Injection or Pre mix?

Knot Working

Seaman
Joined
Apr 1, 2003
Messages
50
Hi, I am installing a 5 year old Yamaha 250Hp on a brand new hull. I had the motor set up for pre mix on my other boat as I once blew a motor because the oil sensor failed. I would like to have the new boat set up for pre mix as well. Am I being too paranoid? Just wondering if anyone else preffered a pre mix set up? Thanks
 

Knot Working

Seaman
Joined
Apr 1, 2003
Messages
50
Re: Injection or Pre mix?

Thanks Rick, That definately makes me feel a little better.<br /><br />M-
 

ob

Admiral
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Aug 16, 2002
Messages
6,992
Re: Injection or Pre mix?

Ditto on premix.Others may differ.
 

boatingfool

Chief Petty Officer
Joined
Nov 30, 2002
Messages
610
Re: Injection or Pre mix?

From what I understand most engines with auto injection do not have a kill switch if the oil stops.<br /><br />Sounds like premix is piece of mind !!<br /><br />Why dont they have a kill switch????
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Injection or Pre mix?

Liability issues I would imagine,in the event it tripped the engine at WOT and the operator was ejected from the boat might be one scenario.
 

boatingfool

Chief Petty Officer
Joined
Nov 30, 2002
Messages
610
Re: Injection or Pre mix?

Alright maybe not a kill switch but what about a warning light??<br /><br />That way you can control tthe decceleration.
 

Knot Working

Seaman
Joined
Apr 1, 2003
Messages
50
Re: Injection or Pre mix?

Does 50:1 or 1 pint per 6 gallons sound right for this engine? Thanks,<br /><br />M-
 

ob

Admiral
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Aug 16, 2002
Messages
6,992
Re: Injection or Pre mix?

Many outboards have warning lights and or audible alarms when no oil sensor detects condition.Problem is at 6000 RPM the pistons have slapped several thousand back and forth trips bafore the operator can react.Mine had the audible no oil and low oil alarms that are now reduced to disconnected play toys and the oil reservoir serves as a handy two cycle oil dispenser complete with pumping bulb and conveniently located spigot.
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Injection or Pre mix?

Knot<br /><br />Yes, 50:1 is right for your engine.
 

ob

Admiral
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Aug 16, 2002
Messages
6,992
Re: Injection or Pre mix?

Knot Working,To be exact 50:1 is 1 pint per 6.25 gal. of gas.I like to mix mine at that to minimize oil richness and reduce coking ,particularly if engine is run at slower speeds frequently.
 

plugger

Petty Officer 3rd Class
Joined
May 28, 2002
Messages
75
Re: Injection or Pre mix?

oh, your making me nuts.....<br />is the vro type verified as unrelible<br />and if so why are all newer boats set<br />up this way<br /><br />whats the point of having a low oil alarm if its too late<br />does relibility differ with boat <br />manufacture
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Injection or Pre mix?

whats the point of having a low oil alarm if its too late
That's true there is a "Low Oil Alarm", and it will only tell you when the level in the tank is low, not when it fails to make it to the pump. Most failures are due to improper Maintenence or broken oil lines due to wear. If the system is properly Maintained and inspected every year, the odds are that you won't have a catastrophic failure. Most times it's not the pump that gets you. It's what happens from the oil tank to the pump that can hurt you and I'm just not willing to take that chance..
 

bret walters

Seaman
Joined
Mar 2, 2003
Messages
73
Re: Injection or Pre mix?

go with the injection system, yamaha's is reliable and proven, the sensor that fails most on all manufactures oil injection is the sensor holding on to the steering wheel!!!! :) :)
 

Knot Working

Seaman
Joined
Apr 1, 2003
Messages
50
Re: Injection or Pre mix?

That is exactly what happened on my last motor (also Yamaha) the pump failed and no alarm. Resevoir still had a full tank. I had a certified Yamaha mechanic tune my motor at the begining of the season as I am still pretty new to boating. Guess I will pre mix- that way I will spend more time enjoying and less time worrying.<br /><br />M-
 

Firestomper

Seaman Apprentice
Joined
Mar 25, 2003
Messages
34
Re: Injection or Pre mix?

I have a 1986 johnson 40 hp VRO proped up against my building thanks to the VRO no oil destroys an engine in short order..in my case anyway
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Injection or Pre mix?

plugger , while I'm somewhat educated as to the function of the VRO and its components ,I'm afraid I can't speak intelligently about the reasons John/Rude would consider the no oil alarm an adequate warning to alert the operator in time before lack of lubrication became an issue.The introduction of the VRO was implimented to allow the engine to run with a more precise mix necessary under varying RPM situations and to create a more user friendly, no oil adding, hastle free design to entice consumers.The no oil warning alarm ,in my opinion,was less thought through on particular models,although needed. I ran my rig for 6 years with it in service and opted to bypass it and mix 50:1.As mentioned above ,if an individual carries out the routine maintenance this system requires to prevent catastrophic failure then he can gain some peace of mind.Fact is,if in the "remote" chance that the oil line was to become suddenly disconnected from the inlet,<br />of the VRO pump,for whatever reason, by the time the alarm sounded no oil,assuming it was working,your engine would be toast.From the years of my industrial experience ,this falls a bit short of a failsafe alarm design and I opted to eliminate this fraction of a chance from the equation on the advice from several iboat memebers and 3 local outboard mechanics.My particular application was a 96'70 hp Evinrude.Whew!<br />I hope you don't take this post as a personal attack ,but rather one that attempted to explain my point of view.
 

macojoe

Petty Officer 2nd Class
Joined
Oct 30, 2002
Messages
146
Re: Injection or Pre mix?

I am also installing a older Yamaha on my boat. It is 1990 175 Yamaha V6 I guess I will start pre mixing also. I no the injector was working when I bought it but not sure how well. I an't going to take any chance's<br />Macojoe
 

plugger

Petty Officer 3rd Class
Joined
May 28, 2002
Messages
75
Re: Injection or Pre mix?

Before reading this post i would have<br />never considered mix your own an option, next,.. its full to the brim<br />35 gal under deck.....i lift the feed hose out of the vro and what ....<br />take some gas out to make room <br />im suposed to do this at the gas dock<br />id be shot.... tying up the dock to measure it right\<br />ive only been in this a couple of years but ive never seen anyone other than a ski-doo stop and get the bottle out.ya got me interested enough to want this to work-out.....<br />how do the larger capasity guys handle this or are you taking 5 gal cans at a time ...not an option in my marina
 
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