Need help with a fuel issue

[trooper1822]

Hello all, been gone for a while but am back and need some advice on where to go next. So I picked up bayliner trophy with a 1988 force 85 on it for 500 bucks. Guy I got it from had not run it in about a year. So did a bunch of restoration on the boat and today was the day to start it. Ran it from a gas can and after about 10 min was able to get it running. Runs fine and idles good. Ran it up in both forward and reverse. Issue is that when I run it fuel leaks from all 3 carbs. And it is leaking from multiple locations on the carbs. Also when I pump the bulb it gets hard but then eventually goes soft. So before I go and spend 60 plus on carb rebuild kits should I try taking them apart and cleaning everything first? If I need to buy carb kits what would be good ones to buy? Thanks in advance.

 

[roscoe]

I would stick with a factory rebuild kit from any Mercury dealer. Part number will start with "F" or "FK".

You could try cleaning.
Or replace float/needle kit $9. times 3 of course.
Or do a complete rebuild kit, $30 times 3.

It depends on how much your time is worth to you, and if you want to do it 1 2 or 3 times.

Bulb going flat is a different issue.
Fuel lines from tank pick up screen, to fuel pump.

You should probably rebuild the fuel pump as well, also best to buy a genuine Mercury part, about $20.

 

[jerryjerry05]

Yup don't spend any $$ yet.
Take them apart and see what's clogging the system.
The float bowl has a cork gasket and if it doesn't come apart in pieces when you remove the bowls? then just leave it alone.
Spray with WD-40 or something similar on the cork and let it set.
It will soak some oil and be able to re-seal.

I use Dawn soap and hot water then rinse with cold water and use compressed air to dry.
If your going to put them right back on, then leave them dry.

You might need a spray cleaner if the gunk deposits are real bad.

When you remove the air screw(top front) remember how many turns out to replace them.

The floats: it's best to reuse them.
The replacements are usually JUNK.

 

[trooper1822]

Thank you for the replys. So I took one of the bowls off and the seal on it came off in pieces. So ordered new seals and am going to clean everything and put it back on the boat and see honor runs. Another question I have is the motor does not have a overheat alarm on it. So what would be my options to monitor running temps? I would much rather have a gauge vs an alarm because in my opinion, by the time an alarm goes off damage to the motor would most likely already be happening. Is there a good kit that I could install? Thanks

 

[jerryjerry05]

Your alarm would probably be under the dash near the gauges??
Try shorting the orange lead(ley on) that connects on the buss bar on the stbd. side of the motor.
Ground it against the block or use a piece of wire???
The horn is pretty weak.
I remove them and replace with a car motorcycle horn.
If you replace: the horn needs to be wired right or it won't work??

Gauge vs. horn: you don't usually monitor a gauge as you go out boating.
I'd get sea sick if I did?
A LOUD horn is way better.
It's designed to go off before any real damage is done.

 

[trooper1822]

Update. So took the carbs apart and cleaned them. Found a lot of gunk in them and one of the needles was badly corroded so I replaced all 3 needles and seals. Put it all back together and the boat fired up off of a gas can (not using the fuel tank until I can clean it.) Now the new issues. So the motor is hard to start. It takes a lot of turns from the key to get it to fire. Once it does fire it is a pain to keep running. Sometimes it will idle fine for a few min and then just cut out. Does not give a hint it is about to die, just cuts out. And if I start it and put it in gear it runs and dosnt die but does cut in and out almost like it is starving for fuel.

so what I have done, took off the line going from the fuel pump to the carbs and hooked up a different line. Ran the motor with the line in a bottle and observed fuel spraying into the bottle.

next took the fuel pump apart and inspected the diaphragm. Looked good but I have another one I am going to put on. Next looked under the diaphragm and found a lot of varnish and crud. The valves looked horrible so I pulled 2 of them out but the 3rd is recessed in and is a pain to get out. Now 2 of the valves look the same with kinda like a metal tower over them, but the 3rd that is recessed in is just flat, is this correct? Also in the parts diagram it shows there should be a rubber o-ring but there was none when I took it apart. Where does it go and should there be one on all 3 valves? I want to order the parts but not sure on everything I should order.

SO anything else I should check/try? Won't be able to start it again until the new parts for the pump come in.

 

[trooper1822]

Oh and forget to mention, I did a compression test and got the following:

cyl1-125
cyl2-127
cyl3-125

so great compression on the motor.

 

[jerryjerry05]

The seal or gasket: there is only one.
The valves hardly ever go bad.
I've seen only one go bad??
It came apart and was it didn't affect the operation at all?

Find a parts diagram boatsdotnet has a good one.

The stalling and poor running.
What did you set the air screws at?
The 3 cyl should be set at 1 1/8 turn out and left there.
Some run great at that setting, some need to be turned out more.

