YTH23V48 Fuel Weirdness

[c1916]

I have an old YTH23V48 that I leave in storage with the snowthrower attachment in place for winter use. I start it up once a month to stay on top of any issues.

This month, she wouldn't start for me. Cranks fine (battery is holding a full charge). Won't turn over. I notice the fuel filter is dry. Swap out the fuel filter and fuel pump. Try again. Still nothing. Looks as though no fuel is flowing through the line to the filter, pump, and engine. There's a solid gallon+ of fuel in the tank. The line from the tank to the filter is clear and flows in both directions if I blow or suck on the hose.

Could it be the vacuum isn't creating enough "pull" to draw fuel through the hose to the filter and beyond? If that's the issue, does anyone have a suggestion on next steps to resolve the matter?
Am I overlooking something else that could be the cause here?

Appreciate your thoughts in advance.
Jeff

 

[c1916]

I'm going to bump this one time. The old YTH23V48 is used only for snow throwing, so it's now or never on getting it up and running.

Everything in the above post is still accurate. I went out again today and made sure all of the lines are clear (no blockage or impediment), fresh fuel, oil at the proper level, battery well charged. All of the lines are in good shape (not brittle), but there is never any flow from the fuel tank toward the filter let alone getting beyond the filter to the pump and into the engine. It seems like it has to be vacuum related, but I can't find any videos or notes on next steps in this scenario. The vacuum hose has been removed, inspected and replaced, it is not clogged with oil or detritus and it has a good seal on the valve cover.

Even though this old mower is only running on one cylinder it has been enough to get me through the snow removal season in Chicago for the last 3 years. Shooting for just one more.

 

[Rivets]

Remove the fuel line from the carb and SLOWLY pressurize the tank. We want to see if fuel will flow from the tank, though the pump and filter. If it does I suspect that the float needle is stuck closed, sealing the fuel line, not allowing any flow.

 

[Hammermechanicman]

Disconnect the outlet hose from the fuel pump. You can pressurise the tank about 1.5 -2 psi with your breath. Seal you mouth on the tank and Blow into the tank and you should get fuel out of the fuel pump outlet. If not something is blocking the fuel.

 

[Tiger Small Engine]

Disconnect the outlet hose from the fuel pump. You can pressurise the tank about 1.5 -2 psi with your breath. Seal you mouth on the tank and Blow into the tank and you should get fuel out of the fuel pump outlet. If not something is blocking the fuel.

First of all, running a twin 23 horsepower engine on one cylinder (for snow only) is kinda silly. I would address the issue.

Use an air compressor and blow back from fuel pump (line disconnected) to fuel tank, with gas cap off. Disconnect the two other lines from fuel pump and blow them out with air gun on air compressor. Crank engine with fuel line from fuel pump disconnected. You are looking for a strong steady spurts of fuel. Put some fuel in carburetor throat and see if it cranks.

 

[c1916]

Thanks for all the suggestions. I like the air compressor idea so I think I'll start there as I'm not entirely certain how I can seal my mouth on the tank to pressurize the line orally, but I'm game for anything at this point.

Regarding running the engine on one cylinder, my small engine guy has done work on this machine over the years and his opinion is that it is beyond repair. Also makes little sense to replace the engine, and I've already got a second riding mower so for me it's all about getting some value out of a declining proposition before disposing of the old hardware. I respect others may disagree with giving up on it.

 

[c1916]

Following up.

I connected an air compressor to the line from the pump through the filter and back to the tank (with the cap off). Completely clear. Saw evidence of fumes and spray blowing out the open gas cap.
I then sealed up the tank and siphoned (by mouth) gas from the tank toward the filter. Once it was in the filter, I stopped siphoning.

Reconnected all the lines (except the line to the carb which I expected to see gas pulsing from when I cranked). Cranked the engine and still no change. No additional gas entered the filter and no gas went through the pump.

I even bought another fuel pump figuring the one I had might have been faulty out of the box. But the new pump also failed to draw fuel into the pump itself.

To my mind, I had only one other option and that was to open up the vacuum. I released the bolts and finagled the hose out of the vacuum cover and, sure enough, there was a blockage in the vacuum hose. It looked like an inverted rubber cap (so instead of capping the outside of a hose, it sat inside the hose. Maybe it's part of the vacuum process, but it didn't seem right to me. I managed to get it out, so now the vacuum hose is also free flowing. I don't have gasket sealant in my garage so that's coming overnight so I can seal up the vacuum chamber. I did crank the engine with the cover off and the vacuum pumps do appear to be operating as I would expect them to. Maybe I'm off-base and the inverted rubber cap is a thing that needs to be in the line...and one of you can tell me what an idiot I am for removing it, but this has to be the last gasp. If I can't seal up the vacuum cover and hose with sealant and get fuel to flow...I think the old girl is destined for the dump.

 

[c1916]

Gasket sealant purchased. Put all the hoses together again and I've got gas spurting out of the new pump.

Cool, connect the last hose to the carb, nothing.

OK, I'm all in at this point, what are the odds of a blockage in the hose from the pump to the carb. Take all of the top unit off, release the final hose and ANOTHER inverted rubber cap in that hose.

I don't know where these all came from...maybe the last time I had my small engine guy do service he replaced hoses and they shipped with these inside? I can't think of any scenario where these caps could have "flowed" into the hoses from the fuel tank, they had to have been there when the lines were installed/replaced/repaired and I've never put a new set of hoses in myself. Over all of my attempts at repair, I found and removed three of these little buggers. Now, maybe one of you will come on here and educate me as to why these should be in my fuel line or what purpose they might have in the grand scheme, but once I removed the final one from the gates of the carb, the unit fired up like it was almost brand new.

Snowplow season saved...one more year from this Husqy.

Thanks for the suggestions and keeping me on track.

 

[Hammermechanicman]

Whomever installed the fuel pump didn't remove the protective shipping caps on the fuel pump and just shoved the hoses on over the caps.

 

[c1916]

Ah....I can see that now.

100% the the fuel filter I installed yesterday had no caps out of the box.

Can't say the same for the one I installed back in June just because of the fog of time, so I'll pay the idiot tax, but the problem arose ahead of June which was what led me to change the fuel pump in the summer.