Old/bad gas????

[SilverBack]

Has anyone ever had a problem with old or bad gas with a high horsepower engine? Did the engine idle ok? I am not talking about water in the gas or something like that just old gas that has lost it's mojo. How did the engine sound? What were your engine's symptoms? Did you loose a lot of horsepower?

[mrfixxall]

Has anyone ever had a problem with old or bad gas with a high horsepower engine? Did the engine idle ok? I am not talking about water in the gas or something like that just old gas that has lost it's mojo. How did the engine sound? What were your engine's symptoms? Did you loose a lot of horsepower?

The story ive heard is that the shelf life of gas is only a few months..try putting the correct amount of 105 octain boost in your tank and see if it runs any better...old gas will make your engine ping.

[The Hedgehog]

Unless properly stabilized, gas loses octane over time. I have seen some of these exact problems happen to a guy over here with his Baja. He had the old gas problem.

If you are using an expensive blown engine, you HAVE to use good gas. Most of us run most of the gas out before winter, stabilize the rest and then start out the new year with good prem (from a station that has a high turn over rate). Now that I am running higher boost, I will be throwing some race gas in for insurance purposes at the beginning of the year and during special times. Tex and I both are starting to buy Race gas in bulk.

I don't go overboard with it and know that my boat will actually get home with 87 but not on boost. I run around on 93.

You may be able to tune it for lower octane later if you have a low enough CR but when you are dialing it in good gas is a MUST. Remember, the boat loads the engine differently than the dyno. No matter how high of an X you have, you are swinging one big prop for those gears. Your setup would be like me trying to swing a 34 inch less prop on 200-250 less hp. That is a huge torque load.

I don't remember the MEFI 1 having a guardian mode but you may be driving the knock sensors crazy.

I would imagine that some of the serious tech folks on the site can tell you what you can get away with if you provide them some boost, static CR, timing and AF numbers.

Get it dialed in and then worry about trying to run cheap gas.

[DonziJon]

Won't idle after the winter storeage? Runs good above 2500 RPM? ETHANOL SUCKS. At the end of last season I had half a tank of 89 Octane in the Minx, gotten from New Hampshire...WITHOUT ETHANOL. I stored it Without any "Stabil" over the winter. Started it up last week on the third turn. Let me say it again...ETHANOL SUCKS. See below:

I have a 1990 Motorcycle that is rarely if ever ridden. Won't idle. Runs fine on the highway. It had 87 Octane with ETHANOL and Stabil in it for the winter. Won't IDLE. I've done everything short of yanking the carbs (4) out of it. :bonk: John

[MOP]

I would get it out and use it in your mowers ETC. There has been many discussions on octane boosters, most of which when it comes to modified engines is not a good way to go. Treat it right give it some fresh stuff.

Phil

[BigGrizzly]

It will knoch and loose upstairs rpms. Put the gas in your car and new in the boat. When I say old I mean 5 months.

[Last Real Texan]

Bad gas has caused many people to chase there tails for days on end only to find it was a simple fix by puting fresh gas in and having the problems they were having disappear. As we spoke on the phone I think this will help tremendously with you problem. Bad gas when run in a motor will cuase the motor to lose power up top and make the knock sensor go crazy, if the gas is as old as you say, more than 12 months, I will go out on a limb here and say this is a major cause of the lack of power you are experiencing....Keep us posted

Tex

[Donzi Vol]

Has anyone ever had a problem with old or bad gas with a high horsepower engine? Did the engine idle ok? I am not talking about water in the gas or something like that just old gas that has lost it's mojo. How did the engine sound? What were your engine's symptoms? Did you loose a lot of horsepower?

Get rid of the old gas, get rid of the old gas, get rid of the old gas! I just spent 3 weeks getting a motor to run right after putting the old/bad gas through it a couple times. I don't know how old yours is (mine was super old), but after a point of sitting it's only going to cause problems. Let me give a suggestion. If you have a friend that has an ex-wife, let him give it to her nephew to run in his truck. Nevermind how I came up with that :wink:. Oh, and did I mention to get rid of the old gas?