Set the idle at 1100-1200 in the driveway.
750-800 in gear in the water.

 

[trooper1822]

Sorry, meant the seal. I'm assuming based off the diagram it only goes on the center valve, the one held in with 2 screws?One valve came apart trying to get it out. The other is recessed deep in and is going to be a pain to get out. I have not messed with the mixture screws but will. So I should start with the top carb, close it until just seated, turn 1 1/8 and listen if the Engine revs up. Turn until it starts to rev and lean out, then turn back until it starts to go rich and die out. At that point devide the two points and set it the middle. Then repeat for other two carbs?

 

[trooper1822]

Is this where the seal goes on this valve or should one go on each valve?

 

[jerryjerry05]

Only one seal.
Yes it goes in the center one where the screws hold it in place.

 

[trooper1822]

Awesome thanks. While waiting for the parts to come in I went ahead and checked to see where the timing was at. At TDC this is where my mark lined up. I'm thinking I'm having a fuel delivery issue. Last time I can it I noticed if I pushed in the choke while running it would idle up and keep running but the. Would drop off. I'm going to pull the carbs and re-clean them and also place a filter between the fuel pump and carb. I also noticed the last time they were apart that the float hight looked off. Is it supposed to be flush with the carb? Also going to try pulling the plugs while running and see if it changes the way ot runs. When I had the plugs out they looked fine but had some corrosion on them so I will go ahead and replace. Also going to get a big plastic drum to run it on instead of the muffs.

 

[trooper1822]

Did more digging when I got home and found that all 3 carbs mixture screws were less than half a turn out from seated! The manual calls for one turn out and I know most suggest starting at 1 1/2 turns out. So now it is starting to sound like this whole time the motor has been running very lean. Could explain the sneezing during idle and especially when throttling up.

 

[jerryjerry05]

Yup sneeze at idle is a lean condition.
Turn them out

 

[trooper1822]

Ok so been working all day on the boat. Got the carbs put back together and so rebuilt the fuel pump. Put a inline filter between the pump and the carbs. Set the mixture screws at 1 1/2 out. Started it up and it idles ok but when giving it throttle it bogged down bad. Kept adjusting the screw in and let it idle a few min between turns. No change in idle until I had the screw about half in from seated. Backed them back out until it started to bog down again. Finally settled in between one full turn out and half a turn. Is this safe? The book says one turn out from seated. But anything more than where I have it it will start to bog down. Used my thermal heat gun around the motor and at idle pointed at the plugs it was reading 110 degrees cyl 1, 111 cyl 2, 116 cyl 3. Motor stays cool enough to hold my hand on it without discomfort. Even high idle it gets to about 125. It is puking water great.

 

[jerryjerry05]

Starting fluid.
Start motor get warm.
Then spray starting fluid around the base of the carbs and the port covers under the fuel pump and the 2 cyl. above and below the pump.
If the spraying causes and slowdown or changes the idle at all???
Then your sucking air and need to figure out where??

There is a long dog bone shaped cover on the stbd.side .
It is the cyl.drain cover.
Pull it and check to see if it's clogged?
It should have a tiny screen.
It gets clogged and can cause poor idle and make it starve for air.

Is the plenum still on the front of the carbs?
Make sure the hose on the bottom is hooked to the cover and the nipple on the base of the block.

 

[trooper1822]

Looked over everything today and checked all hoses and replaced a few that looked work out. Pulled the cyl Drain cover and it was clean. Ran with the plenum cover on and reset the carbs again to one turn out. Still ran rich. Sprayed starting fluid around everything and got no changes in idle speed. Backed them in just a tiny amount and was able to get it to rev up but can still tell it is running rich. Good amount of oil pooling in the water on my driveway. Temps are still staying low and the block does not get very hot and the water coming out is not too hot, more luke warm. Let it run for 15 min today and exhaust is pushing out lots of smoke. Thinking at this point I'm going to have to take it to the lake and see how it runs and make further adjustments with it in the water vs on the muffs.

 

[jerryjerry05]

Yup in the water should make a difference.
The adjustments need to be done in the water and in gear.

Running at idle and lower speeds makes them smoke a bunch more.

You pull the thermostat?
88/85 hp. should be a 110d so it probably won't be too hot.

No thermo can make it run rough too???

 

[trooper1822]

If I were to get a drum and lower the lower unit into it could I make the adjustments off of that with the unit in gear or do I need to actually be on the water? I do have a big tub that I can use if that will work. Probably won't make it to the lake for al least another 2 weeks. Have not pulled the t-stat yet. That will be sometime this week.

 

[trooper1822]

Here is a video of it running
https://youtu.be/v-H31gh4afQ