Anti-Siphon Valve

[jh141]

OK,   2012  22 trs,  200 sho.  I pump the primer ball up, it gets very firm, can not pump it anymore.  Stop and fish for an hour. Fire up and take off and very quickly it acts like its running out of fuel, pull back to idle and  pump the primer ball until firm and it will run for one or forty miles perfectly. Why does the primer ball go soft. I have replaced it once. Could it be bad again in a year or so. I have been told this may be caused by a bad ANTI-SIPHON valve ???????   Any insight or experience that might help me ??????

[Bamaskeet]

I suggest you check for a air leak at one of your two fuel filters.

[Wanaflatsfish]

10 hours ago, jh141 said:

OK,   2012  22 trs,  200 sho.  I pump the primer ball up, it gets very firm, can not pump it anymore.  Stop and fish for an hour. Fire up and take off and very quickly it acts like its running out of fuel, pull back to idle and  pump the primer ball until firm and it will run for one or forty miles perfectly. Why does the primer ball go soft. I have replaced it once. Could it be bad again in a year or so. I have been told this may be caused by a bad ANTI-SIPHON valve ???????   Any insight or experience that might help me ??????

Easy fix...above...

Antisiphon valves are a small valve with a round bead and a spring....many times, the spring will get clogged with a bit of crud and this is the end result.

they are easy to replace....

They are required on new boats....I took off my antiphon valve and replaced it with a straight valve on the pickup stem....you are in FLL ?  Go to McDonalds or BOW and they will have either the valves or the antiphon.....you .not supposed to do so (change to straight valve) to be NMMEA (i think it's the initials) certified but, I have a 1995 fuel tank, that sat for 5 years (still ok, no leaks so far) and it was full of gunk....it took me about 3 razor filters to get it right, even after I had it pressure cleaned....

DC

 

[Lap it Up]

12 hours ago, jh141 said:

OK,   2012  22 trs,  200 sho.  I pump the primer ball up, it gets very firm, can not pump it anymore.  Stop and fish for an hour. Fire up and take off and very quickly it acts like its running out of fuel, pull back to idle and  pump the primer ball until firm and it will run for one or forty miles perfectly. Why does the primer ball go soft. I have replaced it once. Could it be bad again in a year or so. I have been told this may be caused by a bad ANTI-SIPHON valve ???????   Any insight or experience that might help me ??????

Bad anti syphon valve would cause the ball to *** flat (restriction).  Just going soft is either air leak, bad primer ball, junk in VST or VST filter, water or junk in F/W separator.  It could also be fuel pump losing prime or going bad (not as high a percentage).  If you have access to a fuel pressure gauge you can run it off the Schrader valve and see what pressure you drop to when the ball goes flat.  If its been a year I would change the ball and separator and try it again.  Use an OEM mercury ball.   Its better than a Yamaha ball and all the aftermarkets and try and get it as vertical as possible.  Dump your old separator into a glass mason jar and check for water and junk. 

[jh141]

Thanks Bamaskeet, I have zero fuel spill or smell, but I think I will change them both again for reassurance.

Thanks Capt. Dewalt. I am in FLL. I think I will at least check the anti-siphon valve since its been eight years. Also will give me a look at the hose condition.

Thanks Lapitup,  I agree with your take on the anti-siphon valve causing the bulb to *** flat not going soft. Thats my understanding of how that system works but was not sure. I will order a Mercury Primer bulb this time and try that.  I went fishing the day before yesterday (Wed.) and had this issue twice. I just checked it (Fri.) and it is still very firm. It must be the check valve in the Primer Bulb. I have pumped the ball and drained the VST tank through the valve at its bottom when I changed the filters. Came out very clean as I would expect as it had to get through at least two filters.

When changing the spin on (racor) filter or filters does anyone do anything special to help purge the air out?  

[DonV]

I had a bad anti-siphon valve which almost stranded me 25 miles out. After I limped home and figured out what the problem was it was an easy fix. Take it off, put it on a vise and punch out the ball and spring, clean then re-install. My neighbor across the canal had the same exact symptoms you had, told me about it a day after he took to it the marina to fix. I said it sounds like the anti-siphon valve, he says, "what's that?" $250 later they figured it was the anti-siphon, took it out and threw it in the trash. Been perfect ever since. Your call.

On the Racor fill with gas first then spin on. Good luck.

[jh141]

Will Do.....Thanks Don !!

[Wanaflatsfish]

BTW, 

Here is what I found in the anti-siphon valve on my Master Angler

[Wanaflatsfish]

I went to the straight barbed valve on the top of the pick up

 

dc

 

[jh141]

Thanks DonV

Well My boat now does NOT have an Anti-Siphon valve. I removed the fitting that houses the valve from the top of the tank. I took a 3/8 dill bit and carefully drilled out the end where the ball is. The ball then came right out. I removed the spring, cleaned and deburred the fitting, applied some Teflon tape to the threads and reinstalled. Very tight in the console, but not as bad as I anticipated.

Thanks for all the help guys. Will test and report if this cured the problem.