5.7 TKS fuel filter

My 5.7 carb'ed Merc gave me some trouble the last time I was out on the water. At low speeds, the RPMs were "wandering" up and down a bit. The engine was running rough and actually stalled out on the way up to a fuel dock. Filled the boat up (only need about 10 gallons in a 50 gallon tank) and ran for another 1-1.5 hours. On the way back to the dock (again at low speed) the boat started to act up again and stalled out. Was able to get it restarted, but it wasn't easy (lots of cranking). Got it to the dock and put it up on the lift to deal with later.

Sounds like water in the fuel to me; so I was going to put on a 3rd party Racor with a bowl on the fuel line. However, after looking some more, it appears that my engine already has a filter mounted on it. This filter was changed about 6-7 months ago (during it's annual service). It appears to be a 802893Q01 filter that's on the engine right now.

So, couple of questions. Will I hurt anything by putting a Racor inline with the filter that's already on there? I live in FL; it's always wet here, and, of course, I'm getting E10 gas, so I figure more water removal is better than less.

Does this sound like classic "water in the gas" symptoms? I always keep the boat pretty full, but I don't burn that much gas (maybe 5-15 gallons a trip), so I'm wondering if the fuel has just been absorbing water and now there's too much.

Should the filter I have be able to deal with this situation? Instead of the Racor, should I just buy a replacement filter (which I'm going to do either way) and see if that resolves the situation? I'm wondering if the filter I have is "full" and unable to pull out any more water?

And, finally, is there anything else that stands out (IE, you need to check "this" because I had a very similar problem on my boat)?

Thank you!

Mike

Re: 5.7 TKS fuel filter

Should the filter I have be able to deal with this situation? Instead of the Racor, should I just buy a replacement filter (which I'm going to do either way) and see if that resolves the situation? I'm wondering if the filter I have is "full" and unable to pull out any more water?

And, finally, is there anything else that stands out (IE, you need to check "this" because I had a very similar problem on my boat)?

Click to expand...

Ayuh,... The filter there now is completely capable of doin' the job...

If yer gettin' Alota water, change it more often...
When ya do, dump the contents into a jar, so ya can See the water, or crud...
Those filters can be had from Napa, either the 3225, or 3226, same filter, just 1s abit taller...

The only thing jumpin' out at me is, I'm thinkin' the water has already migrated into the Carb....
A clogged filter usually shows itself at or near Wot...
Clogged passages in the idle circuit in the carb, will cause yer low speed issues...

Re: 5.7 TKS fuel filter

So you think I need a carb rebuild to go with the new filter?

I'm going to go out this weekend, dump the filter that's on there and put a new one on. Hopefully the water was a result of the boat sitting for so long before I bought it and I won't need to change them all that often.

I like the idea of the Racor because you can just dump the water out of the petcock at the bottom; sounds like I should just stick with what I've got and trash the filters when the fill up instead though?

Thanks for the help!

Mike

Re: 5.7 TKS fuel filter

Just wanted to update this thread with my results..

Replaced the spin on type fuel filter (which is fuel/water seperating). Kind of PITA to get to on my boat, but, after about 5 mins of struggling, got it off. Poured the contents into a bin; can't really say what was in there though. Looked like mostly fuel, but had some "cloudiness" to it. When I held it up to the sun, it looked like there were "swirls" of something through the fuel. Not sure if that's normal or not, just relaying what I saw.

Anyway, put the new filter on, and, after some cranking, boat fired right up. Let it idle for about 20 mins at the dock, seems to have resolved the "hunting RPMs" issue that I was having before. Shut it down and it started right back up (this was also sometimes problematic, it would start, but could require some cranking).

Appears to have resolved the issue. The filter on there was changed about 9 months ago, and the boat has probably gone through about 100 gals of gas since that time. Problem is, the gas that was in the boat when I got it (which is when I first changed the filter) was of an unknown quality (probably had been sitting for quite awhile), so I'm hoping that I won't need to do the filter every 100 gals from here on out. Even if I do, they are cheap (cost me 10 bucks or so at West Marine), so, frankly, if that's what it takes to keep the boat running well, it's not really a big deal.

