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View Full Version : Merc 43 1997 carb floods and stalls wonbt start 70 hours



Robert Beatty
07-07-2002, 02:34 PM
" My perfectly running boat went to the mechanic to have the water pump changed on warranty.

When I got it back they said they could not start it, ran the battery down and found (they say), that my oil sending unit had corroded contacts, they thought this was strange but shrugged their sholders and said they cleaned the contacts and started the boat.

I went to the lake today, it started first time, but once she warmed up it coghed and stalled like she was flooded, I was not able to start it for an hour, where she stalled again after I got up to speed (putting more fuel to it did not help, she went down like she was flooded, even did a little dieseling, I was not able to start her again.

I was towed home, I had a full tank of good gas, I my kill switch was not activated. I looked at the oil sender connections, they seemed ok? I asusp[ecting flooding as apposed to connections, but, i am an auto go, boats are new to me.

Any ideas what may be going on here? "

kiralla
07-07-2002, 05:12 PM
" To Robert Beatty
I dont understand what is the meaning of oil sending unit ,but anyway u maybe have a problem with ur carberator orifices specially the idle one ,try to replace the idle orifice and let me know ,and i ll think more about ur problem and if i get anything helping u i ll send it to u soon. "

Robert Beatty
07-07-2002, 05:54 PM
" By oil sending unity I mean to say the oil pressure switch, it is supposedly tied intot he running circuit, no oil pressure and the engine wil not run.

I am thinking that the carb idle orfic can not be the proble in this isnstance as it came on suddenly. "

kiralla
07-07-2002, 06:07 PM
" To Robert Beatty
I want u to tell me first if u have an oil priming pump
and if u wanna be sure about ur pressure switch u can short circuit it ,if u r familiar with this kindof work ,then try to start ur engine and if it starts stop it immediately and replace ur pressure switch.

Regards

Kiralla "

Robert Beatty
07-07-2002, 06:48 PM
" NO, I don't have a priming pump. I do have two wires coming off of the pressure switch, one is purple and its got 12 volts on it, the other is a black/yellow wire. I was thinking about shorting these two wires together but I am worried that I should be introducing a resistance to the circuit first. "

kiralla
07-07-2002, 07:05 PM
To Rober Beatty
u can short it by connecting the two contact points inside it without removing the wires

Robert Beatty
07-07-2002, 07:55 PM
" Mine is a sealed unit, shaped like a cone on the port rear side of the engine low down near the oil pan. "

bilgeguy
07-08-2002, 06:27 PM
" If your oil low-pressure-cut-out is the problem you engine should fire when cranked, but die as soon as or soon after the starter is disengaged. These are usually bypassed during cranking so you can get the thing started.

I assume from you auto experience that you can tell if the carb was reconnected correctly during the maintenance. Is the choke working properly?

Dieseling indicates that there is something in the cylinders to initiate combustion with the ignition turned off. This is likely carbon deposits which seems to match with your flooding diagosis. Have you looked at the spark plugs?

I wouldn't start fooling with jets yet, but you might want to check the float and needle valve. "

Robert Beatty
07-08-2002, 09:22 PM
" I have confirmed that the electric fuel pump is running, I was not certain it was, but it is now, I jumped it with 12v to see if it would turn.
I have also confirmed I have spark, I grounded a wire lead and spark is jumping.
The carb linkage is ok, all free. I can pump the linkedge and the jets flow fuel.
This engine is almost new, I am very suprised and starting to get baffled by this. No-one touched the timming so it should be ok. Maybe the carb is flooding but I should at least get a start of her, something i am now not geting at all.The lockout switch is ok, I even checked it from one end to the other.... "

bilgeguy
07-09-2002, 10:08 AM
" Have you checked the distributer cap (I assume that this is a distributer ignition)? Look for any cracks, or carbon traces inside. Any moisture. Is the seal around the base of the cap in good shape. I had this problem once, the engine would start and idle fine, get me out of the harbor, and then act up when brought up to power. A cloth wiped through the cap would fix until the next trip. The stick on seal at the base of the cap was crumpled. Fixed it by replacing cap and the seal.

Have you purged any water out of the fuel system? Carb is full, have spark, no firing, maybe the stuff in the carb won't burn. Does it smell like gas or does it smell like varnish?

Have you looked at the plugs? Have you tried a little starting fluid, or a tablespoon of good clean fresh gas down the carb and see if it fires?
Have you checked or replaced the fuel filters? "

kiralla
07-10-2002, 06:33 PM
" To Robert Beatty
Hi, i want u to do the next :
1- remove the spark plugs
2-remove the cables from the distributor
3- close gas feeding source
4- cranck the engine with the starter
5- seewhat coming out from spark plugs holes
6- if it is only gas ,keep crancking until the cylinders become empty and reconnect all the plugs and cables and open fuel source
7- start ur engine again, i think it will work
8- if u find some water coming out with gas from the spark plugs holes tell me to solve this problem step by step .

!!!!!!! be careful and protect ur eyes

Thanks

Kiralla "

PUD
07-11-2002, 03:11 PM
"PUD@TOJ.COM ("") JAMAICA CHANGE THE OIL SENDING UNIT AS THIS IS WHAT THEY SAY WAS CORRODED AND CAUSED THE PROBLEM IN THE FIRST PLACE . HOPE I HELPED! PUD."

PUD
07-11-2002, 03:15 PM
"PUD@TOJ.COM ("") JAMAICA CHANGE THE OIL SENDING UNIT AS THIS IS WHAT THEY SAY WAS CORRODED AND CAUSED THE PROBLEM IN THE FIRST PLACE . HOPE I HELPED! PUD."

Robert Beatty
07-13-2002, 12:17 PM
" OK, here is wher I am at, I took it to the dealer.
The mechanic is still baffled, he has replaced the elctronic fule pump, says its an older style.

Re-built the carb

changed the coil

pulled the spark plugs, he said they were all completely burned off and he figured he had it licked. He also said tmy predesessor had put the platinum plugs in whih is a non-no

Goes to start it and up she come, runs it for half an hour, goees to llunch and bang she won't start, when he does get it started and its back to the old problem.

He figures now it may be the electronic control module. "

Robert Beatty
07-16-2002, 01:56 AM
" That was it, it was the electronic control module! go figure! "