fuel vacuum

C

C-hop chop

New member
I have a 2006 cape cruiser 23. I have an issue with the vacuum between the gas tanks and the primer bulb. it takes a lot of squeezing of the primer bulb and switching the tank selector back and forth from tank to tank and cranking the 150 Honda engine, to engage the engine fuel pump to reduce pressure above the primer bulb to engine, before I get the fuel lines filled with gasoline. once the boat sits awhile usually longer than a day, the lines require the time consuming effort to refill the fuel lines again. I have replaced all the fuel lines to the primer valve from the tanks. replaced the pick up tubes, check to assure the anti syphon valves are working freely, and tightened all fittings to assure tight fits. disassembled the tank selector valve and reassembled it. I am suspect of the fuel tank selector valve possibly allowing gasoline to leak from one tank to the other, but you would think if both tanks are filled above the pick up tube it would maintain a vacuum anyway. The vents to the tanks are working properly also. I think the valve is the most likely culprit. Oh , and I did replace the primer bulb twice. Any one have an idea of what I could be missing? I just about washed up on the rocks exiting an inlet, before I realized this was occurring. thought I had solved the problem last year, replacing what I described above. But same issues again later in this years boating season. I would appreciate anyone's impute on this.
Marty
 
I had a Yamaha engine on a RIB. If I pumped the primer bulb 'til it was hard (as suggested in a lot of places) I would have problems getting the motor started. If I left the primer bulb alone, never had any problems starting.

On my C-Dory, the only time I touch the primer bulb is if I run one tank dry til the engine quits before switching over. And then it is just a couple squeezes to get some fuel back in the line.
 
yeah, that has been my experience with other outboards also. and I did the same with this C.C., but the engine stalls because some how the fuel is escaping from the fuel line. I presume back to the tank. I obviously have a leak somewhere in the vacuum portion of the fuel system, because I cannot detect any fuel leaking into the boat and the primmer valve is only pushing air till I go through the previously described procedure. I suspect it is the tank transfer valve, only because it is the only thing I have not replaced. I wonder if any one else has had issues in the past with these tank transfer valves letting air into the lines. I was also wondering if the fuel line length in these boats is too long for the primer bulb to work effectively? Should it be an electric fuel pump instead? Thankyou for your quick reply.
 
My fuel selector switch is very picky about where it is pointed. If it's not in absolutely correct spot, it doesn't draw fuel. If yours is anything like mine, I'm sorry. I'm not sure why it doesn't have a solid detent letting you know it's correct, but whatever.....terrible design :-(
 
Hi C-Whisperer, thankyou for replying to my problem. I have learned a lot from reading this web page, where you and others such as SoBELLE have helped solve issues with these boats. Good boats, just little corks here and there. Definitely a learning curve to keeping them working and to operate them properly.

Your so right about the fuel selector valve. may have to rethink the way this fuel supply is set up. could just place a T-fitting as I had read in a previous post and just add ball valves to open and close fuel access from each tank. do you think having the valve just a little off, as you mention, could allow the vacuum in the line to drop and empty the fuel back into the tank? I feel there is a conflict between the pressure above the primer bulb and the fuel pump in the Engine, having too much pressure that I cannot remove the trapped air in the fuel line below the primmer valve. all works good together, unless air is getting in somewhere. you would think that if air can get in, then gas would leak out. but I'm not seeing that.
 
Hi C-Whisperer, thankyou for replying to my problem. I have learned a lot from reading this web page, where you and others such as SoBELLE have helped solve issues with these boats. Good boats, just little corks here and there. Definitely a learning curve to keeping them working and to operate them properly.

Your so right about the fuel selector valve. may have to rethink the way this fuel supply is set up. could just place a T-fitting as I had read in a previous post and just add ball valves to open and close fuel access from each tank. do you think having the valve just a little off, as you mention, could allow the vacuum in the line to drop and empty the fuel back into the tank? I feel there is a conflict between the pressure above the primer bulb and the fuel pump in the Engine, having too much pressure that I cannot remove the trapped air in the fuel line below the primmer valve. all works good together, unless air is getting in somewhere. you would think that if air can get in, then gas would leak out. but I'm not seeing that.
 
