Rodbolt 17 please help!!

[boscoe99]

Seems you did not tell the truth on this post if you did not replace all of the fuel lines.

Are you sure the motors are plumbed up on separate tanks or are they on valves that you can switch them around to the different tanks?

Seems there is a common place that both motors share like a valve maybe if both show signs of air bubbles and I would not think twin motors could not be run on the same tank when needed

And I do not think sucking air would cause the 40 to drop to 0 immediately when key is turned off, so maybe more that one problem

Who can know what to believe?

This post started with the motors (both of them) running just fine for long periods of time. The problem was stated as being a hard restart issue after they (both motors) had been shut down for a short period of time.

Now we have air in the fuel line, a loss of fuel pressure immediately upon the motors being turned off, loss of power when accelerating, primer ball failing to get firm and God only knows what else. And, it is now unknown if the problem is the same on both motors or only one.

Incorrect info in, incorrect info out. Does the term "a dog chasing his tail" come to mind here?

[Bilge Rat]

Does this boat have a tank selector valve?

The primer bulb is still collapsing on at least 1 motor or do both bulbs collapse?

The motors died soon after leaving the dock in one post so the problem is not only after a 30 mile run.

Sounds like the vacuum reading was when running on the portable tank not the tanks that are suspect if so that info is useless.

Get the story straight. You are only checking what is easy to get to.
Start at the tanks and replace the 10yr. old hoses check all fittings etc.
Use good hose, get rid of the clear stuff.
Pulling new lines is easy if you can't do it get a mechanic.

When you have completely gone thru the fuel lines then the fuel pressure dropping to 0 upon motor shut off can be addressed.

If you want a WILD guess here goes, When the tanks are full the motors may run. As you use fuel the level drops making it harder to pull out because of a restriction OR a vacuum leak. That does not explain the pressure dropping to 0.
You asked and got answers now do what has been suggested completely before jumping to trying another idea.

Sorry for being blunt but the people on here want to help, they are very good at their professions. Do your part, give good information and follow thru on advise given and your problem will be located.

[dorado42]

ok..first off BILGERAT I did check the tank vent -- no problem, I did check the pick-up (as to see if there was problem with screen on end or broken) neither of these helped. You also suggested "vapor lock" which it is not (problem occurred and did not repeat itself with portable gas tank. You said to report back and now I have and you accuse me of not being truthful. Well maybe if you explained "checking" things better I would noticed that the fuel pick ups have an air leak, did not to check for that. I never said the gauge dropped "immediately" to 0. I know people on this site are good at their professions that is why I came here. There also was no mention of the problem happening at the dock, it has been clear it was only after running the boat offshore. I have tried to do as told and report back. the only thing I was unclear about was the one section of fuel line I could not get to due to being "foamed" into side of hull. I apologize for that.

[dorado42]

CAPTSOLO...thank you for your advice to run the engines on portable tank with clear fuel lines. This definitely helped distinguish whether the problem was engine related or boat/supply related. THANK YOU!! The clear hose idea was also good because it showed there was air coming from the tank/supply source. I am going to replace the pick up tubes to see if that allows NO air bubbles in the fuel/supply line.

[dorado42]

The problem was stated as being a hard restart issue after they (both motors) had been shut down for a short period of time.

BOSCOE99....not sure where you read this, but this statement was not made in reference to MY problem...

Now we have air in the fuel line, a loss of fuel pressure immediately upon the motors being turned off, loss of power when accelerating, primer ball failing to get firm and God only knows what else. And, it is now unknown if the problem is the same on both motors or only one.

These results were from what other posters advised me to check. If the post is confusing to you, please do not reply with pasive aggressive belittling comments. NOTHING was stated to mislead anyone, and I was simply trying to explain problems I was experiencing thorough enough to help those WILLING to help over the computer (not in being in person to see/hear the problem first hand). SO your suggestion of Does the term "a dog chasing his tail" come to mind here? is somewhat correct due to it is a fuel problem. I can say that CAPTSOLO and RODBOLT17 have been helpful and understanding...maybe you should more of their post!!!!

[99yam40]

So do you know if you are getting air in fuel lines on both motors?

Sucking air can cause the primer bulb to not get firm, as it is not pumping just fuel.

Do you know if both primer bulbs do not firm up?

You stated "...the HP gauge was 40 psi....when key turned off pressure would drop to nothing...would jump back to 40 psi as soon as key switched on"

So, Does that mean pressure drops immediately or after a few minutes?

