Performance question F31 1971

[LSP]

Bill .... glad to hear all went so well. A couple minor set backs keeps it exciting. Take care and enjoy the remainder of your journey.

[ready123]

Glad you made it OK in the end. Would GPS charts have helped keep you off the bottom?

the boat performed fine, except I had a small problem with fuel diversion from one tank and the other, for some reason my starboard engine was not getting enough fuel from the tank, so I quickly opened the petcock to divert all fuel from all tanks to both engines, basically open all valves and either engine could feed off either tank. Ill look into that this weekend, Im not to concerned, it could be like Tom here mentioned, a faulty check valve or something to that effect, I was considering electric fuel pumps, but Ill see .

I don't think you need the expense of electric pumps.
Your situation sounds like partially blocked anti siphon valve on the fuel pickup at the tank... the symptom for that is engine runs fine at low revs but increased fuel demand of higher revs causes fuel starvation. Using fuel with any ethanol works as a cleaning agent on the tank (among other problems I won't go into here) and so can add solids that plug the anti siphon. I ONLY use premium fuel with no Ethanol due to the numerous problems it causes in marine use.

we were moving alont at about 15 knots, and I just dont see how you guys claim 25 mph out of these boats,, man I feel like I was beating the hell out the those engines,
maybe due to my job(mechanic,, ) I just know to much,,,lol
anyway,
whats the deal with the steam coming from the exhaust, not excessive, but it concerned me a little, Bill truely out of control

How many rpm were you running the engines at to give you those concerns. They should sound fine at 3000 rpm when in good adjustment.
What about attitude of the boat... running bow down? Engines in Sync etc: all this adds to a smoother running attitude.
Other F31's owners can add how they need to trim their boats on plane. My F32 needs to be bow downish to get bow wave just forward of mid cleat location as viewed from the Fly.... that requires quite a good amount of down tabbing.
How hot were the engines running when you say you saw steam? Exhaust gasses are always clearly visible on these above water discharge designed boats.... more worry is when they look Blue or Black.
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[guglielmo6160]

well Im not really sure it was at high rpms, but all I can tell you is if I waited a minute or so the engine would start and run fine, till about 2000 rpms, and then shut down like it was running out of fuel, it did this a few times as we were in cruising situation,
I felt as if the engines were not running at full capacity, being an auto mechanic for my entire life, I just was under the impression the engines were in a situation where they were not running at the best potential, ,
the port engine would not go past 2500 rpm, but ran smooth and no issues with pressure or temperature, , maybe the throttle cable, etc, I didnt get into that yet, the starboard engine was running fine, with the exception of the fuel starvation problem,
Im gonna add some more fuel in the am, to get it to my final destination, and then go through the fuel system to find out whats going on , I can tel you that I didnt get into the systems at all, but the engines are strong, tight and probably need alot of fine tunning,
for example my throttle levers were not operating in unison, as they should both be aligned at an approx rpm together,
one question I would like to ask , is do you think the marine engines will not tach out higher because of fuel starvation? I mostly deal with fuel injected engines, not carbed, one sympton also was the port engine was acting like a spark plug was cutting in and out as well, maybe one of the plugs, were fouled and or wire etc.
In summary, I just think they were capable of alot more than they were giving me.
My main objective was to get the boat to its home port, this winter I will deal with all the quirks, but overall I am happy with my boat, and the engines,
the previous owner hardly took it out and probably wasnt even aware of the situation , I gave it a good thrashing yesterday,,,lol and another three hours tommorrow,
Im going to focus on the interior this winter, like the carpeting, woodwork, creature comforts, etc, like tv, radio, and then move on to the mechanicals and finally the cosmetics, like a serious cleanning and bottom cleanning .
I was also given two spare props which look to be in great shape, but will probably send them out to have them looked at,

Oh, I forgot to mention, I am a big fan of electric fuel pumps, I like the idea that they prime the carbs, rather than having to crank and crank in a fuel out situation, although your not suppose to run out of fuel, it does happen , and I just dont like the rubber diaphrams used in mechanical fuel pumps,
they are not that expensive, and I can set up a system, that I can choose mechanical or electric, with diversion valves,
I kinda like that idea, and can you tell me a little more about the syphon tubes, or check valves, Im not familiar with their use , or the advantages or disadvantages of using them,
I have two tanks, round cylindrical
one in front of the other, (dont know their capacity either
I dont even know which one feeds which engine,




Keep the info coming, its great

[mr elevman]

as for the Metedeconk river (stream)that is very common here a little west wind and you have to be very carefull and yes thay do remover the sticks in the winter in the rivers and the bay due to ice once a pon a time the bernagat bay woulf freeze to the point people would drive across it but that hasent happened in 10 - 15 years thank you globel warmming

[Peter]

I'm soooo jealous your on the water,even if you are freezing your buns...hope the rest of the ride continues with little or no suprizes...[which as you say is part of the game...]

[MattSC]

Glad to hear that you made out OK. The trip up the hudson should be alot easier. Do you know when the last time the fuel filters were changed? If it hasn't been recent, it might be worth giving it a try. Have a safe trip tomorrow,
Matt

[prowlersfish]

Bill , glad to hear all is well .

[ready123]

and can you tell me a little more about the syphon tubes, or check valves, Im not familiar with their use , or the advantages or disadvantages of using them

They are anti-siphon valves... basically they are a safety check to ensure that if the fuel lines broke that the fuel would not siphon out of the open end of the hose.
I'm sure you can see how hazardous having fuel gravity flowing into the bilge would be at any time, underway or at the dock. Basically a spring loaded flapper that only opens when the suction is sufficient (pump level rather than open hose/gravity level) to allow fuel to pass up the hose. Crap can get in behind them causing them not to be able to open fully and so causes starvation at higher demands.

Sounds to me like you need to get your engine mechanic hat on soon and get those engines tuned up..... points, spark plug wires, plugs, timing etc: all need to be kept correct to allow the full torque of the engine at any rpm to be put out to the props... that is the nature of boats, lower power is immediately noticed unlike with the average automobile.
Many more people drive poorly tuned cars than they should boats.

[guglielmo6160]

Ok, just made it back home after the second leg of my 85 mile trip,
all is well, and no issues, engines ran fine,
still have to sort out this problem with the tanks, seems to only draw from the rearward tank, no matter where I put the valves,
Ill get into it more this coming week,
Im sure its not a big deal,
the boat behaved real nice, and all is well

[prowlersfish]

Glad to hear it Bill. good luck on the fuel issue , I have seen proplems with the check valves as noted also check the norm ,filters , lines etc. checed for pluge fuel vents the fuel tank pick up could have a screen that could be pluged up . and who knows what the last owner(s) may have done .