Briggs 18 HP Hard to Start

[grumpyunk]

The fuel outlet inside the tank is getting clogged as the fuel falls into the tube leading to the fuel line. You may be able to remove the outlet(or not, depending on design) and clean up the schmuz, or will have to see if you can flush it out after removing the tank so you can position it to allow the stuff to get out with the flush.
tom

 

[bk10s]

Update: Removed the fenders and the tank. Tank was surprisingly clean (my wife was not too happy with the gas smell in the house from bringing the tank through to the basement!). Washed it out anyway. Tube and elbow clear. Maybe the fuel pump?

 

[grumpyunk]

I have had fuel lines that looked perfect fail to flow reasonably. The fuel over time had destroyed at least partially the inner surface and turned it into a maze. Fuel would not flow freely(gravity) through the line. You could check for gravity flow from the tank to the pump/filter, and then from there to the filter/pump, depending on the sequence. If all flows well, and the line from the pump to the carb inlet flows well, all that's left is the small volume of the inlet, and the pump. IOW, check it for flow or being able to blow through it a section at a time. Some pumps will allow slow flow via gravity if there is any height difference from tank outlet to the pump outlet as the little valves are not perfect and may allow seepage.
tom

 

[bk10s]

Going to put it back together with a new fuel line from tank to filter, and see where it's at.

 

[irineroger]

Briggs 350777 Replaced plugs, coils, adjusted valves. Have to turn it over for 20-30 seconds to get it to start. Once started runs fantastic. What am I missing? Some kind of fuel problem? Replaced fuel pump a couple of years ago.

 

[irineroger]

Briggs 350777 Replaced plugs, coils, adjusted valves. Have to turn it over for 20-30 seconds to get it to start. Once started runs fantastic. What am I missing? Some kind of fuel problem? Replaced fuel pump a couple of years ago.

I took out one plug and started it on one plug, let it run for a while then put that one back in and take the other one out, it spins like it should on one plug, after both are warmed up replace the other plug , it should start within one or two turns then. I had some help from up above!

 

[mechanizm]

there's an easy test. squirt some gas in the carb when cold and if it starts right up then you aren't getting enough gas. if this has a vacuum operated fuel pump, squirt the hoses where they connect to the pump with a little fuel / 2stroke oil mix. sometimes they suck air and even a little bit will keep it from pumping enough into your carb. It seals minor vacuum leaks. Most of y'all are over-thinking this problem.

Also, because of EPA the carbs run LEAN so any slight issue with the fuel pump will cause a hard-start problem. the reason it runs great after it starts is because it's creating more vacuum at the pump, overcoming the vacuum leak.

 

[Gord Baker]

Briggs 350777 Replaced plugs, coils, adjusted valves. Have to turn it over for 20-30 seconds to get it to start. Once started runs fantastic. What am I missing? Some kind of fuel problem? Replaced fuel pump a couple of years ago.

I don't know what a 350777 is but if it has an electric solenoid fuel shut off, be sure it is working. You should be able to hear it click when you turn ignition to ON. Check the multiwire connector(s) near the switch. Disconnect and clean them with Electronic cleaner and put back together tightly. Replace Fuel Filter and always strain your fuel.

 

[RestoGuy]

If you blew the line back in the tank you might have blown whatever junk that plugged the system right back in the tank...or...the tank needs a good cleaning. Drain and flush the tank...new filter and try again. Drain the fuel bowl and blow out main jet at the same time. You might be very close to a fix.

 

[nettles.w]

Briggs 350777 Replaced plugs, coils, adjusted valves. Have to turn it over for 20-30 seconds to get it to start. Once started runs fantastic. What am I missing? Some kind of fuel problem? Replaced fuel pump a couple of years ago.

I had the same problem for a few years. Finally, when I retired and got time to tinker with it, I ended up gutting the vacuum powered fuel pump and replacing it with a generic electric powered replacement. Problem solved. Starts first time, every time.