Wessex Flail Mower cutting out

[roys]

Got a wee problem with my tow behind Wessex Flail mower, it has a Briggs and Stratton 16HP ( I think) engine. It will start with the pull cord from cold perfectly with the choke remaining out for 5 seconds, it will then run perfectly on full revs while flailing for about 25 minutes and then it will cut out and die.

I then do the usual disengage the belt drive, put the Rev lever back to idle and pull the pull cord, it try's to catch, trying a bit harder as I quickly pull out and in the choke, die, pull pull cord again and the same just about catching, after doing this for 5 minutes it will catch and go to full revs again and stay there for 25 minutes again and so the same process will go on and on.

Thought it was the fuel filter as it didn't look too healthy, changed that, no difference.

Any ideas please?

[harrythecat178]

Fuel blockage somewhere. possibly fuel tap or filter in tank, or tank not venting properly

[roys]

Cheers cat178, so I have checked the jets I can see in the carb they look clean, took the cap of tank in case it was drawing a vacuum, none of these made any difference still struggled to start for 5 mins and then away it goes again as happy as can be, weird.......

[gooseflight]

Can't help only sympathise. I had exactly the same problem with a 14HP Briggs & Stratton Vanguard on a Logic mower.

 

I went right through the fuel system: stripped the card several times, new filter, new pump. Put it into a local small engine guy who declared it fixed but it wasn't.

 

I suspect it's valve related.

 

Can't be without the mower so swapped the B&S for a 14HP, electric start, Chinese unit.

[Tomf]

I have just had the same problem on my logic. I found this web page:

 

Route6x6.com - 6 and 8 wheel ATV how to's - Vanguard Carburetor Cleaning

 

I followed the steps in the pictures and left some mechanic in a bottle in the carb over night before refilling the tank and starting it up. While the tank was off I also drained it compleatly and let it dry out and cleaned it out as much as possible. It now runs the best it ever has since I've had it.

Hope it helps.

[dig-dug-dan]

Has the same problem with a honda engine, turned out to be the spark plug. It worked when cold, but as it got too hot, it failed. Sounds like the post above will also be worth a go

[roys]

Thanks gents, will give these a try.

[roys]

Dam you Briggs and Stratton, wasted so many hours on the engine this weekend,no stripped down the carb again, cleaned all the jets, changed fuel filter, cleaned out tank, still same fault.

So cleaned carb again, did away with pump, filter, tank, by rigging up a temporary tank gravity feeding into carb, same fault.

Next step, change the two spark plugs. It just sounds like fuel related but surely I have eliminated that now. So plug change it is.

Dam dam dam

[geoff]

Dam you Briggs and Stratton, wasted so many hours on the engine this weekend,no stripped down the carb again, cleaned all the jets, changed fuel filter, cleaned out tank, still same fault.

So cleaned carb again, did away with pump, filter, tank, by rigging up a temporary tank gravity feeding into carb, same fault.

Next step, change the two spark plugs. It just sounds like fuel related but surely I have eliminated that now. So plug change it is.

Dam dam dam

 

If the fuel system is all up to spec, suspect an ignition component breaking down under heat,it does happen, from plug cap right back to spark source.

[njm]

Dam you Briggs and Stratton, wasted so many hours on the engine this weekend,no stripped down the carb again, cleaned all the jets, changed fuel filter, cleaned out tank, still same fault.

So cleaned carb again, did away with pump, filter, tank, by rigging up a temporary tank gravity feeding into carb, same fault.

Next step, change the two spark plugs. It just sounds like fuel related but surely I have eliminated that now. So plug change it is.

Dam dam dam

 

Has it got a fuel stop solenoid on the bottom of the carb ?