Fuel feed

[edcourter]

Starting on my 86 M260 (v8 4b carb, mech pump) has been getting harder and longer over the last 4 tries. Runs good after. Checked carb squirt and choke first and they looked good. Now, after sitting for a few days and I opened the drain on the fuel filter/sep I get nothing? It will still start eventually.

 

[Grub54891]

Did you check the anti syphon valve at the tank? Could be stuck open, letting fuel to flow back to the tank. The carb should hold it's own fuel, and start normally though.

 

[Scott Danforth]

you could have two problems. the first as Grub pointed out is a stuck (or missing) anti-siphon valve.

the second being the typical Rochester welsh plug leak

both easy fixes

 

[alldodge]

Starting on my 86 M260 (v8 4b carb, mech pump) has been getting harder and longer over the last 4 tries. Runs good after. Checked carb squirt and choke first and they looked good. Now, after sitting for a few days and I opened the drain on the fuel filter/sep I get nothing? It will still start eventually.

Drains on water separator filters are OK for outboards or diesels, they are not good for gas I/O and inboards

 

[Bondo]

Ayuh,...... That's,^^^, My 1st thought,....

My ole tinbarge, the fuel feed is uphill, whether sittin' in the water, or on the wagon,....
Can't drain, Uphill,....

 

[edcourter]

Thanks, The anti S. valve looks like an easy $10 replace. The cartridge filter with the drain is between the tank and the pump, there is also a cartridge filter w/o a drain between the pump and the carb, looks OEM. To eliminate the bad idea drain I have two choices, Try to find a non drain cartridge filter for the first unit or remove the first unit and replace the OEM filter very often? The drain type cartridge is a NAPA Gold 3418, Will another cartridge (no drain) replace this. Is a $320 rebuilt carb (called remanufactured but does include shaft bushings E Bay) a good way to go on the carb (original might be 30 years old)

 

[alldodge]

The napa 3418 (wix 33418) is a diesel filter. The good thing is its an all metal can filter, the bad is the micro rating (12) is for diesel so gas passes larger particles. Your motor did not come with an inline filter between pump and carb.

http://www.mercruiserparts.com/bam/s.../31733/1077/80

The Merc filter for your motor is 35-802893Q01 which also Wix 33226, napa 3226.

NOTE: the filter head which is on the motor is not original. The thread from current 3418 is 1-12, the Wix 33226 is 11/16-16. Someone replaced the filter head with one off a diesel truck.

The filer head part number is 89876A3. Found a few at iboats, and here is one of them
https://www.iboats.com/shop/boat-mo...er-separator-universal-kit-smart-boating.html

Only thing about the one above is it does not state the standard filter can be used. It probably does but find nothing which says it does. Here is the listing for all others (3 pages)
https://www.iboats.com/shop/boat-motor-parts/fuel-systems/marine-fuel-filters.html

 

[edcourter]

The two filters are in series upstream of the fuel pump, my mistake. The first one is the 3418, which I will remove (less is better) the second one (this one appears to be OEM) has a Fram PS 3808. Some cross references show this as a substitute for the Quicksilver 35-802893Q01, some do not? Is this a substitute, and given that It will now be my sole fuel filter, is this the best substitute. There was some discussion about long and short versions on the forums?

 

[alldodge]

The fuel filter should be before the pump, this protects the pump and carb. All you need is one filter and the Fram or OEM would be good. Most here don't get Fram because of low quality control.

Since the filters where up stream after the pump, and your filter had no fuel, then you may have a bad pump. You can check the fuel pressure which should be 3-7 psi.

 

[edcourter]

Both filters were between the pump and the tank, flow wise, upstream being the tank and downstream being the carb. Thanks for the help.