Not going to say that problem is solved for sure, but the boat appeared to be running quite a bit better after the change (immediate improvement to starting ease and smoothness at idle).

Re: 5.7 TKS fuel filter

When I held it up to the sun, it looked like there were "swirls" of something through the fuel. Not sure if that's normal or not,

Click to expand...

Nope, not normal,... that's the crud that's causin' it to lean out...

so I'm hoping that I won't need to do the filter every 100 gals from here on out.

Click to expand...

ya can't time it by the gallons used,...
You could change the filter, 'n pick up a load of crud in the 1st trip, or in 100 trips...

Re: 5.7 TKS fuel filter

Good to know, I'm just going to keep another filter on the boat all the time, they are cheap, and, if this proves to be a perm fix, not a big deal at all (shoot, they only cost what 2 gallons of gas costs!).

Thanks for the info about that not being normal. What would be normal when emptying out the filter? Should it appear to be clear (without an "swirls" of stuff going through it) gasoline? Or does gasoline always look like it has swirls through it (sorry for my ignorance)..

Re: 5.7 TKS fuel filter

Ayuh,... Gas is a light amber, clear fluid...

Swirls could be alcohol, or whatever..
Crud is crud,...
And water tends to look like globule's, that swirl...

Re: 5.7 TKS fuel filter

Well.. Problem is still there.. Have some more data to report though, perhaps it will help pinpoint the issue.

Ran the boat for 1-1.5 hrs on the new filter. Everything was great (no hunting, good power, etc). While running back home, ran into some nasty waves and, upon hitting a few pretty hard, the motor started to hunt and then eventually almost stalled. I stopped the engine, spun off the filter, dumped it, screwed it back on, and then restarted the engine. Engine restarted pretty easily, and ran for another 45 mins or so. Problem reared it's ugly head again, came off a plane and she started to struggle. Pulled the filter, dumped it, everything back to normal.

A few observations.

The initial "problem" on this trip absolutely seemed to be related to hitting the waves, the motor started to lug pretty quickly after that.
Dumping the filter seemed to fix the problem. However, I never tried just pulling over, waiting for 5 mins, and then restarting the engine, so I can't say that it wasn't just time that was resolving the issue.
Fuel didn't look bad coming out of the filter (but I didn't let it sit to see if it would separate).
Seemed that each "dump" of the filter resolved the issue for less and less time (with the new filter we ran for 1.5 hrs+, the first dump got us maybe 45 mins, the next only about 30).

I am not convinced this is a "water in the gas" problem, so, please, if anyone has some suggestions, let me know and I'll be happy to give it a shot.

Re: 5.7 TKS fuel filter

Easiest thing to do is run the boat off a remote can of fuel direct from the pump. See if it solves the problem. You could have a plugged up crudded up pickup in the tank. Isolate the fuel sytem by the process above and see what happens. I am suspecting you may have some carb issues also since it did it in heavy waves. A lot of sloshing around in the fuel bowl and maybe even a float problem. Try the can first.

Re: 5.7 TKS fuel filter

Seemed that each "dump" of the filter resolved the issue for less and less time (with the new filter we ran for 1.5 hrs+, the first dump got us maybe 45 mins, the next only about 30).

Click to expand...

Ayuh,... Each time you dump it, 'n reinstall it, you contaminate the Clean side of the filter...

You've definitely got a Fuel problem,...
Do as mpdive says to find where it is....

Re: 5.7 TKS fuel filter

Do you think that the "dumping it" is actually the resolution to the problem, or the are just coincident? I haven't tried just turning the engine off and sitting for 10 mins (about the time it takes me to dump it).

Back to my opening question. Do you think that putting a Racor with a petcock on the fuel line might be the end of my problems? I'm guessing (emphasis on guessing) that I've got more water in the fuel than the little filter can take. I've got 35 gallons or so in the tank, so it'd be a lot cheaper to put the Racor (and empty if a few times during a run) on there than to dump the whole tank (if, of course, that will be able to handle the amount of water I've got).

