Replaced filter, engine no longer revs high. Why?

[Cheechako]

Originally Posted by antoha

from what i can tell - no added smell or dripping. and the bowl stays full.
Remove the lid carefully and make sure the filter is staying full.
speaking of goop: what to use? permatex 2? and do i need it on the fittings that go into the racor housing?
NO, the orings are fine.
the fittings on the hoses are those pivoting compression fittings - when it's not tight enough, the leak but not from the attachment point but somehow behind the articulation; when tightened, that stops. the hoses are 5/16", while the fittings are 1/4".

Pivoting? Not sure that is good.
See bold comments in the quote.
Don't worry about fittings, bends etc, the 500 racor is overkill for your engine. Plenty of flow.

[antoha]

sorry, by pivoting i meant swivel fittings. if a fitting is attached to a hose rigidly, how would you tighten the nut on it? you'd need to first "undo" the twisting and turn the hose as many turns in the opposite direction before you can start tightening the nut. my fuel lines don't have hose clamps on, fittings are already attached to the fuel lines and i am not messing with these. the photos i have earlier in the thread show the swivel fittings on the fuel lines.

[Crabby1]

Originally Posted by antoha

from what i can tell - no added smell or dripping. and the bowl stays full.

speaking of goop: what to use? permatex 2? and do i need it on the fittings that go into the racor housing?

the fittings on the hoses are those pivoting compression fittings - when it's not tight enough, the leak but not from the attachment point but somehow behind the articulation; when tightened, that stops. the hoses are 5/16", while the fittings are 1/4".

I meant to unscrew the top off the razor and see if fuel is still above filter. Also make sure the o rings are seated properly with no junk in groove and are not pinched. Usually if its an air leak the rpms will NOT be constant.

Permatex is good, I don't remember which number but get the one that doesn't harden.

Again, I would take 5 minutes put a small tank above engine, run fuel line to engine, if your rpms are back up to 2500 you need to find air leak. If your rpms are still at 2000 it is going to be fouled prop and/or growth on hull. IMO

[Cheechako]

Originally Posted by Crabby1

I meant to unscrew the top off the razor and see if fuel is still above filter. Also make sure the o rings are seated properly with no junk in groove and are not pinched. Usually if its an air leak the rpms will NOT be constant.

Permatex is good, I don't remember which number but get the one that doesn't harden.

Again, I would take 5 minutes put a small tank above engine, run fuel line to engine, if your rpms are back up to 2500 you need to find air leak. If your rpms are still at 2000 it is going to be fouled prop and/or growth on hull. IMO

.....Or a clogged tank pickup tube. That is not uncommon.


Re-reading the original post.... I think you need to get a good look inside the tank.
- How old is most the fuel? Get an outboard motor squeeze bulb and hose, take a sample off the bottom of the tank, put it in a glass jar and let it settle out. What do you see?

"i just replaced my old racor 200 with a racor 500. the engine is a westerbeke 35c-three, with under 300 hrs on it. have been having fueldelivery problems with it ever since we got the boat (burnt out 3 lift pumps), tank is deep in the bilge so i have close to 5-6 feet of lift from bottom of tank to lift pump. so i decided to change to a filter which restricts flow less."

Don't get confused with other issues like stuffing box etc. It's highly likely You have a fuel delivery problem.
Do as mentioned with a day tank... it can be only a half gallon if that's easy. A milk jug with a fitting on it.
Early on was posted about the merits of an electric fuel pump also.
If you've gone thru 3 lift pumps my money is on clogged pickup tube or real bad fuel.

[Crabby1]

"....Or a clogged tank pickup tube. That is not uncommon."

Very possible, did say burned up a few pumps! Check to see how much fuel the lift pump is pumping if you haven't. That would explain the constant rpm with a mostly clogged pickup tube.

[Crabby1]

"If you've gone thru 3 lift pumps my money is on clogged pickup tube or real bad fuel"

My money is on almost fully clogged pickup tube. (bad fuel sludge would show up in racor)

close 2nd is fouled prop (has not had the rpms up to 2500 this year.

close 3rd is air leak even though it seems it would be the first choice because of just changing filter and possibly introducing air leaks in the system, they always seem to surge with air in fuel.

Who's taking the bets?

[antoha]

if the pickup line is clogged, how would you clean it? just blow through it?

the tank is in the deep bilge. i believe the tank itself is 30" deep, and the only access hole i have readily available is a 1.5" opening on top (with a dipstick welded to the cap). there is a cleaning port also but that's hard to get to (i need to remove the battery compartment etc first) and i'd have to make a new gasket to put it back on. in other words, the pickup tube is a bit hard to get to when you're out "in the field".

i have a pump i bought to make a fuel polishing system (not a project for this season - now i'd like to get out on the water and sail, not set up shop on the boat again) which i could try to rig to the new racor on the output port (instead of the fuel going to the engine). how would i measure if the pump is working too hard / there's clogging in the fuel delivery system upstream of the filter? just use the vacuum gauge? temporarily i could always put it in the t-handle.

[DeepFrz]

If you want to get going and not fix the problem try setting up a temporary fuel tank using a 5 gal. Jerry can and run the pickup line to the input of your new filter.

