Hello,
Been trying to get my mower going and well not going very well

here is the issue

hard starting all the time
will run for 15min then die starts back up, then dies...this is not happen all the time
sometime it will start for a 2min then dies
also when it runs it will die when pto is engauged

Mower is a simplicity lth 16hp briggs vanguard 89 vintage

briggs #303777-0122-01 8905251

all new belts
new fuel
new fuel fiter
new oil
carb taking apart cleaned
new alt, and regulator, battery new,
adjusted valves
compression test cy1 70 cy2 75 cold
new ignition
new pto switch
new main engine harness

any help would be appreciated

Thanks Erik

 

Does it dies like it's starving for fuel? If so, try loosening the gas cap and see if it will run longer. Could be a plugged vent in the cap.

 

yup tried that already no go, not sure when it dies it just like some turned it off

thanks
erik

 

Does it run fine when it does run? From full speed to idle, it runs perfectly?

 

when I get it to run it will first only run and low throttle and after about 10min if it stays running I then can go full throttle until I put a load on it when I engage the pto, doesn't seem like it has enough power to run

all pulley on deck move free

seem like I have several issue, the starting issue and the dies under load issue

when I first got the tractor it would die when it was hot, but then it would restart but the pto would not work after

thanks
erik

 

Cheese,
Doesn't it seem the compression is pretty low? In the first message it says 70psi. From what I've found anything around here or below 80psi is pretty rough to keep running. Just wanted to throw it out there.

 

With compression release mechanisms, it's hard to get a real compression reading from many small engines.

 

update,

ran all new fuel lines, added sea foam to tank

still having starting issues, and keeping running, after about 10 min with pto on it will die, and then seem to run rough and if I put any load it will also die

it does have spark when it dies and will start right back up, but runs like crap

thanks
erik

 

update update
well got some used parts, tried 2 used coils and put a used carb on, cleaned carb before I put on, well it starts right up seem to run ok at idle, at full throttle and trying to engaged the deck, at first runs very slow no power, then dies, and if I turn of pto, mower does not run good, no power slow rpm even at full throttle

did have spark testers on both cyl. and have plenty and did not go away when it died, also tried with kill wire off and it still died

has new pump
new plugs
all new fuel line, sea foam in the tank
adjusted valves

maybe headgaskets??

any idea would be big help

loosing my mind here

thanks erik

 

Not headgaskets. I think you have a fuel related problem. Something to do with the carburetor(s). Apply partial choke and see if that helps it run better. Also make sure the pump is actually pumping fuel strong even though it's a new pump. That is one really good engine, it's worth fixing.

 

thanks, well took carb back off and clean out all hole with a needle, put carb back on, took awhile to start.. but ran ok with choke close with choke open dies even just a little open dies, will run at half throttle ok, at full throttle it run ok at first then start to hunt and then will die??

I have fuel coming out of pump, not sure if there is a enough, new pump is plastic old pump metal?, also have clear plastic fuel filter and there is fuel in it when it runs.

thanks
erik

 

I've had those carbs give me fits before. I think something is clogged in it. You may need to remove the jets and the smaller jets behind them.

 

cheese,

Thanks for the input, took carb off and took entire carb apart soak it in cleaner for 12 hours, then took needle and poked all holes in carb, the blew all holes with compress air.

Put carb back on, and well same problem, though rpm is a lot high then before but with any load and high rpm it just dies, kill wire is disconnected from coils

Thanks Erik

 

Applying choke doesn't help? I still think you have carb trouble.

 

New carb?


runs for a little while with choke close with choke open dies even just a little open dies?

erik

 

Every time you remove and clean the carb, you end up with a different result. If it was running the same every time, I'd say maybe it's a vacuum leak at a gasket or some other problem, but it's changing. Check the intake gaskets, fuel supply volume, valve adjustments, and everything else one more time to be sure to eliminate them and if all still points to the carb, I'd say have a pro drop it in commercial carb cleaning acid at an automotive machine shop or get another.