1979 115 Mercury

" Lots of troubles... This en

" Lots of troubles... This engine sank. I pulled it up, took the plugs out and spun the engine with the fuel line connected for about 3 or 4 minutes. Then I squirted a little oil into each cylinder until I could get it home to work on it.
I cleaned all carbs, thoroughly. She's running fairly well in idle, but when I give it the gas she revs a little but wont pickup. Like its bogging. I replaced the fuel line. Float adjustment maybe?

This engine was running pretty good before it sank. I did have trouble with it on top end (nothing like now), carried to mechanic and he said it needed re-wiring - fire popping under the hood. I replaced all of the little wires under the hood before it sank.
Any suggestions on the bogging issue? I know it can be anything after being under water.

By the way, still dont know what caused it to sink. It was anchored, the plug in. I pulled it to the bank, dipped the water out, floated it across the pond to the landing and it sat several days in the water, no water inside the boat. Beats all I ever seen. "

" Have you tried adjusting the

" Have you tried adjusting the carbs a bit? Usually after rebuilding carbs you start at 1.5 turns and begin adjusting from there.. Did you adjust them? If they have been completely disassembled, cleaned, & rebuilt, and adjusted - back each low speed jet out 1/8 of a turn and see if anything changes. Try it again if neccesary.

I don't think it has anything to do with the float adjustment - that would either allow the carbs to flood and spill over or would cause a lack of flow altogether, making it run really bad. All three carbs shouldn't have become unadjusted either.

Be sure you didn't screw up the sync between carbs & the sync between spark advance & throttle. It's possible to mess this up when pulling the carbs off if you go the wrong route.

For the heck of it, look down underneath the black boxes in the cowel - see if the vacume hose that enters there is on it's fitting. I swear when I put mine back on it ran better..

Is it bogging or doing something else at high speed? Is it intermittant or constant?.. Check for strong spark on all cylinders.

Another idea - does that have an enricher valve for the choke?.. If so, and you haven't drained it, it could be filled with water - you could've re-contaminated the carbs. Water will clog carbs -it doesn't move through them like fuel. Also be sure to drain every one of the fuel and vacume lines between the carbs.

Normally, imeadiatly after an engine is submerged, the powerhead must be completely disassembled, cleaned, dried, oiled and then rebuilt. Every ounce of water has to be taken off the electrical parts. Even if it runs well now, it could have begun to rust inside & may stick later. The biggest problem is probably the crank & bearings - you get pits from things sitting in one place with moisture. Rings will rust, but do not require the same degree of precision as bearings & won't hold moisture the same way.

Best of luck,

Jon "

" Thanks, I'll check thos

" Thanks, I'll check those things. It idles pretty well, when I give it the gas it picks up a little and holds there, doesnt drop off or pick up. One time while turning in tried to rev up for a second and died right back to where it was.

My bottom 2 carbs were flooding. I adjusted the float tab just a hair to stop the flooding. I have ordered new needle/seats and floats and will adjust correctly. Just ahted to buy those until I felt like they may be the problem.

The sync between the carbs, whats the proper method to sync them up? I guess you're talking about the throttle links.

Also dont you need to sync the air screws by going in our out until it misses, back the other way until it misses and then half way between? I may be wrong on that, but I do recall doing that on somthing before.

I'll check the vaccum hose, if I can find it.

I dont know about the enricher valve, but I dont think it does. I'll look closer tonight. Its a electric choke of course and I dont recall any adjustments other than the air jet.

Thanks for insight, I'll let you know the results of my findings.

I am aware of the water, I hope to get it running to usable and run it as long as it will.

What about the fuel pump? What kind of affect would it have on my issue. "

" The hose isn't a vacume

" The hose isn't a vacume hose, it's a bleed system hose that lubricates the lower crank bearing. I think it might affect crankcase pressure if missing, it seemed mine hesitated less after fixing it - not sure why completely though..

