftermarket parts, virtually bulletproof.
It's also important to keep up on maintenance like impellers, fuel pump diaphragms & carb floats (ethanol fuels eat up the old stuff), and tuning/synchronization is crucial. All basic items for any motor, really.
But these are great-running motors with a unique look and sound that's mostly missing in newer motors.
Look for a clean motor that appears well-maintained. Get a compression check (or leakdown test, even better), and if you can, run it on a boat.
You'll know right away a good motor from a bad one. It should start right up, idle well in gear, accelerate smoothly, and not make any nasty sounds while underway.
Only the sweet music that a Tower of Power can make!
HTH & G'luck with the I-6 hunt...........ed
