350 Horizon Mercruiser additive problem

[aviatorcg]

Help! I have twin Horizon inboards on my pursuit that up until a few weeks ago were bulletproof. I filled up my tanks, and without paying attention I added the blue enzyme additive instead of the red stabil I always use. Boat ran fine all weekend. The next time I went out (2 weeks later) the boat wouldnt reach full rpm despite WOT position. It hit about 2000 rpm. For reference I usually run about 3200-3400, WOT is close to 5000. They both ran fine in idle.

I checked out the WOT thread on the Adults Only section and have ensured the bottom is clean, replaced the fuel filters, checked the fuel pressure, and all the other obvious things on the list.

Both engines run identical and there is no common connection other than the fuel - separate tanks, throttles, transmissions, etc.

Could the Blue additive have screwed me over? I have about 1/3 tank in each tank. Should I just fill up the tanks and add an octane booster and see if that works?

Any advice would be great.

Thanks.

 

[mkast]

Re: 350 Horizon Mercruiser additive problem

What is blue enzyme additive ?

 

[aviatorcg]

Re: 350 Horizon Mercruiser additive problem

Good question. When I was filling up the boat I asked for some Stabil. The guy running the pump brought out a bottle that looked like stabil but was blue. I dont remember the exact label but I asked him if it was the same - (it was hot and I was in a hurry). He said yeah. Since the problem occurred, I called the marina to ask about it and they told me it was an enzyme tank cleaner I dont know the exact brand name but from my on line searches it seems like the same thing. Any ideas?

 

[mkast]

Re: 350 Horizon Mercruiser additive problem

Read the label. I know you don't have it, get another bottle to read. The more information you can provide, the better the solution will be.
How much of the additive with how much fuel (dilution)?