Got my first tank of E10 gas this weekend

[Jackman]

Well, after a bunch of odds and ends, setting my timing to 30degrees advanace at 3200rpms I took the boat over to the dock to fuel since she needed it. Once fueled up I headed out and made it about 300yrds from my marina entrance and heard backfiring though the carb. I immediately put them in neutral and anchored. Idled perfectly and checked timing...decided to put it back to 10 degrees and stumbled back to the dock. Once there I emptied my water seperators and found really bad fuel. Emptied the filters and filled with new fuel..put a new sets of racors on as well. Once primed the engines turned over perfectly but once I hit the water I had back firing again and this time the engines shut down and did not want to start again. Luckily I brought a container so emptied the filtered and found them loaded with dirty fuel and water again. Primed the engines and went back to the dock once they started.

I remembered that last year I had a plug fowling problem so I pulled the plugs. Sure enough they were very black as though I was too rich or the plugs weren't hot enough. I got new plugs for both engines (installed plugs with a higher heat level of 12)gapped them at 0.035 and installed them. Took her for a ride...no poppin through the carb anymore but shut off again because of water.

My question is.....once I get all of the water out of the tank from this ethanol gas and she runs okay at 10deg timing should I set the advance at 30degs at 3200rpms to get my top end and figure the backfiring was from extremely fouled plugs? Is it okay to go from a plug of heat level 8 to a level of 12 without a problem? My crusader manual specifies 8 but all part stores specify 12 in their marine catalogs. They don't even list an 8 for 1985 crusader 454s...just a plug of heat level 12.

One more thing...my machinist put the engines together last year with intake gaskets that don't have a blockoff plate for the exhaust cross over. Is it a must that this blockoff plate be there in a marine application?

Thanks,

Jack

[SeaEric]

I'm not a mechanic and I do not pretend to know what I'm talking about on this subject. That said, I had a customer 2 years ago whom I'm told, changed to "hotter" plugs in a pair of 350ci/270HP Crusaders. He ruined the engines in a matter of 2 hours running time and had to replace them. I don't know details, only what the yard owner told me about why the repowering job.

[UNIQUE_NAME]

i hate to be the bearer of bad news, but E10 is not like your fathers gas.
with real gas water sat on the bottom, when you pumped it out the remaining fuel was good to go. with E10 the water still goes to the bottom but it will take the ethanol with it. it is called phase seperation. you can pump it out but the remaining "gas" is low octane maybe good for your lawn mower stuff. from your post it appears you are pulling quarts of water out of the tank. before you worry about plug/timing you may want to address the fuel issue first.

jim

[Jackman]

Well if that's the case I can approximate and add some straight ethanol to make up for it...But I'm not. I'm just going to siphon out the bad stuff, add some fresh and burn all of it.

[67hat34c]

what about adding octane booster instead of more alcohol

[Jackman]

Maybe adding a case of my favorite beer would work too! (Just some humor in lieu of this tragedy)

[Karl]

Read this: http://www.boatus.com/news/e10_0706.htm