Fuel Filter or Bad Fuel

WahooUSMA

WahooUSMA

Member
Jan 5, 2012
124
Southern California
Boat Info
2002 290 Amberjack
Engines
Twin 5.0 Merc Bravo III
Where is the fuel filter on 2000 270 Sundancer 7.4 merc?

It was a nice weekend here in So. Cal so I took advantage of the weather and headed over to Catalina for lunch. Prior to leaving, filled the boat with 89 octane shell gasoline and topped off the water system. On the way over the boat ran very well - I did notice planning was difficult and had to use a ton of trim to get the boat on plane, but I attributed that to 5 adults, fuel and water (used less than a 1/4 tank of fuel going over). Topped the tank again before we left Catalina with 15 gal, for good measures.

As we left Catalina to return to our home harbor, I could not even get the motor to rev to 3 grand. I told my wife the boat feels like we are dragging a lobster net, in fact I actually lifted the drive to verify, twice. I throttled back to neutral and hit it again and this time the engine came to life and we were moving. In hindsight, should have returned to Catalina and played it safe. About 5 miles into our crossing, the RPMs fell and my speed dropped to 10 mph. Did the throttling back/throttles forward a few times and we were good to go. The engine seemed to run rough as we accelerated, and actually backfired a couple times. This scenario happened about 5 times during our crossing back.

I believe my fuel filter might be clogged or crappy gas. Oh yeah, I burned over 1/2 coming back (approx 29 miles). I was also thinking fouled plugs or plug wires.

So my question is, where the heck is the fuel filter located on my 7.4, 2000 270 Sundancer:smt100? And do I have a fuel/water separator?

I have read on this great site and have been told to carry a spare filter....Since I carry one, it would probably be a good idea to learn how to change it and where it is located???

Thanks for a great site!

GO ARMY BEAT NAVY!
 
As for the filters location, you can follow your fuel lines to the front, lower starboard corner of the engine. Being a 2000 model, Im guessing you are fuel injected, not carbed. Take your serial # to the Mercruiser site. There you'll be able to find specific information for your engine.
 
Installed new fuel filter and plugs....turned over and ran for 15 sec then just shut down.....Turns over but does not fire. It seems like starving out!
 
Did you fill the filters with gas? keep turning the ignition on and off to get the fuel pumps to fill the filters and it will eventually get gas to the motors

Sent from my VTAB1008 using Tapatalk
 
A little out of my league but I dont think it is as simple as getting the pumps to fill the filter. Remember, the OP had this problem while underway before replacing the filter. Hopefully some of the more experienced guys will chime in with words of wisdom about fuel rail presures and the like.

The OP did not mention any alarms which I think low fuel presure would set off. He did however put fuel in it before departure. How often "bad gas" actually happens I don't know. But we cant rule that out yet either. Again, this is all a little out of my league.
 
I couldn't wait until tomorrow. Removed the filter, filled with fuel and it fired right up. Turned it on/off numerous times and it runs just fine.......thanks'
 
WahooUSMA said:
I couldn't wait until tomorrow. Removed the filter, filled with fuel and it fired right up. Turned it on/off numerous times and it runs just fine.......thanks'
Click to expand...
That's strange, I had the same motor in my Baja yrs. ago, 7.4MPI 310 HP, and I never had to prime the filter (there again, it would stall a couple of times and then she was good to go) Glad your up and running!!
 
WahooUSMA said:
I couldn't wait until tomorrow. Removed the filter, filled with fuel and it fired right up. Turned it on/off numerous times and it runs just fine.......thanks'
Click to expand...

Question is, how long did you run it?

The engine could be running on the fuel that you filled the filter with. If your fuel pump will not prime the filter itself, the pump could be weak. "I" would put a pressure guage on the output of the pump and verify pressure is there, to make sure it's not weak. I don't know what your pressure should be running but you can look that up on the internet. My feeling is like Lances, it should prime itself, albeit the motor stalls a couple of times.
 
These systems do not have a return line and therefore can and will air lock. When I was chasing my hot start problems that the whole world was calling vapor lock (which it is not) I put clear tubing so I could see if it was drawing air. I put new filters on. She started and ran but there was no gas in my tube and she died. I pulled the filters, filled them and put them back on and she ran flawlessly with zero air bubbles. Now you have to know, I have the additional electric pumps because the previous owner had everybody checking the hot start as well and everyone was convinced she was vapor locking. So I know I don't have pump problems. These systems can and will air lock. I still have somewhat of a hot start problem that I will be working on this summer with Mercruiser techs. Everyone can save time and hassle simply by filling the filters and be done with it...IMHO
 
floriduramax1 said:
These systems do not have a return line and therefore can and will air lock. When I was chasing my hot start problems that the whole world was calling vapor lock (which it is not) I put clear tubing so I could see if it was drawing air. I put new filters on. She started and ran but there was no gas in my tube and she died. I pulled the filters, filled them and put them back on and she ran flawlessly with zero air bubbles. Now you have to know, I have the additional electric pumps because the previous owner had everybody checking the hot start as well and everyone was convinced she was vapor locking. So I know I don't have pump problems. These systems can and will air lock. I still have somewhat of a hot start problem that I will be working on this summer with Mercruiser techs. Everyone can save time and hassle simply by filling the filters and be done with it...IMHO
Click to expand...
I'm not disagreeing with you at all Donnie, I'm just saying I've NEVER had that problem with any of the 6 searays I've owned (all mercruisers) and one Baja, one of them MPI, and 3 EFI's. But maybe I will tomorrow...LOL
 
islandhopper00 said:
Question is, how long did you run it?
Click to expand...


I ran it for a solid 10 minutes last night. I am going to run it again tonight for good measures.

This scenario seems very similar to my tow veh, 2004 Chev Duramax when I had Jiffy Lube change the fuel filter. They thought the pump would self prime after changing the filter.....big time wrong! You have to have fuel in the filter or you will drain the batteries trying to get the pump to prime....It's a pain in the @ss trying to jump start a diesel!

Thanks!
 
WahooUSMA said:
I ran it for a solid 10 minutes last night. I am going to run it again tonight for good measures.

This scenario seems very similar to my tow veh, 2004 Chev Duramax when I had Jiffy Lube change the fuel filter. They thought the pump would self prime after changing the filter.....big time wrong! You have to have fuel in the filter or you will drain the batteries trying to get the pump to prime....It's a pain in the @ss trying to jump start a diesel!

Thanks!
Click to expand...

I ran out of deisel once and it is a pain. I have a manual pump under the hood that I pumped for like 20 minutes before it started.
 
You must log in or register to reply here.

Forum statistics

Threads
113,182
Messages
1,428,073
Members
61,089
Latest member
KDKING
Back
Top