Honda 90 - water in gas?

vikingham

Cadet
Joined
Aug 19, 2005
Messages
29
My '98 Honda 90 ran great at the start of the year, and it still seems OK above about 1500rpm or so, but the last two or three times we've been out, it's been rough at idle and at low speed (say, 1000rpm and below). It's gotten increasingly bad each time; tonight we took a little sunset run, and I ran it up to WOT several times for a minute or so to see if that would help clean things out. It seemed to rev up smoothly; when it returned to idle after running fast it was smooth, but after heading back in at slow speed, it started vibrating quite a bit going through the marina, and then stalled at idle after we tied up.

Here's some background:

-- The fuel in the tank is old - put in last October, with fuel stabilizer added then (but not since). It's a 48-gallon tank, which I filled before winter storage; we've not been able to put a lot of hours on the boat this year, with a couple two-week gaps in usage, so we still have about 14-15 gallons of the old fuel. I haven't wanted to fill the tank until we ran it down further, because of all the troubles people have had mixing old gas with the ethanol stuff.

-- I took off my fuel filter (a Sierra) this evening and poured the contents into a glass container; there was about a quarter-inch of water on top of maybe 2 inches of gas. The fuel filter was new this season, as was the fuel line and primer bulb.

-- The carbs were cleaned and synched last year, and drained properly for the winter.

-- I tried pumping the fuel bulb while the engine was idling rough, and it didn't help, so I don't think it's starving for fuel. Also tried pumping it with the engine shut off, and no fuel leaked out of any carbs, so I don't think there's a stuck float.

I'm thinking it would make sense to try running the engine off a different gas supply. I don't currently have a portable tank, but I do have a two-gallon gas can....would it be OK to just stick the fuel line in there?

And/or - would it be worth trying to top up the tank with new gas? I'd have about a 2:1 ratio of new gas to old gas; I've read that it's best to have a 4:1 ratio to avoid problems with the new ethanol formulas.

Many thanks for any advice - and I know that using the boat more would be good, for lots of reasons....if anyone has a solution to work, family needs, and lots of rain let me know!
 

DHPMARINE

Captain
Joined
Dec 16, 2003
Messages
3,688
Re: Honda 90 - water in gas?

Usually (all the time)the stuff on the bottom is the water.It has a specific gravity heavier than gas.Same with motor oil and gear oil.H20 on the bottom.

You need to flush the tank after draining,and if the carbs can't be drained and flushed,rebuild them.

DHP
 
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