87, 89, 93 octane

[pursuit2460]

I have a 93 johnson 225. What is the octane I should be running. 87-89-93. thanks

 

[tashasdaddy]

Re: 87, 89, 93 octane

87 imho, & tcw3

 

[JB]

Re: 87, 89, 93 octane

What Daddy said.

 

[Dhadley]

Re: 87, 89, 93 octane

As long as your running it stock, as produced, 87. If youre running small bore heads, 93.

 

[pursuit2460]

Re: 87, 89, 93 octane

Well I bought the boat used 4 years ago it was and ex-marine patrol boat. I dont know what small bore head are but thanks for the info.

 

[budsbud66]

Re: 87, 89, 93 octane

the only real way to tell is to warm the motor and do a compression test. that way we can pinpoint what you need.

 

[Dhadley]

Re: 87, 89, 93 octane

Whats the casting number on the heads? I doubt seriously that the Marine Patrol changed the heads.

 

[2even]

Re: 87, 89, 93 octane

Dhadley, which motors have small bore heads that would fit his motor. Or are you refering to 150-175 heads and what is the advantage.

 

[pursuit2460]

Re: 87, 89, 93 octane

the # on the heads are 340839 also comp. is 100-95 on all pistons

 

[Dhadley]

Re: 87, 89, 93 octane

On the big bore 3.0 liter V6 loopers (1988 & newer) we run the 2.7 heads (1986 & 87) to gain power. But at that point we run 93 octane. It shows up best on performance type boats.<br /><br />You have a Scarab, right? It may help but I don't think the gain would offset the trouble & $$$ of putting 93 octane in that big of a tank.

 

[2even]

Re: 87, 89, 93 octane

Dhadley, thanks for the reply. It was only for info that I asked the question, you are correct about the tank !!!. By the way con-grats on your 10K post, I also thank you for your contributions.

 

[Dhadley]

Re: 87, 89, 93 octane

Thanks 2even!

 

[1ncornett]

Re: 87, 89, 93 octane

i have a j60tletd and thought to always put 93 octane. now that i've read this post, i'm questioning that. which octane for my motor?<br /><br />thanks for your input.

 

[1ncornett]

Re: 87, 89, 93 octane

bump

 

[Dhadley]

Re: 87, 89, 93 octane

87 is better for your motor too 1.

 

[pursuit2460]

Re: 87, 89, 93 octane

Any info on my head numbers and what octane to use.

 

[1ncornett]

Re: 87, 89, 93 octane

thanks, dhadley.

 

[Dhadley]

Re: 87, 89, 93 octane

Those are stock heads AJ. 87 is fine.