The enricher valve is what the electric choke is accomplished by - it's a little solenoid looking thing w/ a fuel input & output. It injects the
crankcase or reeds or carbs (I forget which) w/ fuel. Look for the fuel input/output from the odd little cylinder - if it's there, you will find it.

The fuel pump should probably be rebuilt, and it's cheap enough so you may as well get the kit & do it right. Be carefull though - the pump is made of quite a few gaskets & parts that could be easily switched in order - pull the bolts out & carefully take the whole stack of junk off as an assembly. Then get yourself some nice clean space & build/clean the new one as you disassemble the old.

As for the carbs; When you clean/rebuild carbs you have to actually take those screws out. I assumed because you said you cleaned them that you had
completely disassembled, cleaned, and rebuilt them, and then had allready adjusted the screws. That's would be where I would start - get 3 carb rebuild kits & carefully (I'd do it one at a time to be sure I had a working example left) dissamble, clean & rebuild those carbs.

Put the new adjusting screws/springs in & slowly bring them in until they barely touch (don't force them down else it wrecks the point). Back them each out 1.5 turns. Put the carbs back on etc.. I do all carbs at once - have never been able to figure out how to do it correctly one at a time. You need to adjust the idle & mix at the same time.

Here's Joes method, this is for 1 carb, I'd do them each the same & then make fine adjustments later if the plugs show differences.

Gently seat that slow speed needle valve, then back it out one and one half (1-1/2) turn. Start the engine and set the throttle to where the engine will just stay running (it's going to run lousy). In segments of 1/8 turn, start turning that s/s needle valve in. Wait for the engine to respond after each 1/8 turn. As the rpms increase (and they will), adjust the throttle again to where the engine just stays running. You will reach a point where the engine will either start to die out of it will "cough/spit back". At that point, back the needle valve out 1/4 turn. At some area in that 1/4 turn, you'll find the smoothest setting. Good Luck.

There's another procedure for getting link/sync right - and yes, I did mean the linkage. You'll need a repair manual for a good description. For starters though, be sure the carbs open and close in unison, it's easy to mess that up & it will matter.

Those needles are low-speed adjustment. Lean low speed settings will make an engine idle nice, but hesitate on it's way to higher RPM.. That's why I said backing them out might help, it brings it more fuel.

Jon "

" Thanks Jon..
I feel like it

" Thanks Jon..
I feel like its fuel related.. I'll try the method you metnioned until my manual arrives.. Can I make those adjustments in the yard with water hose, or do I need to be in the water for backpressure?

I found one hose just behind the carbs (besides the fuel line) and one behind the electronic plate (looked like vaccumm, not sure). Both were connected and neither had oil or anything on them to represent a leaking line.

I'll try the rebuild (this time with new parts) and the fuel pump and let you know. Thanks again for your help. "

" You can make initial adjustm

" You can make initial adjustments w/ the flush attachment, but you will want it in the water w/ back-pressure to properly set the idle (it idles higher on the flush) and to actually test it out. Two things tend to go wrong when you make adjustments:

The first is that it will idle great, but bog when you go to accelerate - this means the setting is a bit lean. Bring each adjusting screw out 1/8 of a turn and see how it goes, then repeat if neccesary. As a hack, the general rule I follow is rich is better than lean - the richer, the more lubrication. The kicker is that these engines idle better lean & run better rich, so it's a trade off. Don't be surpised if where you end up is not the optimum idle.

The second problem is as you adjust fuel/air mix, the idle will change. Leaner is a higher idle, richer is a lower idle, generally. So, when you richen the mix, the RPM's will drop a bit - time to adjust idle etc.. Along these same lines, when I adjust the idle on the flush attachment, it almost allways is too low, even if I account for it. When I go to put it in gear in the water, it will just stall every time. Looks bad, but it tends to be just the idle.

In the end you want to be able to accelerate without hesitation, idle in neutral without stalling (when warm), and it should idle somewhere around 800 RPM in gear.

Jon "