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View Full Version : Getting something off my chest



194265
08-13-2010, 04:27 PM
Somethings that have been bugging me lately. When ever we talk about "Mercury Outboards" the subject always gets around to the six cylinders, whether inlines or V's. Now don't get me wrong, they are Great engines and perfect exsamples of state of the art engineering. But now some questions, inlines, "allways prop them for 6000 RPM or higher or they will melt down'. What about the famly man wants to cruise around all day at 3500 to 4000 RPM, is he going to have melt down problems. You and I know the answer, but alot of people reading this don't. So lets tell them, and how about some of the other Merc models. You know like the 65 hp three cylinders, 650 four , 850 four, 70-90 HP three cylinder and the big fours. We all say their poochs, can't get out of their own way, but yet they sold alot of these engines and people had fun with them. My first boat was a 1967 Glastron 143v with a Merc 650 it would run all day 5700 and 37 mph. and never had a single problem with it. Sure some of them had some problems and wouldn't go 80 mph, but I liked them all and still have alot of fun with them. Sooooooo lets give them respect they deserve :D:D:D:D I feel better now:rolleyes:

Mark75H
08-13-2010, 05:19 PM
prop them for 6000 RPM

Not run the Direct Charge inlines 6,000 ... prop them for 6,000. This means the motor must be able to spin up, not you must spin it up.

My uncle had a 15 ft Whrilwind with a 65 Merc ... it pulled skiers day in and day out with a 3 blade and spun up a 2 blade Michigan to 42 mph with 4 people in the boat. There would not have been much of a chance of doing the same thing with a motor rated for less power. It was a good workhorse.

Tim Kurcz
08-17-2010, 09:41 AM
As a laker kid, I learned to ski behind a MK58A on a 14' Speed Queen, and ran the stink out of a neighbors Merc 350 in a 14' MFG. The baddest boat on the lake was a 17' Thompson with a Merc 1000 (year was 1968). We couldn't hurt any of them despite hours of skiing and full throttle chasing. The only Merc I remember having problems was a new 402. It suffered ignition problems for years. Unfortunately, it belonged to a converted Evinrude guy who later swore off Mercs as a result.

As a young Mercury Mechanic (1972-1976) I worked on all of them - basically built to aviation standards. So far as operation, it was better to let them rev than lug. For Sam and others: The only sixes that had problems were the first 1500's (in-line). All were owners fault because 16' Baja's and Checkmates were all the sudden powerful enough to jump. Most came in with rose petals missing from the resulting over-rev.

Fairlane Boats and Motors in Detroit - the only Merc dealer in the state that stocked all racing parts. Known as the "Home of the clamp on kids", just about every Stock Outboard and Mod racer purchased their parts there. It was normal business to overhaul/tune up/tank test the Mark series race engines there. If we only knew!

Mark75H
08-17-2010, 04:09 PM
For Sam and others: The only sixes that had problems were the first 1500's (in-line). All were owners fault because 16' Baja's and Checkmates were all the sudden powerful enough to jump. Most came in with rose petals missing from the resulting over-rev.

We aren't talking about problems when new, we are talking 30 and 40 years down the line with today's junk gas. Lug these tuned exhaust motors and you will pay in melted pistons. Let them rev up easily and get over plane quickly and they will serve you well. (Of course, putting one on a 400 pound boat helps, too:p )