89 octane in 600's
 

Getting ready to deliver a new 382/600 boat.Buyer just found out no 91 octane available anywhere he boats, and he isn't buying a trailer. A couple of tech guys told him 89 wouldn't hurt it,just might not develop absolute full power. He isn't concerned about speed,just reliability and warranty .He is going to call Merc Racing for guidance. Depending on what they tell him,thr sale may go astray.Anyone have any good ideas?

Hey magicfloat I think 89 WILL hurt the motors. Get yourself to an auto parts store and pickup some octane boost supplement. Had a customer here that ran it for years in his 525/454 boat because there was no 91 available near his house. I believe there is a brand called 101 Octane Boost that works real well.

As with any EFI engine, they should have knock sensors that will detect whether or not timing needs to be backed off. Whether they can run continuously that way, I don't know. I've been running my 382 with Innovation 600's on 89 octane (92 recommended) for 8 years, and everything looked good when I opened them up this winter for valve springs, but those are injected 540's not supercharged 502's. I suspect there may be less tolerance in the Merc 600's, as they are being worked much harder, particularly from the viewpoint of gross hp per cubic inch.

Looks like I lost the sale,Merc told him no way,no additives,and no warranty. Sometimes I wish I had a son so I could forbid him to go into the boat business.Who would have expected this? When I bought Karen a new BMW M last year,they said it must use 91,no big deal,all land stations have 91,apparently many marinas up north don't.He already bought a new lift,new insurance,paid off the old boat,and closed on the loan,had a check waiting for me Tuesday.What a mess.

How about a tank at his house and have 91 delivered? Many of us that here in Virginia.

Don't give up, even if you have to be the one to make the calls to find a local fuel tanker. He doesn't even need to store it at the house, just pump it straight to the boat. LOTS of people down here in FL have tankers bring diesel and gas to their docks. Chances are, it'll be cheaper than a marina's prices.

Good luck.

I was thinking the same thing...I know "excursion" has a 500 gallon tank at his house and actually pays LESS for 93 octane gas then at the regular land stations....This might be a problem here since it would be placed next to the water...try this though and good luck getting it put together Robert.

Hey Robert.....sell him my 35 hour 540's (630HP) and put those 600's in my boat!!!! :)

I can understand why Mercury said no way at 89 octane as there is a liability issue concerning the warranty. IMHO, 89 Octane with a good octane boost should work. Torco Racing Fuels sells concentrated racing gas that they'll ship to your house. As for octane boost, Supreme 130 by Kemco is probably the best concentrated octane boost available. It's not cheap, but it works. www.kemcooil.com

Why don't you trade the 600s out for 525s from another in stock boat? You're saying he's not concerned about the speed and the 525s should be very respectable in the boat.