[Crabby1]

Originally Posted by antoha

if the pickup line is clogged, how would you clean it? just blow through it?

the tank is in the deep bilge. i believe the tank itself is 30" deep, and the only access hole i have readily available is a 1.5" opening on top (with a dipstick welded to the cap). there is a cleaning port also but that's hard to get to (i need to remove the battery compartment etc first) and i'd have to make a new gasket to put it back on. in other words, the pickup tube is a bit hard to get to when you're out "in the field".

i have a pump i bought to make a fuel polishing system (not a project for this season - now i'd like to get out on the water and sail, not set up shop on the boat again) which i could try to rig to the new racor on the output port (instead of the fuel going to the engine). how would i measure if the pump is working too hard / there's clogging in the fuel delivery system upstream of the filter? just use the vacuum gauge? temporarily i could always put it in the t-handle.

Just do it! As my toddler son and NIKE trademark would say.

Blow thru pickup tube, might tell if clogged but won't clean it. Put day tank on it, see if it raises rpm. If rpm's go up to 2500 you know to check pickup tube and air leaks. How was output on lift pumps when installed? If rpm's does not rise time to go swimming and check prop.

If you are just wanting to go day sailing the day tankage will be fine for summer until you get her strait. The longer we put off these little projects the bigger they become.

Good luck i'm out of here

[JPA Cate]

Reading through the preceding posts, I started wondering....1969 boat? possibly the fuel tank has NEVER been cleaned....history of trashed pumps? Sounds like it must be really hard work to suck fuel out of that tank...

So, like Deep Frz said, use a day tank, and go sailing, or fix it now and have it be okay for as long as you own the boat.

You may also have foul prop, no reason you can't have more than one problem at a time, so you could also have a wee air leak, but given the history, I'd suspect the filler clogged, or semi-clogged. It probably worked okay when new. Old, gucky fuel can create "arteriosclerosis" in fuel lines.

Ann

[antoha]

Ann,

fuel tank was cleaned after we burned out the first lift pump (a couple years ago): all old fuel removed, power washed inside, new fuel added.

the filter element is brand new, it is a new filter housing after all.

i don't know if the lines were replaced when the engine was put in (brand new) in 2008 - it would be reasonable to assume they were.

the tank is monel, the insides look good, and i never had to replace the filters more frequently than once a year. the only reason i changed from racor-200 to the bigger racor-500 was the hope that the latter provides less of a restriction which would help alleviate the problem or having the tank too low in relation to the engine.

thank you everyone! so the theories are what Crabby summarized (air getting in, fouled prop, and clogged fuel lines) plus a few others (dirty air filter and stuffing box too tight). i will share the results after i go to the boat this weekend.

anton

[tinkrman69]

you say you put street diesel in? how long ago? street fuel will grow algea. hence clogging the fuel system and filter. also did you put the spacer in when changing the filter element? if not the fuel is bypassing the element and probably clogging the system further down. restricted fuel flow won't stop the engine from starting normally or running to speed at neutral. but it takes a lot more fuel to get to rpm with a load. hence low rpm at load. the upgraded fuel filter needs a spacer ...supplied...under the element, to raise it up high enough to cover the outlet hole in the center pipe. If the above is correct you'll need to change all filters clean the tank and all fuel lines. then blead the system you can try to just chang the filters and correct the primary filter and empty and refill the tank, first. be prepared to change filters often for a while.

[Stu Jackson]

Originally Posted by DeepFrz

If you want to get going and not fix the problem try setting up a temporary fuel tank using a 5 gal. Jerry can and run the pickup line to the input of your new filter.

A good friend had these problems this past weekend. He did the all new hoses, new filters, checked for inlet screen...ALL the stuff.

I told him to do this.

It worked.

He'll pull and clean his tank or replace it.

Just reality.

Cancel that! I just read anton's #41.

Good luck.

[antoha]

tinkrman:

i don't think i need a spacer - that's for using new filter elements with old style housings i believe (and i have a new, new style housing - the ones where the mounting bracket is not integral with the housing itself, i think it shows it in my photos). am i wrong about this?

street fuel: i have about 20 gallons of last year's red diesel mixed with about 10 gallons of street (yellow/greenish) diesel as of a couple weeks ago (the mixture didn't winter, i just added the new stuff). i also added stabil or whatever it was that i had on the boat (the diesel additive) at the same time.

everything about the racor 500 is new: the housing, the fittings that came with it, the filter element that came with it, etc. bowl is clean and clear and i don't see any water or gunk in the filter. given the symptoms, the problem is not likely inside the filter - it's either before or around, if it has to do with the fuel delivery system at all. the problems started after i "upgraded" (although i do not have a clean experimental data point; it was my mistake that i didn't first run the engine under load with the old racor before the surgery, so i could really compare apples to apples).

[transmitterdan]

Generally I don't like Teflon tape on fuel fittings. There is a small chance a piece of tape can get loose and flow down stream clogging up something important. There are thread sealant goops designed to be fuel resistant.
Are you sure that the brass fittings used on the Racor were the right thread type? Racor use I think straight threads and not NPT threads as do most other fuel components,
Have you replaced the on-engine fuel filter?