no start/fuel issue

[teaklejr]

Have a 1997 Tigercat with twin 200 Yamaha HPDI's and seem to have a fuel issue. As I do every year I replace the spin on fuel filters, squeeze the primer ball a bunch of times and motors start up and run with no problems. This time around did the same thing, motors started on land fine, splashed boat and motors ran fine, idled out and after a few minutes port motor shut off and would not restart. Got back to dock pulled cowl off and noticed the port paper filter housing was not filled up. Squeezed primer ball a bunch off times and still nothing, replaced primer ball same thing. Pulled fuel line off the exit side of primer ball and squeezed it and i get nothing out of it, it does push air out every time I squeeze it. Made sure primer ball was oriented properly. Removed newly installed spin on filter and its empty also removed gas cap to see if it was vapor locked. I am assuming it has to be something from tank to primer ball. Question is inside these tanks is the line rubber from pickup tube up to the brass fitting that exits the tank? Wondering if it is then maybe it has just gone bad inside the tank. going back tomorrow to check more but just wanted to ask and see if anyone had any input.

 

[Halfhitch]

Sounds like your anti siphon valve may be stuck closed. If you still have them in the system this would be a good time to eliminate them. That would be one thing less to go wrong.

 

[teaklejr]

Sounds like your anti siphon valve may be stuck closed. If you still have them in the system this would be a good time to eliminate them. That would be one thing less to go wrong.

Was just doing some reading and someone else mentioned that. I had pulled up the round cover in floor to look at the fuel tank where the fuel exists and it just looks like a brass 90 degree fitting to the fuel line. Not really sure if it has a anti siphon valve or not. Going to google it and hopefully get an idea of what it looks like.

 

[Halfhitch]

You will notice that the 90 degree fitting is a two piece unit. The piece with the barb on it going into your hose and screwed into the tank fitting is the anti-siphon valve. It has a spring loaded check ball in it. You can replace it with an open, straight through barb fitting and still be within Coast Guard regs.

 

[DennisG01]

Stbd motor is fine? Separate tanks or one tank with dual pickups?

Pickup tube is not rubber, but could be cracked or clogged. ASV is a possibility. I'm personally a proponent of keeping them in place - they can be cleaned with brakleen (or just replaced as they're cheap enough). A caveat about replacing them... If any part of your fuel line is below the top of the tank, though, absolutely DO NOT remove it. The ASV - it's just a spring and a ball. You should be able to blow through it towards the tank.

Rubber fuel line could have failed internally, as well (or even have a hole in it). Try a short piece of new hose along with the primer ball to see if you can get fuel coming out.

EDIT: AS"V", not AS"F"... not sure why I originally typed ASF

 

[Halfhitch]

The ASV is spring loaded toward the tank. When fuel flows it compresses the spring and lifts the ball off its seat. Any flow toward the tank will be blocked since the spring will return the ball to it's seat along with the added force of any back-flowing pressure.

 

[DennisG01]

Half - you are correct with the operation of the ASV. Honestly, I'm not even sure why I wrote what I did in the manner that I did. It's totally not what I meant. I meant to say that if the ASV was partially clogged, then it would stay partially open (since it wouldn't seat properly) and you would be able to blow through it. I guess watching Designated Survivor at the same time I was typing was a bad idea!

Jr... another good test is to simply run the failing motor on a portable tank, plumbed in at various places - helps to eliminate variables - and then you can fine tune from there.

 

[seasick]

if the anti siphon valve is stuck closed, the primer bulb will start to collapse and you didn't say that it did.

If you squeeze the primer bulb and it does squeeze but no fuel flows then you either have a problem with the tank pickup, a bad fuel line( leaky but not blocked) or more likely an air leak in the plumbing. Recheck the spin on filter, you may have some old gasket that was left on the flange or the filter is not seated correctly.. It is possible that the primer bulb is bad but I don't think so based on your observations.

 

[teaklejr]

Going to boat in a few minutes and check it out. I am guessing right now it will be something with the fuel line or pick up. Since my new primer ball does not stay collapsed when squeezed I don’t think asv problem.

Boat does have separate tanks for each side. I will post hopefully good news later when I get home.

 

[seasick]

Going to boat in a few minutes and check it out. I am guessing right now it will be something with the fuel line or pick up. Since my new primer ball does not stay collapsed when squeezed I don’t think asv problem.

Boat does have separate tanks for each side. I will post hopefully good news later when I get home.

You mentioned that the port paper filter was not filled. Was it partially full or was it empty? It is normally about 3/4 full. If empty, the gas was sucked out and at least you know the fuel pump is working. If totally full, it may not be seated correctly and has an air leak.
As said, check and reinstall the spin on first. Then look for broken and leaking lines.

 

[teaklejr]

Thanks for all the reply’s it ended up being the spin on filter housing had a little bit of buildup where the filter o-ring seats. Pulled the housing off and used super fine sand paper to clean it up and now is back up and running. Always nice when it’s a cheap fix which is uncommon on boats.