I hate to muddy the waters but I have two Honda 150's on my C-Dory. The starboard motor starts and runs flawless while the port won't start after a long run and an hour stop. I have to prime the bulb several times to get it running and then it does fine until the next 'restaurant' run .

I have replaced the primer bulb twice with no luck and I don't have a tank selector valve. I gave up troubleshooting given the easy remedy.

Please tell us what your fix turns out to be :thup
 
I played around with it today. Im kind of embarrassed to say, but I never considered the external fuel filter, since I figured it was positive pressure. And if that was the problem I would see fuel dripping. well turns out that the fuel filter is connected between the tank distribution valve and the primer bulb. so it is negative pressure. Removed all the fittings and reapplied gas fitting sealant and put it all back together. had immediate pressure from the honda engine fuel pump, did not need to use the primer bulb to get a vacuum. not sure if that solved the problem yet, but sure looks like it did. Thank you for all the replies, good to exchange ideas, helps narrow the possibilities before getting your hands into it.
 
I took the cape cruiser out for the day, Monday. problem with stalling issue still persists. When the engine started to stutter stall at about 19 m.p.h. I checked the primer bulb it was still firm. Stuttering only happens when in higher R.P.M.'s I heard about older hoses deteriorating on the inside but still good on the outside. next step is to replace the hose from the primer valve to the engine. Only have about 25 hrs. on the external filter, but may as well replace that also. I will cut the fuel line apart to see if that was deteriorated in any way. According to the mechanic at the local Honda dealer, the filter inside the engine is very unlikely to be the problem I am describing. Not sure how he came to that conclusion, but I am not on the same page with him on that. But for now, with the cost of those internal filters, that will be one of the last things replaced. Any ideas or suggestions would be greatly appreciated.
stuck with stuttering C.C.,
Marty
 
C-hop chop":3fba2of5 said:
I took the cape cruiser out for the day, Monday. problem with stalling issue still persists. When the engine started to stutter stall at about 19 m.p.h. I checked the primer bulb it was still firm. Stuttering only happens when in higher R.P.M.'s I heard about older hoses deteriorating on the inside but still good on the outside. next step is to replace the hose from the primer valve to the engine. Only have about 25 hrs. on the external filter, but may as well replace that also. I will cut the fuel line apart to see if that was deteriorated in any way. According to the mechanic at the local Honda dealer, the filter inside the engine is very unlikely to be the problem I am describing. Not sure how he came to that conclusion, but I am not on the same page with him on that. But for now, with the cost of those internal filters, that will be one of the last things replaced. Any ideas or suggestions would be greatly appreciated.
stuck with stuttering C.C.,
Marty
Click to expand...

My Honda is a '08 BF90D so it is different. However, replacing the fuel filters on the engine itself was easy and not expensive.

FWIW, my engine had a problem with noticeable surging at mid RPMs. This was a problem with the ECU. Replacing the ECU fixed it. There was a service bulletin about this particular problem on my engine. However, the SB was only distributed to dealers and service centers. I found out about it online and had to point it out to the service center that was working on my engine. Even then, Honda Corp. made the service center jump through a lot of hoops to basically check everything else that could potentially be the problem before they were allowed to replace the ECU. Probably cost way more in testing and troubleshooting time than just replacing the ECU at the start according to the SB (ECU ~$800).

So the short answer is: If you know a good Honda service center, get them to check to see if there is any SBs on your engine that have not been addressed. Might fix your problem.
 
I just replaced the external fuel filter, had a lot of debris in the water bowl. not sure where it would have come from. Everything from the fuel tanks to the filter were replaced or rebuilt. good to know the internal filter is a reasonable price. The only local dealer, charged me that much just to repair a Honda 8 and still did not fix it. So I may order filters online. I hope its not the E.C.U., but surge or stuttering pretty much is the same thing, just a better description on your part.. If the filters don't fix the issue, then its off to a reputable Honda dealer to see about the E.C.U. Thanks for good advice Sobelle !
 
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