oil ratio debate 1949 keikhaefer

[alittledinghy]

my project is a 7.5 hp motor that hasn't been run in a really long time.I've already done the water pump and rebuilt the carb,changed the lube and greased whatever needed greasing I stopped at a "Merc" dealer to pick up some two cycle oil and asked the service guy what ratio fuel oil mix i should use. He told me to run this 1949 motor at 50:1. Doesn't sound right to me, even given the advances in oils. Anybody have an opinion ?

 

[Chinewalker]

Re: oil ratio debate 1949 keikhaefer

Hi Dinghy,<br /> DO NOT run that motor at 50:1. Although it has roller and ball bearings through most of the powerhead, it doesn't have them on the center main, nor does it have the scavenging capabilities of the later motors. As such, it'll need about a 24:1 ratio, which is what I have run in my vintage Mercs for years. I run 16:1 in my racing motors. Also, consider that the seals, etc. are over 50 years old, and the extra oil will make them work a little better.<br /> Do consider doing a decarbon job to your motor, as it has not had the benefit of running the modern, cleaner burning oils, and likely has a fair amount of carbon built up in the ring grooves, exhaust passages, piston crowns, etc. The old KE4s are solid little motors and should give you good service when set-up right and taken care of.<br /> Have fun with it!<br />- Scott

 

[Prospector]

Re: oil ratio debate 1949 keikhaefer

What ratio mix do I use for a 1965 Merc 6HP?

 

[JB]

Re: oil ratio debate 1949 keikhaefer

Prospector.<br /><br />Please do not hijack another thread with a new question.<br /><br />Please post your question in it's own thread.<br /><br />Thanks

 

[alittledinghy]

Re: oil ratio debate 1949 keikhaefer

Hi Scott,<br />That's pretty much what i was thinking. Maybe 16:1 for the first tank. I have a can of Seafoam next to the motor, just waiting to be used. Now i need to scrounge up an old drum so i can start it ! those things are getting tough to find around here. Thanks. Jerome

 

[dajohnson53]

Re: oil ratio debate 1949 keikhaefer

I think you'll find a conventional trash can will work fine for a small motor. Sounds like a fun project.