rec gas and mercruiser

[Jimwhall]

At the risk of opening up a potentially controversial topic, I'm wondering if rec gas can or should be used with the 4.3 L MPI Mercruiser.

I just got this boat, but all my previous boating experience was with two-stroke outboards. In my older outboards, switching to rec gas was a real game changer in terms of performance and easy starts. This is something I should consider for the 4.3?

 

[Texasmark]

Can of worms but I find gasoline filling stations around marinas and launch sites here in N. Texas.....HMMMM. Also today I stumbled across a New Sea Foam "Marine" grade fuel treatment. Lots of good things in the can application area. Bought some. I run gasoline in my current 2 stroker OB and in my non-computer farm gas engines.

There is a tutorial Faztbullet found concerning the two types of fuel whereby learned individuals in the fuel business commented on using either....I think its a sticky. Its in boats, or Merc engine repair section tutorials.

 

[Jimwhall]

Can of worms but I find gasoline filling stations around marinas and launch sites here in N. Texas.....HMMMM. Also today I stumbled across a New Sea Foam "Marine" grade fuel treatment. Lots of good things in the can application area. Bought some. I run gasoline in my current 2 stroker OB and in my non-computer farm gas engines.

There is a tutorial Faztbullet found concerning the two types of fuel whereby learned individuals in the fuel business commented on using either....I think its a sticky. Its in boats, or Merc engine repair section tutorials.

Can you run rec gas in a mercruiser

 

[Texasmark]

I ran regular gasoline in my Mercruiser when I had one. If I had one today and did the family out on Sunday afternoon thing with water toys and all and used the boat frequently E10 wouldn't bother me a bit and probably no additives other than a little injector cleaner now and then like I do in my P/U.

 

[Chris1956]

According to Wikipedia, Rec gas is alcohol free 90 octane, unleaded fuel. If so, it is fine to run in your 4.3 V6. I would not expect any additional performance out of the motor, without modifications.

You might be able to modify the ignition system to advance the timing, however, since the ignition is electronic advance, I am not sure how to do it.

You might repost this in MerCruiser forum. If anybody knows the answer, it will be them.

 

[Jimwhall]

I mainly going for ease of starting. As I said, it made lifetime of difference with my old two-stroke outpoured. But it sounds like it might not be as big of a deal with a four stroke 4.3 L

 

[Chris1956]

A MPI Mercruiser 4.3 should start easy. You have other issues, I will guess.

Repost that in MerCruiser forum for correct fix.

 

[Jimwhall]

I am not having any issues. The engine is new to me. Just trying to figure out what is the best fuel to use