Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

[NoEcm]

http://forums.iboats.com/showthread.php?t=373564


For the last 22 years I've been running 100:1 oil mix in my 6hp trolling motor (per my original owners manual). Never get over 1/2 throttle and the plugs are caked with unburnt fuel/oil mix when I check and clean them once a year.

From what I understand, there has been a revison (along with a sticker) to increase the ratio to 50:1

I'm guessing that the motor has ~1200 - 1700 hours on it and is used strictly for trolling.

Should I switch the ratio to 50:1?................even after this period of time?

 

[1946Zephyr]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

Absolutely. If it hasn't seized up yet, then you're okay. Yes there was a revision from the 100:1 ratio. I too have a motor that was "designed to run on 100:1" The owner at the time had it all rebuilt, as a result of this recall.

 

[Vic.S]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

I would switch although just trolling has saved your engine from excessive wear but don't be heavy handed with the oil if that is all you do with it.

Also worth noting that the current recommended plug gaps are 0.030" maybe your manual says 0.040".

My 6hp is a 84 model, the year before they switched to 100:1.!

 

[tashasdaddy]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

trolling, go to 50:1, and keep the gap at .040. it is a trick used by trolling fisherman, to help keep the plugs from fouling. high speed gap at .030.

 

[kenmyfam]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

I'm with the "switch to 50 to 1 group as well.

 

[NoEcm]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

Done, 50:1 it is and thanks for the advice!!!

 

[Texasmark]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

Well, bein the redneck that I am, if you have been running 100 that long and your engine has survived, then why change. Only thing I would do is put some Sea Foam in the gas, like 4 oz per gallon for a couple of 6 gallon tanks, then on to the 1 oz per gallon recommended on the can and after the 4 oz treatment, change your plugs. Only other thing I would do is use synthetic TCW-3 oil. I know WW has it in Pennzoil brand.

I mean geez. If your engine hasn't seized in all those hours, why worry. Pfffffft the critics. If you don't like the carbon, I just told you what you could do with it.

Back in 1965 Scott Atwater's successor, McCullough came out with a little red 4 oz can of 100:1 oil for their engines. I happened to be a Scott owner at the time. They also had a yellow 50:1 oil that they marketed in an 8 oz can.

So, ask yourself, what was the difference? Obviously something beins this is OEM recommended oil and they had to back up their claims if run in new engines under mfgr. warranty and all, if customers had engine seizures or other damage as a result.

You don't suppose the 100 was synthetic do you.....naw, no way.....Yeah right.

My 2c.

Mark

 

[rodbolt]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

100 to 1 is sufficient lubrication for that motor while running.
the bulliten had nothing to do with running lubrication and everything to do with storage of the motor.
at 50 to 1 you have a margin of safty in case of a lean carb or an overheat and it can still protect the shiney parts while not used for a few weeks.

 

[JB]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

As rodbolt says, the switch away from 100:1 back to 50:1 had to do only with what sort of oil coating the innards had when placed in storage. Nothing to do with lubrication while running.

The stimulus for the change came from engines rusting the inner parts when stored.

OMC said go to 50:1, and that is what I recommend, too.

 

[JimS123]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

I have a 9.9 of the same vintage and used in the same way. Has about 1000 hours on it. Always used 50:1 and had fouling problems too. I tried the gap change and it was better but still not satisfactory in my eyes.

Then, I switched to Splitfire plugs, gapped per specs, and the fouling completely disappeared. They run clean, no smoke, no stumbling. The difference wasa amazing.

 

[F_R]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

Way back when OMC introduced their 50:1 oil, I was told by factory engineers that many of their motors would survive on 100:1 but they couldn't trust people to measure it accurately or control what kind of oil they used. So they held it to 50:1, even though Scott-Atwater was touting their 100:1. Meanwhile, Mercury was saying their motors were so finely crafted and precision built that they needed the best of lubrication.

And thus began the oil mix wars. Haven't ended yet.

Would I use 100:1?? Heck no. But it is obvious that it can be done.

 

[kenmyfam]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

Would I use 100:1?? Heck no. But it is obvious that it can be done.

And that about sums it up.

 

[R.Johnson]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

1200-1700 hrs. trolling time. Once at a factory service school we were told the average outboard will be used about 15 hrs. per year according to one of their studie's. Try the math on your figure's, then worry about possible damage.

 

[samo_ott]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

I'm in the switching to 50:1 group also but as mentioned, you sure have to look at the results so far... After 1500 hours or so if it's still kicking strong with good compression, then why fix it if it ain't broke... Or maybe go to 75:1 or so, no need to double the oil right off the bat...

 

[ezeke]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

What the service bulletin actually said was.....

 

[NoEcm]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

1200-1700 hrs. trolling time. Once at a factory service school we were told the average outboard will be used about 15 hrs. per year according to one of their studie's. Try the math on your figure's, then worry about possible damage.

Actually, the 70hp has 351 hours on it which averages just a little over 16 hours per year.

Once I hit the fishing spot(s), the 6hp takes over and thus the 1200 to 1700 hours of motor time.

hmmmm maybe I should try 75:1

 

[NoEcm]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

What the service bulletin actually said was.....

Thanks for the service bulletin. I'm leaning more towards 75:1 now.

 

[the machinist]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

I have been running 9.9s since 1978 on 50-1, but have found that in trolling the plugs fouled considerably. So used a 2nd tank mixed 100-1 just for trolling & over a 4 year period got over 50 hours with only one hickup that required reving the motor up to blow the snot out of the plugs.

I have done a lot of research & have finalized my mix to 75-1 of semi-sythetic & am VERY pleased with the outcome.

If I leave it for any period of time I run it in a tank on 50-1 for a while & then choke it to kill it, putting more lubricant inside for storage,

 

[NoEcm]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

I'm starting to look a little dumb now.

22 years ago I cut the mixture ratio label off a bottle of 2 cycle oil and pinned it above my workbench where I mix the oil/gas. The chart on the label had the following:

At 100:1
Add 2oz of oil for 1 gallon of gas
Add 3oz of oil for 2 gallons of gas

Using an online Gas Oil Mixture Ratio Calculator I figured out that:

Add 2oz of oil for 1 gallon of gas = 64:1
Add 3oz of oil for 2 gallons of gas = 85:1

So, for the last 22 years I've been running probably close to 75:1 as near as I can tell.

Calculator: http://www.csgnetwork.com/marineoilfuelcalc.html

 

[1946Zephyr]

Re: Oh-Oh........I've been running 100:1 oil mix in my 1988 6hp since it was new

That's a pretty cool site. It turns out that a lot of old motors I've actually been running 16:1 I thought that 8oz per galon was 24:1 but 24:1 is just under 6oz per gallon