Weird thing is, the boat seems to run great for a quite awhile until this problem rears it head. Power is good, no hesitation, nothing (after changing the filter before this most recent run). That's why I'm thinking the problem is some water in the fuel, I just don't want to overlook anything else. Seems like a fuel problem (when I hit the waves it stirred up the water and dumped a lot of it into the filter, as an example), but.. I'm very interested in what others think..

Seems that the filter is doing the job of keeping the water out of the carb though; the boat ran great for quite awhile today, no hesitation/etc. So it doesn't seem like the water has made it there (again, assuming that's my problem), just plugs up the filter and the motor leans out and won't run.

Oh.. One other observation. If (when I feel the motor start to get cranky) I stop and rev the engine, it seems to be fine. As soon as I put it back in gear and try to take off, it dies out again. Seems that the load of the prop has something to do with it. If I wait too long (until the motor is really starting to lug), even in neutral it won't rev; seems like it wants too, then dies back.

Thanks again for all the help everyone, I really appreciate it!

Re: 5.7 TKS fuel filter

mjfink said:

Back to my opening question. Do you think that putting a Racor with a petcock on the fuel line might be the end of my problems?

Click to expand...

I believe the racor filter you are talking about is designed for outboards - not for I/Os. There is a safety concern with the plastic / clear bowls.

If you haven't split the carb apart yet, you need to. The chances are good you have some water / crud in the bowl of your carb.

You also need to clean out your tank. The wave action is a dead giveaway that you have a contaminated fuel problem.

Re: 5.7 TKS fuel filter

Don't over filter the fuel line. Every filter is a restriction. Too many and you'll have reduced fuel flow. If you have a junky needle and seat in the carb and hit a big wave, the float popping up and down can cause the needle not to seat properly. Additionally,when the float get's bounced to the up position it put's pressure on the float tangs, and it will over time change your float adjustment.

Re: 5.7 TKS fuel filter

Ok.. Sounds like the Racor external filter really isn't a good answer to this. Stinks, the filter is so hard to get to on my engine, requires a real contortionist to get in there and remove/replace it.

So.. In lieu of that, what would everyone suggest. I'm thinking of building something like this:

http://continuouswave.com/ubb/Forum3/HTML/012877.html

So that I can pump out the water from the bottom of the tank (I assume it's always right on the bottom after a few hours to settle?). Then change my filter again and give it another run. Is there anyway to get a "petcock style" filter for the engine (so that I don't have to keep pulling them)? How about a good way to empty out the filter (that won't mix all the crap back in)? Or is my best option to just keep running through the filters until the water is out of the tank.

I'm thinking that I might be taking on the water through my fuel sensor; I've taken that off a few times (for repairs) and it's right on the top of my tank (so would make it easy for water to intrude. Is there anything specific that I should do to make sure that connection is water tight? Something like the liquid electrical tape (I realize, not that, but something like it) to use on the gasket to seal it in? Or just replace the pickup entirely?

Re: 5.7 TKS fuel filter

mjfink said:

Ok.. Sounds like the Racor external filter really isn't a good answer to this. Stinks, the filter is so hard to get to on my engine, requires a real contortionist to get in there and remove/replace it.

So.. In lieu of that, what would everyone suggest. I'm thinking of building something like this:

http://continuouswave.com/ubb/Forum3/HTML/012877.html

So that I can pump out the water from the bottom of the tank (I assume it's always right on the bottom after a few hours to settle?). Then change my filter again and give it another run. Is there anyway to get a "petcock style" filter for the engine (so that I don't have to keep pulling them)? How about a good way to empty out the filter (that won't mix all the crap back in)? Or is my best option to just keep running through the filters until the water is out of the tank.

I'm thinking that I might be taking on the water through my fuel sensor; I've taken that off a few times (for repairs) and it's right on the top of my tank (so would make it easy for water to intrude. Is there anything specific that I should do to make sure that connection is water tight? Something like the liquid electrical tape (I realize, not that, but something like it) to use on the gasket to seal it in? Or just replace the pickup entirely?

Click to expand...

