mercruiser 3.0 fuel problem? ?

[rudy1011]

bought a 1991 sea ray 170 with a 3.0 mercruiser engine..the first time I took it out the boat ran fine for about 20 minutes and then just shut off, and would not restart...after I got it home u noticed no belt on the alternator, I don't know what else that belt powered. I also noticed there was no gas being sprayed into the carburetor when I tried starting the boat, but the motor starts when I spray starter fluid into the carb.. which leads me to believe that I have a fuel problem..am I right??

 

[NHGuy]

Welcome!

Might have run down the battery with no alt belt. Recharge the battery right away, they don't live as long if left discharged for longer periods.
And once you have it charged run the bilge blower, then, with water to the drive, try a start. You can't check audibly for an electric pump though, because it wouldn't run unless the starter is turning or the engine has oil pressure.
If it does not start, put a thimble of gas down the carb and start it again (on muffs so the impeller doesn't run dry) to see if fuel will appear.
And replace that belt.

 

[alldodge]

:welcome: to iboats

Agree and will add go get some gas and put it in the tank. Also put the starting fluid away and use just a tad of gas dribbled in the carb prior to turning it over. Make sure to get all the gas can or what ever you use to put it in the carb away from the engine before trying to start.

Be safe

 

[fishrdan]

Agree, check the fuel tank level, fill if needed and charge the battery completely. If it's a single belt, it runs the water pump and alternator. To change the belt, remove the 2 bolts of the front motor mount closest to the alternator, remove spacer, swap belt, then reinstall spaced and tighten bolts. Tie-wrap a spare belt inside the motor mount, so you don't have to take the mount apart again, if the belt breaks again. Also,,, check the pulleys for rust, if they are rusty they will eat the new belt,,, the pulleys would need to be sanded and painted.

You will need to get the engine started (on the muffs) to fill the carb, after that shut off the engine, remove the flame arrestor, have someone pump the throttle and see if 2 steady streams of fuel spray into the carb, if no steady streams you have a bad accelerator pump in the carb or no fuel in the carb. If the carb bowl won't fill by starting the engine, you can manually fill it through the carb's vent with a ketchup/mustard bottle filled with fuel. (Keep the bottle with fuel far away from the engine while starting and protect it from falling over.) I also use the ketchup bottle to give the carb a little squirt before trying to start the engine if the carb is completely dry. If the engine sputters and turns over 20-30 revolutions without fuel getting to the carb, you have a fuel delivery problem; fuel pump, filters, hoses, tank pickup, etc. .

 

[Fun Times]

Hi there, welcome to iboats!

The below link should be your parts catalog for you to look through. Your engine serial number would help confirm that is the correct parts though.

If the fuel pump is original, it should be a mechanical pump?

Sounds like the battery may be still strong enough to start the engine since you're able to add starting fluid to get it to run for a second. Nevertheless a charge should still be done since the belt may have broke off draining some of the battery underway. Did you find some of the old belt in the bilge area?

One thought would be to confirm if you are getting fuel up to the carb or not at cranking speed... If you are then maybe your carburetor needle and seat is stuck closed. If so, as a quick test, Sometimes lightly tapping around the needle and seat area may unstick it just enough to get the engine running again.

Does this boat have a power steering pump? If so, there would be an additional belt. See Crankshaft, Camshaft, Water Pump for your OEM belt number.

http://www.mercruiserparts.com/selectSerailRange.asp?doc_nbr=3.0L++++GM+181+I/L4++1990-1994

Hope you get it running soon, good luck.