Oiled gas question.

[awthacker]

My boat not having an oil reservoir, when I installed my 94 Evinrude two-stroke I removed the fuel/oil VRO pump and replaced it with a fuel only pump, capping off the oil inlet to the engine but leaving all of those hoses in place. I premix 50:1. It smokes a lot and I hear the phrase Better Smoke than Broke a lot.

I wonder, since I very rarely run wide open... do I really need 50:1? Isn't that pretty much WOT ratio? Shouldn't I be able to mix 40:1 and be fine and result in less carbon build-up? Doesn't the VRO pump somewhere around 150:1 at idle and 50:1 wide open? What would be the worst case scenario if you were mixed at 40:1 and ran WOT for, say, 5 minutes?

[THEFERMANATOR]

Originally Posted by awthacker

My boat not having an oil reservoir, when I installed my 94 Evinrude two-stroke I removed the fuel/oil VRO pump and replaced it with a fuel only pump, capping off the oil inlet to the engine but leaving all of those hoses in place. I premix 50:1. It smokes a lot and I hear the phrase Better Smoke than Broke a lot.

I wonder, since I very rarely run wide open... do I really need 50:1? Isn't that pretty much WOT ratio? Shouldn't I be able to mix 40:1 and be fine and result in less carbon build-up? Doesn't the VRO pump somewhere around 150:1 at idle and 50:1 wide open? What would be the worst case scenario if you were mixed at 40:1 and ran WOT for, say, 5 minutes?

40:1 is richer on oil than 50:1. The VRO is designed to oil around 40-50:1 at WOT(depending on the size of the engine, larger engines pull more fuel and thus the pump richens up the oiling more), and drops down to about 75-100:1 at idle. I've rejetted several engines now to run on pre-mix, and if you run GOOD quality oil they don't smoke bad at all running 50:1 premix. MERCURY QUIKSILVER oil has been the WORST oil I have used as far as smoke goes, and PENNSOIL blend has been the best to keep the smoke down. i'm not a PENNSOIL fan myself, except for 2 stroke oil. In which case I use it in EVERYTHING. Every boat I work on, have owned, and any 2 stroke engine I have or worked on right down to lawn equipment gets it.

[awthacker]

Yeah I guess I meant 60:1, lol. Sounds like the recc is to use the pen soil and stick with 50:1, though. Thanks

[garbubba]

I expect that pump will last a while, but my neutered engine will NEVER have a low oil issue. Mixing 50 to 1 is as easy as it gets. just as easy as filling 2 tanks. Only trouble I have is pulling a shrimp trawl, after a couple hours it will carbon up, just a short run clears things up though.

Never heard that about quicksilver oil, I use it or Castrol, any opinions on Castrol 2 stroke oil?

[Destroyer]

Originally Posted by garbubba

I expect that pump will last a while, but my neutered engine will NEVER have a low oil issue. Mixing 50 to 1 is as easy as it gets. just as easy as filling 2 tanks. Only trouble I have is pulling a shrimp trawl, after a couple hours it will carbon up, just a short run clears things up though.

Never heard that about quicksilver oil, I use it or Castrol, any opinions on Castrol 2 stroke oil?

In my more than 40+ years of boating I've mixed thousands of gallons of premix, everything from 20 - 1 for my British Seagulls to 50 - 1 for my neutered 225 Johnson, and I'm not even going to count the endless chainsaws, snow blowers, string trimmers, etc., etc. One of the BEST gadgets I ever bought was a premix plastic bottle from Walmart (http://www.walmart.com/ip/Shoreline-...ottle/17128586) that shows you how much oil to mix for whatever amount of gas you want to use. Less than $5 and I never make a mistake on the proper ratio. I know that premixed gas will never give me a low oil issue.
BUT
There's a reason that manufacturers put VRO pumps on outboards. They cost money to make and install, and for whatever the reason, they are there for a reason. That being said, I have my own reasons for desiring to not premix if possible and if it's safe for my engine(s). My main engine is a 2 stroke, but my kicker is a 4 stroke. I'd like to run them both from the same tank so I don't have to carry extra gas cans. What's good for me might not be good for others.

[THEFERMANATOR]

Originally Posted by Destroyer

There's a reason that manufacturers put VRO pumps on outboards. They cost money to make and install, and for whatever the reason, they are there for a reason. That being said, I have my own reasons for desiring to not premix if possible and if it's safe for my engine(s). My main engine is a 2 stroke, but my kicker is a 4 stroke. I'd like to run them both from the same tank so I don't have to carry extra gas cans. What's good for me might not be good for others.

Yep, the average boater doesn't want to premix there oil or can't premix it properly. AH, what the heck. 100:1 is close enough, right? Or who cares if it smokes, I'm going 25:1. And the next thing you know it is carboned up and stuck a ring. I know YAMAHA continued to offer many 2 strokes as premix or oil injected models well into the 2000's, and had little to no trouble out of them. Basically oil injection took the user out of the equation in many aspects as a source of trouble by putting in a system to do the work for them, and warning horns to tell them when they made a mistake.

[Destroyer]

Originally Posted by THEFERMANATOR

Yep, the average boater doesn't want to premix there oil or can't premix it properly. AH, what the heck. 100:1 is close enough, right? Or who cares if it smokes, I'm going 25:1. And the next thing you know it is carboned up and stuck a ring. I know YAMAHA continued to offer many 2 strokes as premix or oil injected models well into the 2000's, and had little to no trouble out of them. Basically oil injection took the user out of the equation in many aspects as a source of trouble by putting in a system to do the work for them, and warning horns to tell them when they made a mistake.

Exactly correct....and I suspect that the EPA and their overzealous a$$holes might have had something to do with it also. Just like the mandate for 4 strokes.