HELP!!! PLEASE

C YENSEN · #1 10-24-2005, 10:05 AM

OK GUYS, WELL I AM STILL HAVING PROBLEMS WITH THE MOTOR (1984 470 MERCRUISER)

SHE STARTS FINE, SHE IDLES FINE, AND THEN I TRY TO TAKE HER UP TO SPEED (3900 RPM) AND SHE WILL RUN AT THAT RPM FOR 2 TO 4 MINUTES THEN SHE GIVES OUT. IT SOUNDS LIKE SHE IS STRUGGLING TO GET FUEL. SHE GOES FROM RUNNING GREAT ONE SECOND TO SPITTING AND SPUTTERING AND CHOKING HERSELF OUT. AFTER SHE HAS HER FIT, SHE WILL NOT GO BACK UP OVER 3100 RPM. SATURDAY AFTER SHE HAD HER FIT, I TRIED TO FORCE HER BACK UP TO SPEED AND THERE WAS A PINGING COMING FROM THE CARBURATOR (LIKE THERE WAS SOMETHING LOOSE INSIDE)

I HAVE REPLACED:

SPARK PLUGS
WIRES
POINTS
CONDENSOR
ROTOR
ALL FUEL LINES
FUEL FILTER (TWICE)

FOR THE FEW MINUTES THAT SHE IS RUNNING WELL THE MOTOR SOUNDS VERY STRONG, BUT AFTER SHE HAS HER FIT, SHE RUNS VERY ROUGH (LOT OF SHAKING)

COULD IT BE THE FUEL PUMP?? I CAN REPLACE THAT, BUT IF IT IS A PROBLEM WITH THE CARB, I WILL HAVE TO TAKE IT SOMEWHERE. I REALLY DON'T THINK I KNOW ENOUGH TO TEAR A CARBERATOR APART.

ANY SUGGESTIONS WOULD BE AWESOME.

I AM READY TO PULL MY HAIR OUT ON THIS ONE. STRIPER SEASON IS GOING BY QUICKLY AND IT IS ALMOST TIME TO WINTERIZE HER AND I WANT TO GET THIS PROBLEM FIXED BEFORE THE SPRING

THANKS GUYS

macojoe · #2 10-24-2005, 10:58 AM

well the fuel pump is cheap and easy to replace, you could try that first, then go for the Carb rebuild.

Have you blown out the vent hoses and the vents them selfs??
Some times blowing them out is not anough!! I swear tht some of them bugs you crazy glue to build them nests!!

Get a small cheap car fuel filter and install in the line, the one you can see thur. This way while running you can look at it to see if it is staying full of gas or nnot getting any when you speed up.

pinging?? seems like te gas you are using is carpy?? getting water in the tank??

Try to use a small gas tank on the deck. If it runs with that then you no fuel delivery is messed up spme where. If does the same with remote tank, see thur filter and fresh gas then I would think Carbs.

Good luck!!

C YENSEN · #3 10-24-2005, 11:05 AM

I REPLACED THE VENT HOSE TO THE TANK, SO I KNOW IT IS NOT ANY SUPERGLUING BUGS. I WILL TRY THE TANK ON THE DECK, AND THE INLINE FILTER.

THANKS

macojoe · #4 10-24-2005, 11:08 AM

make sure you put the filter after the fuel pump!! This way you can see if the pump is able to pump and keep it full!

reelapeelin · #5 10-24-2005, 11:38 AM

Can you get a fuel sample when running GOOD and when running BAD?...water will quickly settle to bottom of tank when boat's not moving...as boat's movement mixes water into the gas, it'll cause what you're talking about...can't be sure cause I'm not there, but I'd be taking a hard look for water in the tank...do you have a fuel ''filter'' or a water ''seperator''?...they are different animals w/different functions.... ;)...

Cyensen, what year model is your V20 and where is the vent intake located?...

C YENSEN · #6 10-24-2005, 12:13 PM

IT IS A WATER SEPERATOR. SORRY FOR USING THE WRONG WORD. THE GUY I BOUGHT IT OFF OF ONLY STORED IT WITH 20 GALLONS OF GAS LAST WINTER (60 GALLON TANK) BEFORE I TOOK HER OUT I TOPPED OFF THE TANK AND ADDED A COUPLE BOTTLES OF FUEL DRY.

IF THERE IS WATER IN THE TANK ANY SUGGESTION ON HOW TO GET IT OUT WITHOUT DRAINING THE APPROXIMATE 40 OR 50 GALLONS OF GAS IN THE TANK ???

IT IS A 1984 V20 WITH ORIGINAL 470 MERCRUISER MOTOR.

THE VENT LINE IS LOCATED RIGHT NEXT TO THE FUEL TANK FILL LINE.

C YENSEN · #7 10-24-2005, 12:13 PM

CANT PUT A FILTER AFTER THE PUMP. THE LINE FROM THE PUMP TO THE CARBERATOR IS A STEEL LINE. :(

C YENSEN · #8 10-24-2005, 12:14 PM

HEY I JUST REALIZED I AM NO LONGER A "NEWBIE" THAT PUT A ;D ON MY FACE.

reelapeelin · #9 10-24-2005, 03:23 PM

Cyensen, can you disconnect the fuel supply line after the fuel-pump, then wire power to the pump to run some of your fuel from the tank? Problem w/this is, if water has settled to below pick-up then all you'll get is gas...if you can do this in the water, possibly as hard as you can, ROCK the boat back and forth to mix water/fuel while you pull a sample (you'll probably need a friend here)...run the sample into a clear container...if there's water there it'll sink to the bottom fairly quickly...remember you're dealing w/gasoline and FUMES are more volatile than the gas itself...keep in mind while runnun' that wire to the fuel pump...

Another thought; will a hose or something slide into your tank from the cap?...if it'll go to the BOTTOM, you can siphon a sample from there...if you can get your hands on a marine or automotive 12v fuel pump, use that instead of siphoning...that way, IF you find water, you can pump it right out ...if you try to feed a hose in from the filler cap, make sure it's clean and it'll have to feed thru a 90 degree neck on the tank; keep turning the hose to get past it...

This should have been my1st question; does your water seperator have water in it?...if so, you'll eventually get it out by continually dumping it...and adding fresh gas...

macojoe · #10 10-24-2005, 03:36 PM

It really does sound like bad gas to me.

Getting it out is not hard, its were to put it all as you are taking it out!!!! :o

You may want to look up that Seafoam stuff that willy was talking about. That mght get you all cleaned up?