Fuel Filter Change - Priming

[ROBERTH]

Hi folks, getting ready to change my fuel filters. Ordered the SS heads and Yamaha 10 micron filter kit from SIM.

Question I have is this:

Since there are no Primer bulbs on this setup for the Yamaha 200 HPDI on my 25 Grady Sailfish, I am unclear how I will prime/fill the filters.

The switch on the dash panel is the engine prime button, but does this prime from the tank or from the motor? Trying to figure out if it is a pull or push.

Thinking if it is a pull, it will be harder to get a prime and just wanting to make sure since I hear air to the lower fuel pumps on the Yamaha is not a good thing.

 

[bayrat]

Best advice that I can give you is to fill that Yamaha filter with fresh fuel before you screw it on. To do otherwise could leave you open to potential priming issues and workarounds . I followed that advice when I did mine and it was a snap.

 

[Tucker]

General consensus with those HPDI's over at THT is to run the 2-micron Racor. All the filters under the cowl are 2-3 micron and you want to catch any crap before it reaches the engines. Change them every 75-100 hrs. Recall one guy saying to put a 2-micron filter between the boat and anything that has HPDI written on it. They are very sensitive to clean fuel.

 

[Tucker]

Like Bayrat says, fill the filter with fuel and pump the bulb till it's hard (love that talk). DON'T screw the filter on too tight or the rubber casket will distort and you'll have a vacuum leak.

 

[Parthery]

I always run the engine and warm it up. Then change out the filter. Once the new filter is on, I start the engine again and let it run for a couple minutes. The fuel pump will fill the new filter up.

 

[ROBERTH]

All good and valid points!

I ordered the heads that come with filters for now. I figured out the original owner has 25 micro filters on it! Geez! So going to 10 will be a good thing, but after I clear the budget, will spend the additional to add the 2 Micron's with bowls. That will be another $120 clams I need to cough up, but realize it will be the right thing to do. I am getting some warnings on using the 2 Micron's though due to fuel flow only being 60gph and these engines will use potentially up to 40gph at wide open, so that is cutting it close if I have a lot of larger garbage in the tanks. So, thinking running the 10's for now and in approx. 50 hours switch over to 2's.

Motors only have 190 hours now on them, so hoping not too much has already gotten into the 2 micron's on the engine. Assuming the 2 Microns on engine are after the low pressure pump but before the mid pressure pump since I hear that the low pressure pump can't handle loss of fuel.

Think it will be a good idea to change them out this fall just to make sure they are not restricting and that way I will know that the pre-filters in boat will catch stuff before it gets to the engine.

 

[Tucker]

No way that motor is burning 40-gal hr WOT. Maybe combined twins, then each will have it's own filter. Guys with 250 OX66's are running these without problems all over New England and they're not having any problems. That restriced flow thing is overblown. Change filters every 50-100 hrs depending on condition of tanks and you shouldn't have a problem. Have fouled gas get to those HPDI's and you've better have deep pockets and get to know a Yami tech. If the restriced flow thing was real I don't think Racor would make the filter, they're a pretty stand up company. Too me they're cheap insurance.

 

[ROBERTH]

Gotcha. Was basing that on the Performance Bulletins on the Yamaha Website. Boats with Twin's in that class of motors were pretty consistent at WOT with just over 40 gph consumption. I am guessing the 200 HPDI's are somewhere in between these 2 tests, but more near the 225's than the 150's. It was more consumption than I would have imagined.

But, unlikely I will run her that hard.
Yamaha Bulletin: 23 Gulfstream with twin 150 HPDI's: 30gph max per chart below.
RPM MPH GPH MPG Db
1000 5.5 3.2 1.72 64
2000 8.3 6.4 1.30 76
3000 14.5 10.9 1.33 83
4000 33.35 14.1 2.37 84
5000 41 21.3 1.93 89
5600 47.4 30.2 1.57 94

265 Express with twin 4 stroke 225's: 42gph at WOT:

R P M M P H G P H M P G D b
1000 4.5 2.9 1.55 64
1500 6.9 4.1 1.68 69
2000 8.7 6.0 1.45 71
2500 11.4 8.6 1.33 77
3000 18.5 10.3 1.80 80
3500 28.7 13.5 2.13 81
4000 33.0 16.9 1.95 81
4500 37.8 21.4 1.77 83
5000 42.4 27.5 1.54 84
5500 46.6 34.7 1.34 88
6000 50.5 42.3 1.19 91

But, I do agree and will go for the 2 Micron's and make sure I keep track of hours used. Might be a good idea to change every 50 hours. I have no idea what condition the tanks are in, so when I remove the 25 micro filters, hoping I can see into them and see if there is any visible junk. If so, then I know I have crap in there to clean out.

One thing I have noticed is that Grady is using the Rubber fuel lines. Seems the ethanol can break those down more. My old Seadrive motor has those gray colored alcohol resistant fuel lines. I had removed the one recently that was original on the boat and was 25 years old, and it was still like new! Inside and outside was in excellent condition. So, thinking a project coming up this winter will be to replace all the rubber lines with the gray stuff.
Anyone done this yet? Thinking that if the rubber lines are disintegrating inside, that will help kill the filters and engines over time.

 

[Tucker]

Combined 40GPH sounds right. 2-tanks, each should have it's own filter. Hmm you got a 25' Sailfish, Is that like a '94 or '95? Not sure what lines they have in there, but the fuel lines on my '98 look fine. That's an interesting question though, anybody have them go bad from the inside and flake off rubber bits?? Can't hurt to replace. You doing the fill lines also??

