Ok Merc issues

go back thru the fuel system again just to be on the safe side, pull the carbs down and blow them out again, you might have picked up some trash. Make sure you check the float levels(been there, done that), make sure they are not too low. Once you fell the fuel system is ok, take a hard look at the stator, sound like the high speed windings may be going out. I know you and BS swaped out a bunch of the ignition earlier, was that new stuff you ended up with on it? Oh, and don't forget to check the things we all forget about, battery cables, ground connections, harness conections, kill switch, etc.. BS, you got another boat harness you can plug into the motor to eliminate the harness side/kill circut?
 
Sounds like MJ needs to start with step #1 of engine diagnostics. Get you a remote tank and hook it up with 5 gallons of fresh gas and see what happens. This way the shavings and possible fuel restriction can be eliminated. Drain the float bowls and try to catch it so you can see if metal made it that far. The metal in the filter makes me think you have debris in the anti-drain back valve(if you have one) or something in the fuel pick-up tube.
 
Yes I agree. Last fall when I bought the boat the guy told me that the gas tank did not work?
I took the floor up and cleaned all gas out and dryed the tank to be sure I got every thing out and it was clean.
Then I replaced all hoses and doubled clamped them. Whenn replacing the hose to the vent, I found the vent all rotted and not even there anymore, just a hunk of white crap. There was the proble all along.

Since then I added the racor and have had no problem all May,June July. But that is when I added the Mercury (LOL) all parts that BS changed when trouble shoting the motor before were used parts, so there could be issues there as well. He did test things with a meter and checked all numbers with the book to besure they were with in spec's.

Man I wish I could just buy a new motor and be done with this stuff for a while!! Its feast or famon here at my house!! Last winter I was loaded!! Bought all new eletronics, hard top, and a bunch of other stuff. This year I am pooer then dirt!!
 
Well I see nothing from the tank to the motor??? I was good, But I will have to wait for help to go any further.

I never did look at that new filter before installing it, I have had on more then one occasion bought auto parts that had shavings from being made in them, I wonder if thats the case with the filter housing?

I don't think is anything from the tank to the motor. But fuel pump on I have no idea?
We did rebuild the fuel pump with a kit, the only thing that we did not change was the ck vaules?
We had all the carbs off, cleaned, and BS checked all the setting I assume? and we put all new gaskets.

well I think I am going for another Tuna if the weather holds out on wed.? Sputter or no sputter!!
 
O yea. gas tank Galv, and shavings did not stick so must have been stainless or Alum? from were is anyone's guess?
 
MJ, not to derail on the fuel issue, do you have steam coming out of the pee hole or water with steam rising off it? i re read some earlier post and noticed you stated steam. are you hi temp sensors working?
 
Can someone pass me a gun PLEASE!!!!!!!!!!

Long story short I have no gauge hooked up. :cen: Does anyone know the right wire for the temp?? BS said Tan or Tan with Blue strip?? he wasn't sure??
 
alarm circut is tan with a blue stripe, just ground the tan/blue wire with the key on and it should sound the alarm. Tan wire is for the guage. If you have the time, replace the alarm sensor in the head, make sure you clean out the hole it came out of, you never know just how old that sensor is. You can check the sensor with an ohm meter and a pot of hot water on the stove, just hook the ohm meter leads to each wire, put the meter on Ohm or diode check, drop it int hte water making sure the wires don't touch or come in contact with anything that will conduct, turn the stove on adn wait for the connection to be mae, check the temp with a thermometer
 
Thanks Spare, I don't think there is even a alarm horn installed in the boat? That is the day BS had to bring me to the hosiptal and he put the controlls and stuff in all by himself.
He was in NH this week end so I try to get him on the phone tomorrow.
 
