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BF40 idling issues, opened it up, discovered this...

So my BF40 would shut when trying to low idle, so I thought maybe the idle screw needed adjustment. I opened her up, put the earmuffs on, and when running I found this:

IMG_6778.jpg

There was a slow drip of fuel coming from around this part. All the hose connections are good and there the hoses have no cracks, holes, anything. It seems to be coming from the side where the gas enters into this gray box from the fuel filter (on the right).

What is this gray box?

I did adjust the idle screw and it helped, but this leaky gas issue is now my primary concern. Ideas?
 
Thats the fuel pump. As far as I know there are no rebuild or gasket kits available. I have a 1997 BF90a that has 2 fuel pumps and one just started a small drip also. I have to buy a new fuel pump or two, not cheap around $75-90 each
 
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Texas, It looks like an easy fix, having never replaced one there may be a trick or two.. some research might be needed . Since my engine has 2005 hours on it I will be replacing the fuel pump "push rods" and O-rings along with the fuel pumps.
 
Chunchy, No screens on mine just an inline filter just before the fuel pumps. I installed a water separator type fuel filter onto the transom between the engine and fuel tank.
 
Step 1 identify your part at www.boats.net

Step 2 purchase part and wait for arrival

Step 3 remove the bolts holding on the fuel pump and disconnect the fuel lines

Step 4 remove the fuel pump

Step 5 install the new fuel pump, apply the bolts and reconnect the fuel lines

Step 6 crack a beer and smile in amazement and go for a ride.

Its pretty easy for you to do yourself ;)
 
Step 1 identify your part at www.boats.net

Step 2 purchase part and wait for arrival

Step 3 remove the bolts holding on the fuel pump and disconnect the fuel lines

Step 4 remove the fuel pump

Step 5 install the new fuel pump, apply the bolts and reconnect the fuel lines

Step 6 crack a beer and smile in amazement and go for a ride.

Its pretty easy for you to do yourself ;)

Thank you sir! ;-)

A perhaps silly follow up question... my motor's serial number is BAYS-3200574. Looking here:

https://www.boats.net/catalog/honda/outboard-by-hp-serial-range/40hp

How do I know which of these it is:

Thanks!
 
Even worse, regardless of which of those I choose above, I don't even see a fuel pump available.

I've looked at all kinds of sites and can't find one (probably due to the age of the motor).

Suggestions?
 
Glad you got some good info and a easy fix..I was not sure if you had to use a special grease on the push rod or special anti seize on the bolts... I would order a new "O" ring along with the pump, it might be time to replace the fuel lines and filter too..As you know boat maintenance never ends.. Looking at the fuel pump in the provided link above, it looks like it plumbed differently? or do you have pull a plug and to add a nipple to the top of pump?
 
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Just an update: I ordered the new fuel pump, installed it with no problem. Reattaching the plumbing in those tight spaces was about the most challenging aspect.

Be sure to get the O-ring when you order parts. It is not included.

If this happens to anyone else, go ahead and do it yourself. It is simple.

I tested it in the yard on the ear muffs and it worked fine. No leaks and my original issue of cutting off at a low idle was resolved.

I took it to the lake yesterday afternoon and it worked there as well.

Of course, a new problem popped up: after 15 mins or so on the muffs, I my overheat alarm went off. I wondered if it just wasn't getting enough water flow via the muffs. But then when I lake tested the fuel pump yesterday, it worked fine idling for 15 mins once I put it in gear at a slow to medium cruise, the alarm came back in about a minute. I had noticed over the last month or two that the pee stream went from strong to medium to weak to nonexistent.

Sigh. I guess I'll create another thread. The impeller and thermostat were changed by the dealer 19 months ago, so that seems pretty soon for anything go out again. But I do fish quite a bit. Don't know what else it could be. Maybe I'll take the plunge and try doing those things myself too with you guys' help.
 
Just an update: I ordered the new fuel pump, installed it with no problem. Reattaching the plumbing in those tight spaces was about the most challenging aspect.

Be sure to get the O-ring when you order parts. It is not included.

If this happens to anyone else, go ahead and do it yourself. It is simple.

I tested it in the yard on the ear muffs and it worked fine. No leaks and my original issue of cutting off at a low idle was resolved.

I took it to the lake yesterday afternoon and it worked there as well.

Of course, a new problem popped up: after 15 mins or so on the muffs, I my overheat alarm went off. I wondered if it just wasn't getting enough water flow via the muffs. But then when I lake tested the fuel pump yesterday, it worked fine idling for 15 mins once I put it in gear at a slow to medium cruise, the alarm came back in about a minute. I had noticed over the last month or two that the pee stream went from strong to medium to weak to nonexistent.

Sigh. I guess I'll create another thread. The impeller and thermostat were changed by the dealer 19 months ago, so that seems pretty soon for anything go out again. But I do fish quite a bit. Don't know what else it could be. Maybe I'll take the plunge and try doing those things myself too with you guys' help.


When running them on muffs, you need to tape (duck tape) off the vent grid above the propeller. I always run in a trash can as it is more realistic to a lake.
 
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