[dorado42]

The air is in both fuel lines....seems to be worst in Port line. I am guessing the fuel pick tubes are bad. I did get a chance to pull the port tank fuel pick up tube and could not see any holes are anything that I could tell was wrong. When I tried blocking the screen end with my finger and blew air into the pick up I tell air was leaking out but was unsure where at (may be a pin hole) just going to replace it and see if it fixes it. I already changed the anti siphon and made sure all fittings had permatex (to help woth air seal). I will get new new pick up tubes on Friday and post the results after I replace them. I can't really see where else air could get in the system (clear hose clearly shows air coming into the line about 6 inches past anti-siphon valve....THANKS!!!

[99yam40]

so you have not said if there is a way to run each motor on the different tanks.

Is there any valves involved?

Seems mighty strange to have both pick up tubes to go at the same time

And no comment on the pressure drop?

not real sure how permatex does in gas lines , might be you used wrong one

[dorado42]

The motors are each on their own. There are two independent tanks, two independent fuel lines, two independent racors, etc. The fuel pressure drop is gradual. The gauge read 40 and then slowly went down (like it was leaking down). There are no valves involved at all. I agree it is strange, that BOTH the pick ups would go bad at the same time. I just can not figure what else would be causing air to get in fuel system. The only commom problem is that I replaced both anti-siphon valves when first first started acting up. Any idea what else would be allowing air to be getting in the system??? I used the permatex to put on threads of pick up tube to seal it to tank....I used the permatex to seal the anti-siphon to fuel pick up....what else would would you recommend....I do not like using teflon tape near gas!!

[dorado42]

99Yam90 stated "Sucking air can cause the primer bulb to not get firm, as it is not pumping just fuel." I guess this is what I was explaining when I said the ball was collapsing when the motors would stall....not that they were flat (collapsed).....just very soft and would return to round slowly.

[dorado42]

ok just had a thought as I was explaining the problem to one of the guys I work with; I was telling him about the fuel pick ups and how they both could have started leaking air at the same time. Then I remembered, when I replaced the anti-siphon valves someone told me to check the pick ups since I had to change the anti-siphons. The pick up tubes have small screens on them that are "crimped" on the bottom. When I took them out of the tank (last time) I remembered the small crimped piece got stuck when I pulled it out and I think I might have bent the crimp part and that is where it is getting air in the pick up tubes. I was trying to be preventative and check everything and may have caused the problem and not realized it. I will check tomorrow and report back

[99yam40]

The pick up tubes have small screens on them that are "crimped" on the bottom. When I took them out of the tank (last time) I remembered the small crimped piece got stuck when I pulled it out and I think I might have bent the crimp part and that is where it is getting air in the pick up tubes.

If the screen/crimp is below the surface of fuel it can not suck air

[99yam40]

I guess this is what I was explaining when I said the ball was collapsing when the motors would stall....not that they were flat (collapsed).....just very soft and would return to round slowly.

Even if sucking air the bulb should return to round quickly if there is not something restricting it

[99yam40]

The motors are each on their own. There are two independent tanks, two independent fuel lines, two independent racors, etc. The fuel pressure drop is gradual. The gauge read 40 and then slowly went down (like it was leaking down). There are no valves involved at all. I agree it is strange, that BOTH the pick ups would go bad at the same time. I just can not figure what else would be causing air to get in fuel system. The only commom problem is that I replaced both anti-siphon valves when first first started acting up. Any idea what else would be allowing air to be getting in the system??? I used the permatex to put on threads of pick up tube to seal it to tank....I used the permatex to seal the anti-siphon to fuel pick up....what else would would you recommend....I do not like using teflon tape near gas!!

So, if one tank runs out of fuel before the other one , you are down to one motor and no way to transfer fuel to other tank or run both motors off of the tank that has fuel?

The replacement of anti-siphon valves happened right before the sucking air was discovered, I would be looking hard at that area

Just Need to make sure the sealant used will not be dissolved by the fuel

[dorado42]

Yes it is true that if one engine runs out of fuel, there is no way to transfer fuel from one engine to the other. I had a problem with the port motor as the first sign there was a problem. I checked the anti-siphon valve and it seemed to be the problem. It was recommended what I do to one motor I should do to the other, so I replaced both anti-siphon valves....next time out I had the problem. I guess my question is can the anti-siphon valve be allowing air into the system even though it is new. It does seem when I take the fuel line off the outlet side of the primer ball and compress it, then place my finger over the end and release the ball, to create vacum, then repeat, the gas/air seems to go back to the tank when I release the ball. I know it is hard to explain, but I am sure the direction flow on the ball is pointing the correct way!! I know I need to just go run the boat!!!