Black anchor fuel issue - stalling in gear at low revs
Evening folks.
My 2001 25hp merc is having some issues with running. Once it's up and going all good and it's happy to zoom around all day, but getting there is the issue.
backstory:
hasn't run for 12 months and then nearly 12 months before then.
Got it serviced 15th Jan prior to a trip south. Carby was cooked but recovered. Fuel tank had been empty and I made up new fuel for it before service.
took it for a run before we went south and it started fine, ran fine for the first 10 minutes then as we slowed down to drop some crab nets, it wouldn't accelerate again and stalled. Started again, stalled again as it went into gear. Repay again.
finally got it going after massaging it through the stall point and it worked fine other than loosing reverse....
down south, it took a bit to get going and stalled a lot at low revs. But once it gets going it's fine.
Three trips out down south with the same. Once it's in gear it stalls, but once you get it past that point, it zooms around no issue.
today, reverse has disappeared again. Stalled as I putted away from the ramp but got going again to garden island where it started playing up hard. Turned out to be the fuel hose which I replaced. See other thread for the story on that one.
anyhow, on the way home, it continued to stall once in gear but I discovered that the fuel bulb is going soft at the point in which it stalls but if I vigorously pump the bulb, I can get it past that point without any dip in revs.
we got back from GI at 15-20 knots and stalled as I approached the jetty and went to accelerate from idle.
the motor is one of those ones that you cannot rev unless it's in gear without lifting the cowling. When I do that, it backfires and stalls.
Out of the water, when in gear, it doesn't stall. I can take it right through the rev range without issue (sorry neighbours).
So fuel hose is new and bulb stays hard
fuel is new
spark plugs are new
connections to fuel tank and motor seem tight
carby copped $150 of service 20 days ago. $850 in total! More than my 250hp!
any ideas?
Jim
Posts: 1342
Date Joined: 05/05/06
Far from an expert but Id be
Far from an expert but Id be checking out the carby? Are you losing reverse because it's stalling?
Edit; going by the other post, sounds like the fuel lines or tank giving you grief? Sucking air maybe?
Bend over
Swompa
Posts: 3916
Date Joined: 14/10/12
Cannot seem to understand
Cannot seem to understand the loss of reverse. It doesnt matter if the motor is running or not, sometimes i just cannot turn the throttle into reverse. Painful when coming into a jetty or mooring but the lesser of the issues so i just come in slow (sometimes because i have stalled
)
Picked up a brand new fuel tank and cleared all the red swarf out from inside it. Syphoned the top 2/3 of the tank into the new one. Re-terminated all the fuel hoses on the new line and gave it a backyard run yesterday...but it never has issues in the backyard.
I drained the old tank and pulled it apart. There was a little bit of crap in the bottom of it. The filter is fine and nothing seems to be blocking it.
The old tank has been drained now and is squeaky clean
Fuel tank and hoses have been eliminated as an issue now but i wont know until it gets a run under load.
Faulkner Family
Posts: 18092
Date Joined: 11/03/08
Sounds a bit stupid but have
Sounds a bit stupid but have you checked the breather hole in the tank. I have had similar issue years back and found the breather in the tank was getting blocked up a bit
RUSS and SANDY. A family that fishes together stays together
Swompa
Posts: 3916
Date Joined: 14/10/12
Sound query and the first
Sound query and the first thing i checked. The screw vent seems to be in ok condition and has now been degreased to eliminate any chance of a blockage.
Fuel does come out of it when I overfill (which gives it a good flush)
Bodgy 79
Posts: 298
Date Joined: 04/08/22
Idle
The idle speed could be a little low or the idle passage in the carby blocked are a couple of likely causes
scubafish
Posts: 964
Date Joined: 15/08/12
try
https://www.boats.net/search?q=%3A2001+25hp+merc
Try can of carby clean through it when running.
http://img.gg/BQ91Sys
Jim
Posts: 1342
Date Joined: 05/05/06
I had a mariner that had
I had a mariner that had trouble shifting, it was the tiller type that you twisted the handle to get into fwd or reverse, the mechanism that held the shift rod in place broke
Bend over
Swompa
Posts: 3916
Date Joined: 14/10/12
So I degreased the pants off
So I degreased the pants off the motor. I would suggest it has never been so clean. I also tinkered with the idle screw and managed to find a groove where it isn't stalling any more.
The gear issue remains but I will work on that at some point.