F225 Won't rev over 2800 RPM

[BlueberryHill]

So, here's the background. Just bought the 2006 Southport 28TE with twin F225s. (2400 hrs) During my sea trial both port and stb ran up to 5200 RPM, during the official survey they both ran up to 5200 RPM under load. Boat get's delivered from Boston to Delaware and I launch at my marina (Indian River Inlet Marina), Stb engine starts and runs just fine, port runs for about a minute and dies...continues every time I start it. Got to my slip on the STB engine. OK, replaced port fuel water filter - no change. Replaced primer bulb - no change. Replaced the low pressure pump-fixed the running issue. Replaced cup filter (lots of junk present, some water) - still nothing over 2800 RPM. Now the port engine won't run under load past 2800 RPM. Drained VST tank-no change. Both engines run fine up to that point. *****ed for over 2 hours no problems at low RPM. Tried running 2800 again on the port engine-same issue. I'm suspecting the VST filter needs to be looked at and possibly the High Pressure pump. When running if I increase the throttle on the port engine beyond 2800 RPM, the engine pops back and the RPM's won't go up. Just looking for a confirmation that the next inspection should be the VST filters and tank. Injectors were serviced prior to purchase.

[cpostis]

So, here's the background. Just bought the 2006 Southport 28TE with twin F225s. (2400 hrs) During my sea trial both port and stb ran up to 5200 RPM, during the official survey they both ran up to 5200 RPM under load. Boat get's delivered from Boston to Delaware and I launch at my marina (Indian River Inlet Marina), Stb engine starts and runs just fine, port runs for about a minute and dies...continues every time I start it. Got to my slip on the STB engine. OK, replaced port fuel water filter - no change. Replaced primer bulb - no change. Replaced the low pressure pump-fixed the running issue. Replaced cup filter (lots of junk present, some water) - still nothing over 2800 RPM. Now the port engine won't run under load past 2800 RPM. Drained VST tank-no change. Both engines run fine up to that point. *****ed for over 2 hours no problems at low RPM. Tried running 2800 again on the port engine-same issue. I'm suspecting the VST filter needs to be looked at and possibly the High Pressure pump. When running if I increase the throttle on the port engine beyond 2800 RPM, the engine pops back and the RPM's won't go up. Just looking for a confirmation that the next inspection should be the VST filters and tank. Injectors were serviced prior to purchase.

I suspect you are leaning in the right direction.
Here's a link that instructs you how to check/clean the VST filter and tank.

VST Removal, Cleaning, Filter/Screen Replacement

[fairdeal]

Just looking for a confirmation that the next inspection should be the VST filters and tank. Injectors were serviced prior to purchase.

Definitely.
"while you're there"
- replace the "F-shaped filter" between the the LP pump and the VST
- inspect / test the pressure regulator that is zip-tied to the LP pump


and keep in mind that the injectors are "the end of the line" -
that they were serviced "already" doesn't mean they can't have gotten crapped up again from crap circulating in the system

[BlueberryHill]

Thanks for the fast reply. I have the "F" filter ordered along with VST filter and VST rubber seal. I have a new high pressure pump coming as well. Thought I'd just be sure to cover all the bases. I'll be sure to advise if this fixes the issue. Not looking forward to having to re-power this early in the ****... I have a feeling it's where the problem lies, as before I replaced the low pressure pump, it would run for a little while and if I increased the throttle, I would get the same pop back through the intake at low RPM when it ran out of fuel. I can watch the filter cup fill and drop when it's running now. I also can hear the pump running constantly after 1200 RPM... At idle, on 10 sec off 20 sec.

[BlueberryHill]

Change around the fuel lines at the RACORS. If the bad engine gets above 2800 RPMs you know which fuel line is causing the issue (could be a clogged fuel tank pickup).

On the bad engine, is the primer ball collapsing when under load at 2800 RPMs? Collapsing PB means you have a fuel restriction.

CaptSolo, haven't checked that. I did replace the primer bulb and it didn't seem to fix it...although if it is a restriction from the tank to the bulb a new bulb wouldn't cure the issue.

I guess it could have stirred up something in the tank during the road trip from Boston to Delaware...then again, wouldn't running boat also stir up the same stuff? One thing at a time...

Thanks again for the suggestion.

[99yam40]

If you found trash and water in a filter after the larger ones you have to wonder why the big water/fuel separating filters did not take care of that stuff.

if they had the injectors serviced not long ago I would think they were having problems before they sold the boat.

Monitor fuel pressures. if there is a restriction that will tell you where it is.

If you are getting water and trash in filters maybe be the tank needs draining and cleaning.

Could the fuel be old and bad?
another reason for draining and cleaning

[BlueberryHill]

You need two people to check for a collapsing PB. One at the helm with the throttles, and one watching the PB by the RACORS.

A PB will only begin to collapse at the 2800 RPMs under load. It won't collapse at idle.

Because the engine stalls after starting (every time), I wonder if it is some other fuel issue.

Can you keep it running by raising the throttles (pumping the PB?)?

A "miss" in the engine will cause an engine to stall after running for 1 minute. That means a bad fuel injector or two to me.

