Still wondering is 1:50 the best.....

[Emerald Fox]

Yes, Iowa, a good idea! You know Bill Bryson is from Des Moines, I've just been re-reading his book 'The Lost Continent', very funny - and positive comments about Iowa <br /><br /> Now, I don't mean to keep on the subject, but I just took out the 2 new spark plugs I put in to this second-hand engine, of which I know not much (previous owner old guy who had engine serviced regularly I hear, not driven much, and looks quite clean and tidy). I put the plugs in last Saturday and they have run for about 7 hours. I took them out just now just to see what they look like, and they're already a bit oil-burnt-on-looking.<br /> Would it be complete madness to change the 2-stroke oil from 1:50 to, say, 1:60 so that the plugs stay cleaner? Or will I just hear a big BANG!??! Has anyone else done this? Would it do harm if I tried for the next run of a couple of hours (and then I'd look at the plugs again to see if they are cleaner)?<br /> It's not in the interest of saving oil/money, just trying to give the engine the best all-round consideration.<br /><br /> Thanks again!<br /> Ross Turner

 

[jim dozier]

Re: Still wondering is 1:50 the best.....

I don't know the answer to this question. Although alot of people have opinions on it they probabyly don't KNOW either, including the manufacturers. The problem for the manufacturers of any product is that you have to make some assumptions about end use for millions (or at least a large number) of people that may use the product. I used to work for a pharmaceutical company and the way they come up with a dosage for a medicine involves a lot of basic science, animal research, reasonable guesses, field trials and ultimately a recommended dosage. Then it hits the market. And I will tell you, that despite the best science, and the best of intentions, when a couple of hundred million people use it you will find in some products (not all) and I have personal experience with this, that they got the dosage wrong for some of the people. They will have to change the recommended dosage for all or at least some of the intended uses.<br /><br />What, you might say, does this have to do with premix in an outboard? The lubrication mixture is a guess based on basic science, bench testing, reasonable guesses, field trials and ultimately a recommended mixture. Then it hits the market. And I will tell you, that despite the best science, and the best of intentions, when a couple of hundred million people use it you will find in some instances (not all), that they got the mixture wrong for some of the people. They will have to change the recommended mixture for all or at least some of the intended uses.<br /><br />Older engines with less exotic metallurgy and sleeve bearings used to get 20:1 or something similar. Improvements in engine design (roller and needle bearings) and oils allowed a change to 50:1. Some manufacturers ultimately went to 100:1. Oil injection systems (which varies the mixture from something like 100:1 at idle to 50:1 at WOT) were developed. I have read (but have no personal experience) that OMC backed off of the 100:1 because the oil film on unused engines was insufficient to protect from static rusting.<br /><br />If you took a million boaters with the same engine and told them all to use 150:1 some would never have a problem and think its the best thing since sliced bread. Some would have engines that rusted in the driveway shortening their engine life. Some would seize pistons (like that never happens at 50:1) and be unhappy. Some would blow up and kill somebody and they would sue and possibly win . If you are a manufacturer what mixture would you recommend? How are you going to know who will get by and who won't? The answer is you hedge your bets and pick a number that is a compromise between safety and performance that will, you hope, give the most amount of customers a happy experience with the product while reducing the liablility for your company. <br /><br />Use whatever mixture you want, just don't complain to the manufacturer if you have a problem.

 

[G DANE]

Re: Still wondering is 1:50 the best.....

OMC in fact did recommend the 1:100 mixture for some years. But as they changed it back tells me that 1:100 is mixing oil too low. With the CDI ignition you can run sparkplugs till they are worn up before they fowl, at 1:50. I'd stick with that.

 

[cobra 3.0]

Re: Still wondering is 1:50 the best.....

I believe looking at some of the previous topics on oil, that amsoil synthetic could run at 80 to 1 and even 100 to 1. Users claim less smoke and little and very clean operation.

 

[LubeDude]

Re: Still wondering is 1:50 the best.....

The way I see it, With regular TC-W3 oil, I wouldnt change the ratio, at least not leaner. When I recommend changing ratios I always say to go on the richer side and you do not want to do this in your case. So, you can either go with a little hotter plug to help burn off the carbon, (not always a good choice) especially if you run WOT a lot. Or go to a full synthetic such as Amsoil or Pennzoil.

 

[bubbakat]

Re: Still wondering is 1:50 the best.....

Try gaping them a little wider and see if that helps.<br />I gap mine at 40 though book says 30 and it gives me a cleaner plug and better idle.<br />85/hp evenrude

 

[DJ]

Re: Still wondering is 1:50 the best.....

Make sure you are using the CORRECT Champion plugs and keep it at 50:1.

 

[DHPMARINE]

Re: Still wondering is 1:50 the best.....

Ross are you changing fuel ratio and maybe plug heat range because of operating problems,or because of the way the plugs look?Generally speaking,if you run 50:1 and the called for plugs,and it doesn't run right you have a problem elsewhere.I would not experiment because of how plugs look,but rather for how it ran.<br />DHP

 

[Jack Shellac]

Re: Still wondering is 1:50 the best.....

You could probably safely operate at a leaner mixture if you never ran the engine at high speeds. Since this is unlikely, I think I'd stay at 50:1. The nuisance of cleaning/changing plugs is nowhere near as bad as a blown powerhead.