[DonziJon]

I guess i didn't make myself clear. My 1990 (1300cc Yamaha Venture Touring Bike w/31,000 miles on it) had its gas tank drained, and replaced the gas late last season... and again early this season with 92 Octane..(ETHANOL), that's all that's available around RI ...which it certainly does not normally need. I've used Carb/Injector Cleaner....Yada Yada Yada. I've drilled out the brass "seals" for the low speed jets and removed and cleaned them. They were not dirty. Still no joy. FRUSTRATED? You Bet. :bonk::bonk: John

[SilverBack]

Ok ..guys... I did not run the old gas by design. It was just a slip by my boat builder. The gas was put in the boat by the previous owner and I called him today and he said that it was from last September. I did take a bottle of sea foam, Lucas and 104+ octane boost with me when we ran the boat the other day. I have changed so many things that was the last thing on my mind. After the first run my blood pressure went so high I can't remember much after that.

When we got back to the shop we talked about draining the old gas and changing my old sending unit that had stopped working over the spring some time. I remembed to give David the fuel additives before I left.

The sending unit was changed today and the tank pumped out. David is going to get some new 93 octane and run the sea foam and lucas through it tomorrow. He is also going to take a 24 pitch prop and see how it sounds.

Thanks for all of the input guys...you guys are great help!!

[Donzi Vol]

The sending unit was changed today and the tank pumped out. David is going to get some new 93 octane and run the sea foam and lucas through it tomorrow. He is also going to take a 24 pitch prop and see how it sounds.

Good call. Now you'll have a fresh system.

[The Hedgehog]

Ok ..guys... I did not run the old gas by design. It was just a slip by my boat builder. The gas was put in the boat by the previous owner and I called him today and he said that it was from last September. I did take a bottle of sea foam, Lucas and 104+ octane boost with me when we ran the boat the other day. I have changed so many things that was the last thing on my mind. After the first run my blood pressure went so high I can't remember much after that.

When we got back to the shop we talked about draining the old gas and changing my old sending unit that had stopped working over the spring some time. I remembed to give David the fuel additives before I left.

The sending unit was changed today and the tank pumped out. David is going to get some new 93 octane and run the sea foam and lucas through it tomorrow. He is also going to take a 24 pitch prop and see how it sounds.

Thanks for all of the input guys...you guys are great help!!

Good idea. I also like the idea of throwing a relatively small prop on it to see what happens. It might not be the right prop but it will let the engine breath some.

FYI, don't rely on 104+ octane boost. It really does not do anything significant. I think a few others have mentioned that. He is right to get some new 93.

Clean gas and getting up in the boost will tell a bunch. I will keep my fingers crossed for you.

[yeller]

I'm actually surprised your boat would even run on that old fuel. I remember when I had my street bike. It wouldn't even start after storing for the winter unless I had fresh gas in it. I'm sure you'll see a big difference with the new fuel.

BTW, you could have put a gallon of that octane boost and you'd still have crappy gas. All the marketed octane boost stuff is a major scam.

[Lenny]

I had a full tank of 94 in my X-18 that sat in the shop for 2 years and two months. It ran perfect (Barry Grant 650, 350 MAG) Started perfect. Ran perfect. I have since run 3 more tanks through it. It was a non issue. 32 degrees total advance. Like I never blew the old motor up. Started INSTANTLY. The battery too, after two years and two months, (for whatever reason) was spinning like a banshee and lit the thing up first time a few weeks ago.

:) :) :)

No issues

[SilverBack]

Lenny..I am glad that you didn't have any trouble.

It turned out that my old gas was my problem. My boat idled fine but was not making power. It was making a popping noise at WOT. We changed the gas and it was like it was a whole different engine in the boat. The gas didn't smell bad but it was bad.