ALSO:V IMPORTANT: check and drain some gas/water from your RACORS EVERY time you use the boat. Water getting to fuel injectors in an engine... and you are done IMO. I check and drain off some gas from my RACORS after every trip. Really. Not every 6 months. every trip.

One of my RACORS collects most all my water because it has a lower pick up than the other two pickups. The two others are almost always empty of water.

By checking and getting out the water every trip, I usually end up with a 1/4 ounce of water in the plastic bowl - instead of a half glass full.

You might get most all all the water out of your tank by draining the Racors after every trip.

PS I just sent 6 used/bad F225 injectors off in a package to the company that fixed my last 6 injectors. The last 6 injectors he rebuilt, at a cost of $20 an injector, got rid of a minor miss that was causing a loss of power on the way up to 5000 RPMs (the engine would constantly stall after startup, and run for about 1 minute only). https://vid.me/O1cj

The injectors he rebuilt got the engine running so well I decided not to sell the boat. https://vid.me/WsWO

I have a good Yamaha mokanic (20 years experience) that works on my boat (it's not me). He cleaned the VST, cleaned a few inline gas filters before replacing the 6 injectors. The "miss" that was audible before was gone, and this port engine (in the video) tacks out to 6000 RPMs - without any hesitation on the way up there.

Here's another factor that may be part of the problem...the water filters are not the large Yamaha filters..they are the after market, shorter length filters from Sierra 10 micron. That being said, the Stbd engine runs fine. The stalling issue was before
I replaced the low pressure fuel pump. That issue has been resolved.

[pstephens46]

Short filters aren't terrible as long as they are changed regularly and you use decent fuel. Does Solo really get water in his racors after every trip? That would be a little concerning....

[fairdeal]

Short filters aren't terrible as long as they are changed regularly and you use decent fuel.

Exactly.

A filter canister that can only hold 50 mLs of water is perfectly adequate,

so long as you never get more than 50 mLs.


A filter canister that can hold a quart is useless if you feed it two quarts...

[pstephens46]

I personally get the largest one. Actually bought a Yamaha filter last time - $18.

[pstephens46]

Where is all this water coming from? That is the question. I have never found a drop of water in my filters. I dump the contents in a glass jar every time I change it.

[cpostis]

Where is all this water coming from? That is the question. I have never found a drop of water in my filters. I dump the contents in a glass jar every time I change it.

Here's where it comes from. Yea, I can be a smart donkey.

http://i1164.photobucket.com/albums/...psxrsts8kp.png

Now, how it gets in a boats fuel supply is another matter.

What we pump into our pump tanks is probably one of the main culprits. We need a consistently dependable source of good clean, water free gasoline to begin with. If questionable, test for water in a sample before you pump it in your tank.

Although this article is for Avgas, check this link on how gasoline may get in fuel before we put it in our boat tanks.
http://www.faa.gov/documentLibrary/m...r/AC20-125.pdf

What can we do to prevent water from getting in our fuel after it is in our tanks?

Gasoline water/filter separators will do their job to prevent water from getting to your engine to a point. I do get minimal water (maybe an ounce max, twice a year) in my filter/separator after a long period of time. If you are getting an excessive amount of water, the capacity of the filter/separator probably will let it pass.

Keep tanks reasonably filled to prevent condensation. Ensure gas fill caps are sealed/tightened properly (have you ever replaced the o-ring?). Ensure vents are properly installed, placed, and vent hoses not leaking below deck and connections. Avoid ethanol blend gasoline. Ensure access panels on top of tank are sealed properly.

Townsends like to use a product (K-100) that keeps water in suspension, I have not found the need for it seeing that I get only an ounce or less in my filter/separator. If the water is in suspension, it will not collect in your filter separator and will burn off along with gasoline.

Many boaters have water in fuel quality problems, I have not for a while (Knock on Fiberglass). I believe because of my awareness and minimal effort it takes me to prevent contamination.

[BlueberryHill]

I suspect you are leaning in the right direction.
Here's a link that instructs you how to check/clean the VST filter and tank.

VST Removal, Cleaning, Filter/Screen Replacement

Follow up to all the recommendations: Spent the better part of the afternoon replacing the VST filter, F filter and high pressure fuel pump in the VST tank...new O-ring of course. There was about 25% blockage in the filter element and some gritty residue in the VST tank. After cleaning and reassembly, it started up just fine, revved fine under no load...unfortunately it was too late in the day to take it out (I always like to have a mate that knows about boats on board during a check out ride...).

So, Took it out today for a test ride, wind blowing 15-20 at the Indian River Inlet Marina, both engines pulled strong up to 5100 RPM without hesitation, pops or misses.

[IMG]IMG_20160924_143437 by Charlie Seymour, on Flickr[/IMG]

Low speed operation was also fine...

Thanks to all for the suggestions and comments. If I run into the problem again, I know exactly where to look. This took a while, but it was all worth it.

[cpostis]

Great job! Glad to hear you're happy.

[rodbolt17]

5100 is still over propped.
those motors need to be able to turn 5700-6000 with that days load of gear,fuel and persons.