I would think about relocating the filter with a remote filter kit so it's easier to get to. Second, if it were my boat, I would scan ebay for a good price on a pack of filters and keep changing them out. Even if you change them out every other trip it would be worth it. I really don't feel you have accumulated enough water to justify tank pumping since you do use the boat. As strange as this may sound, if you have been running ethanol, keep running it for now and use an additive such as Startron in the fuel. Don't add regular fuel since you'll lower the E rating of the ethanol and drop even more water out of suspension. Keep the additives in the fuel and keep changing filters for a while and see if it cures up. Try to burn through a lot of fuel if you can by making many beer runs. Keep us posted

Re: 5.7 TKS fuel filter

Would you recommend something like this:

http://www.amazon.com/Permatex-8006..._3?s=automotive&ie=UTF8&qid=1317515345&sr=1-3

For the gasket that goes around the fuel sensor? I'm pretty sure that's where I'm taking on the water, so I'm going to pull it, pump out the bottom of the tank (see if there's visible water) and then reinstall it. Or should I just scrap it and get a new fuel pickup w/a new gasket?

Re: 5.7 TKS fuel filter

mpdive said:

I would think about relocating the filter with a remote filter kit so it's easier to get to. Second, if it were my boat, I would scan ebay for a good price on a pack of filters and keep changing them out. Even if you change them out every other trip it would be worth it. I really don't feel you have accumulated enough water to justify tank pumping since you do use the boat. As strange as this may sound, if you have been running ethanol, keep running it for now and use an additive such as Startron in the fuel. Don't add regular fuel since you'll lower the E rating of the ethanol and drop even more water out of suspension. Keep the additives in the fuel and keep changing filters for a while and see if it cures up. Try to burn through a lot of fuel if you can by making many beer runs. Keep us posted

Click to expand...

I'm currently using Stabil Marine in the fuel, think I should add the Startron to the mix as well?

I'm not going to pump the entire tank (there's no way there's enough water in there to justify that), but was going to build that little doo-hickey to see if I can get some crap out of the very bottom of the tank (where I figure the water is hanging out).

LOL @ the beer runs. I'm doing my best to burn through the fuel, and already have 2 spare filters (I think they cost about 10 bucks each at West Marine, maybe I can get a 10 pack of them at Amazon or something).. I just hate it where I can't "trust" the boat. Most of my time is on the ICW, and I'm often many miles from the dock. I think that this fuel thing is the source of the problem, but I really don't like having a boat that's not running well, it's just a lot of stress. I have SeaTow, so, I guess, worse came to worse, I'd just have to get a tow in, not the end of the world.. But not exactly enjoyable boating when you've got SeaTow on the line waiting for the engine to crap out.

Re: 5.7 TKS fuel filter

Sorry.. One final question. Just found this direct replacement filter from Racor that seems like it might work for me (and give me the ability to drain the water through a petcock).. Think it's worth it to try to go this way?

http://www.amazon.com/Racor-Divisio..._2?s=automotive&ie=UTF8&qid=1317517836&sr=1-2

Re: 5.7 TKS fuel filter

Maybe just a gasket if it's available. I would be leary of using any sealants since eventually they break down too. I think your on the right track here and don't get discouraged. A remote kit can make filter changes a breeze, and your persistance will pay off in the end. I had a friend simply take a piece of rubber hose and carefully place it at the bottom of the tank. He found a largemouth container and took a rubber tip blower and blew compressed air across the other end of the hose to create a vacuum. Then he just slowly moved the hose along the bottom of the tank to pull the garbage out. Worked great. We used to do it at the shop all the time to drain fuel tanks. Please no smoking while working around fuel.

Re: 5.7 TKS fuel filter

Well, the problem still haunts me. Was down on the boat today (new fuel filter) and ran for about 1hr just fine. Then the boat started to "stumble" off idle. Never took it up on a plane after that (no wake zones, blah), but it was still stumbling when I got it back to the dock. I've pumped the bottom of the tank (honestly, it looked like clean gas to me, still took out about 2 gallons though, just to be safe).

Didn't seem to get any "hunting" today, just a stumble off idle. I'm at a loss (and calling in the pros), but, if anyone has some ideas where I should keep looking, I'd be very interested to hear them!