Is ethanol a problem with a 1983 3.7 470

[artificialreef]

Hi folks, i finally got my twins running smooth and reliably after 4 years in dry dock (the boat has never seen the water since i bought her). They are 1983 vintage 3.7 470's with an alt and 4 inch heat exchanger conversion. Quick couple of questions. Since these are pretty basic auto type motors carbed do you folks think the 10% ethanol from pump gas would be a problem down the road. The only rubber i think it would come in contact with is the fuel line from the tank (and pickup)which i replaced. The diaphram in the fuel pump and the carb internals. I rebuilt the carbs so the only weak link i see is the diaphram in the original fuel pump and maybe the pickup in the tank. I know outboards are taking a beating from the ethanol mix but i dont see it being a problem for us na motors. (1)What do you guys think?
I see some fuel pump rebuild kits for these and hope they have been upgraded to ethanol tolerant. (2)Anyone rebuild a fuel pump and know if they are ethanol compliant, (part number of the good kit?).
Lastly. I have never been a captain of a vessel except on those pesky jet ski's. I am going to take a power squadron class offered locally here in Stuart fl, I know i can ask it in the class but just curios.(3) Am i supposed to run my blower all the time while under way or just before starting? I want to thank all of you on this forum and Iboats for getting me where i am. This resurrection has been quite an undertaking but i am almost on the water. A special posthumously thanks to Don. I just caught wind of his passing last week and know he will be dearly missed. He was a great man.
Thanks.

 

[oldjeep]

Re: Is ethanol a problem with a 1983 3.7 470

If you have never run ethanol, your biggest problem will be how quick it cleans all the crap out of your fuel system. Buy a couple extra filters and be ready to change them.

Once you get the 30 years of accumulated crap out of the fuel system then you'll never have to clean it again.

 

[Another retired guy]

Re: Is ethanol a problem with a 1983 3.7 470

Are you saying that ethanol fuel has never been used? What is the fuel tank made of? If it's fiberglass, ethanol can "soften" it.
Blower should be run for four minutes before starting the engine, AND whenever you are traveling at no-wake speeds. When cruising, the vents will keep the air moving through the engine bay.
Develop the habit of checking the engine bay both before and after every run. Check for leaks and gas fumes!

 

[Eric 3.7LX Alpha 1]

Re: Is ethanol a problem with a 1983 3.7 470

Myself.... I haven't had any issues. I add the marine stabilizer to the tank before filling, and so far so good.

Let's get those girls singing in the water!!

I will second the thanks to Don. Hope he's on the water somewhere right now as we read this!

 

[artificialreef]

Re: Is ethanol a problem with a 1983 3.7 470

Fuel tank is aluminum and looks brand new. Inside may be another story but i will deal with that when i leave the remote tank tether. I have been using ethanol (with stabilizer) since i started working on this 3+ years ago and they both now run like new motors. Just didnt want to be off shore and have a catastrophic failure due to some plastic melting that i overlooked. Thanks again friends. I can not express how much help you have been. I work for the state of florida on a mediocre income and could never have afforded to been a boater with out your help.
Note to new to you old boat buyers. I did a compression test before i bought this boat that the man in possesion of the boat said it had been stored, sitting in his yard and not started for over 2 years. When buying a new to you boat. First thing to do before buying is a compression test (i even asked the guy storing it if he had an air compressor so i could blow out all the debris that settled into the spark plug valleys before i pulled the plugs, so it wouldnt fall into the cylinders and he complied and said he was impressed). Second after purchase is change the impeller. I started one motor not knowing anything about io's and watched the temp climb to 150, then 160, then 165 and i shut her down. Found a donught where the impeller was supposed to be. These 470's love to blow a gasket (they both now idle at about 145-150 degrees). Thank goodness i was coherent enough (and am a half decent shade tree auto mech) to realize what was going on. I see alot of folks get hosed by buying what looked like a clean boat only to have the motor be toast.

 

[cr2k]

Re: Is ethanol a problem with a 1983 3.7 470

A 470 is enough problem on it's own.

 

[artificialreef]

Re: Is ethanol a problem with a 1983 3.7 470

I dont think you are correct cr2K. They are both running smooth and cool. I have the alt conversion and the 4 inch heat exchangers. The only thing i havent fixed was the cam water pump thingy because it hasnt presented itself yet. When these are taken care of they have great gas mileage and super torque. You just cant be afraid of them and have to somewhat know how to tune a motor and turn a wrench. You are officially banned from the 3.7 club. Just funnin you cr2k.

 

[GA_Boater]

Re: Is ethanol a problem with a 1983 3.7 470

You are officially banned from the 3.7 club.

That's funny, AR. 470s are like any marine motor, actually any motor. Some have some correctable flaws and once fixed and the good ones will turn to junk if you don't maintain them. And I mean any motor, not just 470s. For some reason many owners neglect their boats, including the power systems. I guess they don't use them enough.

On to your questions and my opinions:

1) No, go ahead use E10. Do change the filters and keep some on hand because it does tend to clean the tank out. E10 and 470s seem to have the same rep. :facepalm:

2) I don't honestly know about 470 fuel pumps since Merc hasn't made them in a while. I'll say this though. I rebuilt my fuel pump in my outboard 2 years ago from the original Merc diaphragm (45 years old). I opened up the pump a couple of weeks ago working on a fuel problem. I ended up putting the original "old" diaphragm back in because it was in better shape than the "new" one. Just my experience, nothing to swear by. I tend to hang on to some replaced parts for emergency spares.

3) Run the blower after refueling for about 5 minutes after opening the hatches and sniffing. Also run it when running at lower speeds because may not be moving fast enough to do the purging. Probably a good habit to run the blower before any warm restart.

I hope that helps you some. Get that gal on the water after taking the PS course, a great plan in itself. You will learn a lot and get many questions answered.