Ok I looked up the SS# and it seems that my motor is a 1985, not 1987 like I thought it was, just incase this makes a difference.
 
find the alarm under the dash, it should have a purple wire(key on power) hooked to one side, make sure it has 12 v when you turn the key on, then it should have a tan/blue wire hooked to the other lead, when grounded out, this wire comepletes the circut, sounding the alarm. You can make one using any kind of 12 volt, l,ow amperage, horn or buzzer, seen people use seat belt buzzers before, just make sure its loud enough for you to hear it while underway, and always check the circut by grounding out the wire back at the sensor, with the key on, to check the alarm. If you feel real adventurious, you can hook a red light to the alarm as well and mount it in the dash to give you a visual warning as well, just wire it in parallel with the alarm
 
Like I told you over the phone. Stop fixating on the temp problem! Worry about that later. The sputtering of the motor is not related to the motor running hot at low RPMs. The sputtering, bogging, cutting out (whatever you want to call it) only happened at higher RPMs when the motor is running at it's coolest. The problem never materialized at trolling speeds. You either have a fuel problem with the pump or something in the the carbs like a blocked jet. If not, then it's electrical.
For all your worrying about the higher temps at trolling speed, that motor ran at trolling speed for close to five hours and never once missed a beat. Worry about the other problem first. One thing at a time.
 
Trying to get a few more details here MJ.

When the problem occurs it is at high RPM's correct?
What happens if you come off plane and run it for a few minutes and then get back on plane?
Does the problem immediately return or does it take a few minutes again? What happens if you go WOT?
How many RPM's is it actually dropping when this happens?

The more I think about your problem, the more it sounds like a restriction going into the float bowl in front of the needle and seat. This would cause it to run good for a minute or 2 until the fuel level in that bowl drops below a certain level. Then it would go to missing. If when you come off plane for a few minutes it comes up and run's normal again I would check for a blockage in one of the carb inlets, or possibly a blockage in front of one of the main jets. To check for a blockage going into the carbs. Drain the bowls out and leave the drain plugs out. Get somebody to pump the primer bulb and look for fuel to come out. You want to look for the drain that doesn't have much fuel coming out of it. If they all drain out the same amount then it could still be a blockage in front of the main jet.

I've seen this happen before on a few occasions where you have a fairly large piece of debris floating around in the carb bowl. It takes sometimes 30 seconds, sometimes 5 minutes for the debris to cover the main jet over. A blockage in the needle and seat entrance will normally take the same amount of time every time for the problem to occur.
 
CB :shut:


Ok BS came by today and just left. We found that one ck vale in the fuel pump was sticking so we changed it out, seems fine now.
There was no metal shavings of any kind on the pump screen so i guess they never got by the Racor.

We had a hose getting kinked some when the linkage was at wot and we fixed that also. We drained the bowls but did not do the test you said as I did not read this before hand.

Plugs are pretty dirty and replaced. The motor starts like a dream and idles fine!! BS felt the water and said I am good to go! I still hate how hot it is but everyone says its good then it must be!

When we had the carbs off before we cleaned the crap out of them and set the floats, and reinstalled, and since tere was nothing on the pump screen I am sure they are still that way, At least I hope so??

We really don't think its a fuel issue at this point?? But I have not put the boat in the water yet to see if anything we did today helps??
I will try to get out tomorrow to test it and see, I will also try your test to see if it is something there. When I came down to plane before it would clear up and when I gave it gas it would started immediately again.
But waited to start for a mile or so when it would first show up.

I am hoping it was something we fixed today?
 
O yea only happens at high rpms, 4000 and above. when it happens I lose 1 to 500 rpms, mostly it starts losing 100 and goes to 500 as you go. I just give more gas to get them back up but still sputtering.

see what happens tomorrow? Thank
 
Does it eventually smooth out and sound like it has lost a cylinder? This sounds an awful lot like a fuel issue where your losing one cylinder. Although it could easily be a switchbox or stator issue. When it does it next time shut it down while it's doing it and go back and pull all of the plugs out. Look for the one that looks like it's not firing or out of the ordinary. If they all look uniform, but the problem is still there I would suspect the stator's high speed side. If one of your plugs looks really light in color then you know which carb to check. If one plug looks wet or fouled then check the ignion for that circuit. You need to isolate the problem so you know which are to address.
 
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