I think I screwed up-UPDATE!!

[woodnknots]

Let me start by saying that I had my boat in the water a couple of nights ago, and all was well.
So today I put new plugs in (NGK's) because I ran a tank of seafoam through.
I started the motor and all was well for several minutes before I shut it off.
I went and got gas.... and this is where I think I screwed up. The pump I went to was out of 87 (my usual octane) so I went with 89. Filled it up, mixed in the oil (50:1) and went to the water. It started up and warmed up fine, got out about 100 yards into the river and opened it up. It ran fine for a few seconds, then just died. I gave it a few seconds, and tried again. It started, then ran for a few seconds, and died again.
I figured, "you idiot, you shouldn't have changed the plugs!!", so I put the old plugs back in. Same scenario. It started, but would quit just like it ran out of gas.

So I started looking at worse case scenarios, like fuel pump, clogged jets, etc... And then I remembered the octane change.

I called my buddy who has some experience with outboards, and he thinks that the octane change conflicted with my timing, and when the engine ran for a few seconds and got to temperature, the time gets progressively worse till it just quits.

This sounds right to me, but what do I know? Can anyone shed any light? I'm draining fuel right now.

Thanks,
Dave

See last post for latest information. Bad things happened...

 

[i386]

Re: I think I screwed up

Re: I think I screwed up

I wouldn't panic just yet. Put the correct fuel in and see how she runs.

 

[eurolarva]

Re: I think I screwed up

Re: I think I screwed up

I doubt 92 octane is going to cause you grief. If this is marina gas it could be just nasty gas. Could have water or is old and going stale. How much of this gas do you have? Inboard tank or portable? If you have access to a carb remove the float bowl and pour the gas into a mason jar and have a look and see if water is present. You may just need an inline filter.

 

[roscoe]

Re: I think I screwed up

Re: I think I screwed up

I'm with eurolarva, most likely bad gas.
Change the fuel filter and flush out the tank real well.

Higher octane fuel won't cause this to happen.
It's a waste of money for a 2 cycle, and can lead to some problems with long term use, but it won't kill your motor like this.

I have used all grades of gas, with all combinations of additives, from the USA and Canada, and have never had this happen.


Let us know what you find.

 

[woodnknots]

Re: I think I screwed up

Re: I think I screwed up

okay, so, today I got new gas (87 octane from another station) and all seems well on the muffs. I ran it for several minutes at a time from low range to mid range several times. I am going to try it on the water here shortly.

The theory of bad gas (oldish, maybe) seems to be holding up. I put 89 in it, and that is an octane that the gas station is NEVER out of, probably due to the fact that, with gas prices, 87 is just more economical to use. The 89 octane was sitting for who knows how long before I got to it. Probably had moisture in it.

Anywho, the motor seems to run okay, better even than it did before the seafoam and new plugs (go figure). We'll see how it performs on the water!

Thanks for all the help!
Dave

 

[woodnknots]

Re: I think I screwed up

Re: I think I screwed up

Well, I didn't take it out last night, but I am taking it out tonight. I went and filled up, then ran the motor for about 10 minutes through all the range I could get on the muffs, then a little bit more. All seems well. will post more tomorrow, or later tonight, depending on what time I get in.

Dave

 

[woodnknots]

Re: I think I screwed up-UPDATE!!

UPDATE!!

Okay, the gas problem is solved. I got it on the water, and it stayed running.... good news.

Bad news, I lost cylinder 3. No spark. 1 and 2 had good spark. Got home, figured it'd be a coil, no such luck. After moving coils around to known good CD box wires, I got spark on 3. Initially I had moved the coil from 3 to 1 and vice versus, and tried it, expecting to have a good spark at 1 and not at 3 (I suspected the coil to be the problem). I got good spark at 3, telling me the coil was good. I then suspected the CD box. I swapped boxes, and got good spark at 3. I didn't pysically move the boxes, I just moved coil wires.
What is involved in changing a CD box, and are they expensive? I have a marine salvage about 40 minutes from my house, I'll probably call them tomorrow.

 

[roscoe]

Re: I think I screwed up-UPDATE!!

Ok, here is possibly a bit of good news for you.

You have a 90hp 3 cylinder, correct?

Each cd module has outputs for 2 cylinders.
So you have a total of 4 outputs and you only need 3.
Sometimes only one output on a cd goes bad, and the other output is still functional.

You already know which output is bad, so try using the other 3.

Replacements are available from strandardmagneto.com
or from maxrules.com

 

[woodnknots]

Re: I think I screwed up-UPDATE!!

Ok, here is possibly a bit of good news for you.

You have a 90hp 3 cylinder, correct?

Each cd module has outputs for 2 cylinders.
So you have a total of 4 outputs and you only need 3.
Sometimes only one output on a cd goes bad, and the other output is still functional.

You already know which output is bad, so try using the other 3.

Replacements are available from strandardmagneto.com
or from maxrules.com

Unfortunately, I already tried the other output. Both are bad. Thanks for the websites!! $100 is alot better than $330 any day of the week!!