 

[ROBERTH]

It is a '92 model. Not sure how hard it would be to get to the fill lines, but that is a good point. Guess when I start that project, will dig into to see if they are accessable. Pull up the floor plate but not sure how hard to get over to the side to pull it through.

It has twin filters in the transom. Easy to get to. Dual tanks , dual filters.

Guess I will see the condition when I replace the fuel heads with the new SS one's I am getting from SIM. Not sure if I will get them in time for this weekend, but if not no issue. I have enough other stuff to work on until they get here.

 

[BobP]

On the HPDIs, make sure you prefill the filter elements and squeeze bulb the motor until hard and needle valve closes, don't run VST tank dry, the electric fuel pump is in there and gets it's cooling from the liquid.

The Racor 2 micron filter elements of the merc type filter head are a few bucks difference per vs. 10 micron, and are physically the same size and fit same clear bowl and head. I believe the racor heads may not be stainless.
Meohler (used to be Tempo) sells the stainless heads for the merc / siera traditional canister gas water separator filters, and racor sells a retrofit conversion incl 10 micron filter and clear bowl. Filters are way less than 30 bucks per as I recall, either 10 micron or 2 micron choice for the element later both fit equally.

I've used the 2 microns for a season and it doesn't catch the sodium sulfate, meaning it is formed after the filter in the motor and the VST filter catches it. It is not forming in the ship's tanks or at the dock station tank. Too bad since the racor is a monster pleated filter vs. the tiny flat surface VST filter. At least the VST filter is servicable by DIYers.

 

[ROBERTH]

Thanks BobP, the problem I have here is that there are no Primer bulbs on my boat. It appears that the primer is electical only.

So the only thing I know to do here is to prefill the filter, then prime up and start the engine.

One post recommended that I run the motors first to get fuel into all areas, then change the filters and prime and restart. That makes sense to me.

Maybe I should consider installing some primer bulbs just after the fuel filters! But maybe the electric primers work the same way. Dunno.

By the way, here is the link to the SIM site for the SS filter heads! http://www.thehulltruth.com/shipyard-is ... lable.html

 

[BobP]

The SIM yamaha head looks like my old tempos but may fit a different filter not the merc/sieras, whatever.

You can use the electric boat primer all the same, you are better off prefilling canister with fuel before threading up into head. If VST was drained, hold switch on primer for 30 seconds. It is a low pressure pump and can do no harm, meant for carbureators.

When you get a chance, nix the electric primer it is a potential source or undetected air leaks into fuel system - been there done that. You also get a freebie panel switch position out of it.

Add a Yamaha squeeze bulb, squeeze while holding it with arrow up, for the HPDI you will only need to use it after the VST is drained or new filter cansiter. Not again, the motor has two lift pumps to pull fuel in as long as VST is filled as normal.

The squeeze bulb gives an added feature of determining fuel restrictions ahead of bulb (incl a loaded up racor filter) with a simple test, not so with electric primer.

 

[BobP]

By the way, modern fuel lines are black color and rated for ethanol too.

 

[Tucker]

By the way, modern fuel lines are black color and rated for ethanol too.

2nd that, mine are black and have a rating, I forget what, but it's the same as current except the rev. Mine are rev 2 or 3, current hose is about rev 9 and looks the same as mine, not sure of the difference.
Bob, what the heck is Sodium Sulphate?? Little pissed about that. Racor came out with this gas only filter as an almost end all to catch deposts released by ethanol cleaning the fuel tanks.
Don't now about all the hub-bub with the stainless heads. Painted ones lasted this long, bet the stainless is expensive. Got an old girl there, sounds like she's gonna need some love (money).

 

[johnnyboy]

I just changed 2 fuel filters on my 99 sailfish ox66 yamis. I had 10 micron on mine from previous owner and replaced them with the same, is 10 micron okay? Also, im new to these outboards, I hear there is fuel filters inside the engine, any online tutorials??

 

[Tucker]

Well, there is a small engine mounted filter that's easily changed. But, you have a screen filter on the bottom of your HP fuel pump and filter screens in each injector. IMHO I would replace with 2-micron Racors. I've been bit twice with with fouled engine parts caused by the detergent effects of ethanol. a 1999 & 1998 boat both Grady's

 

[ROBERTH]

Ok, I was able to get the new SS filter heads and 10 microns installed. I prefilled the filters and all looks very good. What a difference. My old one's were really nasty.

I took the cover off motors and used the electric primers and did not notice any air bubbles in the clear fuel tank on the side of either motor, so seems I had no air in the system to speak of.

Started the motors and all was fine, still no air bubbles, so looks like prefill is the way to go and somehow the system purges what little air was in there.

One thing is I am not sure if those huge canister looking things hanging just below the filters is the actual electric fuel pumps. They are quite large, but since the fuel lines run through them, guess that is what they are.

So Bob, you say bypass them all together and install the primer bulbs. Why would I really need to do this? They seem to work very well. Is this something that is not installed with new boats using HPDI motors? Sure is nice to push a button and go. All the fuel lines actually look very good. But will replace them this winter as a project just to ensure they are ethanol safe.

 

[rexicon]

Pull the fuel line off under the cowling and use a Mityvac to prime the system.

 

[BobP]

If there are wires going there, they are fuel pumps.

You don't have to do anything with them, the point was that they are no longer needed as you never have to prime the HPDIs except after servicing VST tanks where the hand squeeze bulb can get the job done easily, and the pumps can be a source of primarily corrosion related problems from the damp environment back there in the bilge. Squeeze bulb is uneffected by moisture and can readuly show visually an obstructed fuel system or loaded up fuel filter needing replacement.

With the HPDIs, Etecs, and all modern motors 2 or 4 stroke, you turn the key and go, just like in your car.