Mercury115 Inline-6 gremlins

[McGillicuddy]

Went down to the ramp to chase tuna but got no farther than the ramp. I couldn't get the old girl to idle.

Came home and got it to idle after 10 min of warm up but after a few gear engages I shut her down. Re-started and again had trouble getting down to idle. Yesterday I noticed fuel leaking out top carb but after shooting some carb cleaner in the dripping carb and giving it a couple of taps to see if floats were sticking or something, it quit leaking. Hoped it was fine. I thought I'd run it hard with some Quickleen today but never got off the trailer.

Any thoughts on the dripping(flooding) carb or why she won't idle?

Sticky float? gummed up carbs? where should I start? Thanks for any insight
I know these motors are sensitive to sitting too long or burning bad gas.

[Bushwacker]

Gillie, whenever my 115 V-4 wouldn't idle real well, one or more idle jets were plugged. Don't know what sort of carbs your I-6 has, but the V-4 has two 2bbl carbs that have brass plugs covering both the idle and high speed jets on both sides. All I had to do was pull the access plugs to spot the plugged jet, pull it, and clean it. No need to pull or disassemble the carbs. Typically was about a 10 minute fix.

You can prevent by always running the carbs dry after use, but I don't like running 2 strokes out of oil. In fact, I when I wasn't going to use the boat for more than a week or so, when flushing it I used to rev it up to about 1000 rpm and then kill it with choke to dump a bunch more oil in it. Not as good as fogging it, but maybe better than a normal shutdown. After I started using Stabil or equivalent, that seemed to reduce the frequency of clogged jets. However I never ran much ethanol gas thru that motor. I know it can raise hell with all the internal fuel lines downstream of the filter, so might need to change them if they aren't rated for ethanol fuel. Denny

[Fr. Frank]

I agree with Denny. Sounds like some dirt clogging jet or jets for the idle problem. As for the fuel running out of the front of the carb, same thing. The float-valve needs only a tiny spec of something to hold it open, and allow excess fuel to fill the carb and then run out the intake side. Unfortunately, to stop this, iff you haven't done it recently, you probably should pull and clean the carbs, replace all the fuel lines on the motor, and clean/rebuild the fuel pump. A real common problem is minute pieces of fuel lines coming loose from the action of the ethanol degrading the fuel line integrity, and becoming lodged in various locations where they imitate little monsters called gremlins.
I HIGHLY recommend the new marine version of STABIL made for use with ethanol fuels.

[gman1001]

Hey there, I JUST bought an 18' with the 89 Merc 6 cyl. motor. Runs strong but has the drippy carb thing going too. If you try the solutions provided and have success let us know!

Good luck.

[gofastsandman]

Gillie,
E 10 is also causing other problems. Does your needle valve have a rupper tip? If so, they may get soft and stick shut.Lean and mean is not good in this application.
The bowl gaskets are also swelling and hanging the floats open. Gas flowing under the cowl? Also bad. My carbs are plastic as is my vro pump and rubber lines etc.

I found a place to get non e10 90 octane locally and this may work in other places. I asked the assistant at the Buccaneer where they buy gas. Charles Brown oil co. I just
got my forms. Gated and pass card protected. Auto deduct weekly from my debit card. Gas is for recreational use only and costs the same as the corner BP.
GFS

[McGillicuddy]

Hi guys thanks for the input.

I finally got down to it and picked up some gaskets and valve seats to do the carbs.

First, I hate having to remove numerous shrouds to do a job. That is what I loved about my old Beetle and what I hate about my wife's Jetta.

Dang I-6 has more shrouds than Turin...just to remove a carb... 1.33+ shrouds per carbie

Anyway my symptom was inability to idle down to get into gear perhaps due to gas flooding from top carb...

Forced to remove my float bowl cover to get a wrench on the starboard carb mount bolts (damn! another shroud, or at least an impedance), there, in the top float bowl I believe found the culprit - a sunken float. Submerged and full of gas/oil it could not rise to cut off the gas flow. Went and fetched a float right before the dealer closed and got back to it.

I re-assembled in the dark and will give it a whirl tomorrow with fingers crossed. Didn't see any leftover parts so I hope I got all of the screws and bolts in their assigned places.

Question - is my logic sound? Would a drowned carb float cause such trauma?

Another question - is there a tool that will remove the starboard mounting carb bolts with out removing the float bowl cap - or is that by design because the bad float is a common problem?

Thanks again. I'll give an update tomorrow evening for the curious...

[Fr. Frank]

Forced to remove my float bowl cover to get a wrench on the starboard carb mount bolts (damn! another shroud, or at least an impedance), there, in the top float bowl I believe found the culprit - a sunken float.

That'll do it.

Didn't see any leftover parts

Always a good sign

Another question - is there a tool that will remove the starboard mounting carb bolts with out removing the float bowl cap...?

Yes, there is. It's an "thin-wall crows foot tubing wrench" socket wrench. I used to have a set of SAE sizes from Snap-On. 6 sockets cost me over $150 25 years ago. But the bad news is that you then have to remove all the fuel lines to use it properly because of the offset. Removing the float bowl cap is easier and faster.

[McGillicuddy]

Put carb float in ran it in a barrel and got it to idle pretty quickly, although rough. Probably need to scrub the lot of them, but hopefully I can slip out this weekend and run 20 or 30 gallons w/quickleen through her... I hear her beggin now...

Anyway, I'm concerned that while running in the barrel the intake was sucking up the napalm goo created by fuel/oil mix dripped into barrel. started foaming effluent out the exhaust... have I created a monster? or will a good salt water bath follow by rabbit ear flush clean out the water flow paths...the pyroclastic-looking flow scared the pee out of me.

[Fr. Frank]

Blowing all that goo out will be good for the motor. Take spare spark plugs with you, though. Really. All that carbon and congealed fuel mixed together just shows how rich you were running those 2 cylinders.

If you can find a source for Quicksilver "Power Tune" in bulk liquid form, adding it at a rate of 50:1 to your portable fuel tank (add the right amount of 2 stroke oil, too) and running it for an hour or so will clean varnish and goo from the fuel pump and carbs, and loosen and blow out any carbon in your motor, too. Your motor will smoke more than usual while running it.

I used to have a local source for that stuff, but he went under in this economy.

[nos3665]

If you can find a source for Quicksilver "Power Tune" in bulk liquid form,

[/QUOTE]

Never found any Dealer around me that sold it Bulk Just the cans, what size is the "bulk" pint. quart? or larger?