Changing aFuel filter

[bazza]

I have a spin on fuel filter attached to the transom that requires changing.

Is it best to turn off the fuel and run the engine until it stops then change the filter or just "go for it" and replace it when it's full of fuel?

[Jizm]

not sure but there shouldn't be any flow with the engine off...

[Mollers]

Is this a trick question?

Unscrew-remove old. Screw on new, give tit a sqeaze.

I tend to pour the contents of the old filter into a jam jar to see what it's collected. If it looks OK, I pour the 20p worth of petrol in the mower.

[jyasaki]

Originally Posted by bazza

Is it best to turn off the fuel and run the engine until it stops then change the filter or just "go for it" and replace it when it's full of fuel?

Won't make a difference. As the fuel is used from the filter, it's replaced by sucking fuel up from the tank.

Place a bunch of towels underneath, and have a bowl or something handy to empty the old cannister into once you get it off.

Remember to reprime the filter using the bulb before starting (filling the cannister with fresh gas before installation helps but can be messy.)

jky

[bazza]

Thanks jky,

I have a tap just as the fuel line leaves the tank and I thought if I turned that off then ran the engine the fuel in the line and filter would get used then it wouldn't be so messy. However I wondered if running the system dry would cause any problems when I try and restart the engine.

Sounds like I go for the "unscrew, rescrew then squeeze my tit" solution

[Erin]

If you turn the tap off and run the engine then it'll create a vacuum which will prevent the fuel being used. Might even damage the fuel pump. However, it is still worth turning the tap off, replacing filter and then making damn sure you tunr the tap back on again. How do I know this?????

[jyasaki]

Originally Posted by bazza

I have a tap just as the fuel line leaves the tank and I thought if I turned that off then ran the engine the fuel in the line and filter would get used then it wouldn't be so messy. However I wondered if running the system dry would cause any problems when I try and restart the engine.

Carbed, maybe. Though as Erin pointed out, you need to allow air to replace the burned fuel. A lot of injection systems don't like being run dry (though that bit is from the early car/diesel days, and may no longer apply.)

Plus, there's probably a pint and a half of fuel in the filter and line - going to take a looong time to burn that up at idle...

Sounds like I go for the "unscrew, rescrew then squeeze my tit" solution

Yeah; if you had done that to begin with, you'd be done and be inside watching TV with a couple of beers inside you by now.

jky

[bazza]

Okay, fuel filter changed. The missus said the last bit hurt but I told her it was necessary .

My primer bulb is after the filter, Is this normal?

[Nos4r2]

Originally Posted by bazza

Okay, fuel filter changed. The missus said the last bit hurt but I told her it was necessary .

My primer bulb is after the filter, Is this normal?

I prefer this setup. It's how I have mine. It means if you get an air leak on a union, you don't piss fuel out as you pressurise-it just means the bulb feels 'bubbly'.

If it's a seethrough bowl you can see the air bubbles too.

[Mollers]

Originally Posted by bazza

The missus said the last bit hurt but I told her it was necessary .

Maybe she squeazed you a little too hard.

[jyasaki]

Originally Posted by bazza

Okay, fuel filter changed. The missus said the last bit hurt but I told her it was necessary .

My primer bulb is after the filter, Is this normal?

It's the way mine is set up.

Some people worry about "pushing" contamination through the filter, but I don't really see any difference either way.

Actually, now that I think about it, a leaking primer bulb will be leaking cleaner fuel if it's after the filter...

jky