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2019/08/10 18:18:08
John Fitz

Briggs and Stratton EFI 11.5 hp Powerbuilt

Hi 
 
I am having a problem with my brush cutter. The machine is a Swisher Predator, 24 inch Rugged Cut Brushhog. It is slightly over a year old and was bought on Amazon. The engine is a Briggs and Stratton EFI 11.5 hp Powerbuilt. Pull start only. There are approximately 20 hours on the machine. It “seems” in good shape, and the previous owner said he did not have any problems. I bought it with about 10 hours of use. It has not seen any hard usage, though I did tangle once with a hidden metal fence post and the engine cut out, but it kept working after.
 
The issue is that the machine runs great for about ten minutes at full throttle (20 minutes if it is set to a lower throttle). After that, it will stall out if under any minimal load of light brush; and after that, it stalls even if not under load or the blade is engaged every five minutes or so. It always starts right up afterwards. The stalling occurs more frequently the more the machine runs.
 
As suggested by support at Briggs and Stratton, I replaced the fuel pump, but the same issues occurred. I have tried loosening the gas cap to see if there is a vacuum issue (though I have not replaced the cap). That also did not work. I drained the old gas and put in fresh, and I changed the oil and replaced the two belts. The fuel filter seems fine. 
 
Right now, I am stymied and hoping that maybe it is still under warranty. I have never worked with an EFI small engine, and I wonder if there is a fuel injection issue, but that is just speculation based on my own ignorance. I am hoping that you might have a couple of other options that are worth trying before I bring it to a shop.
 
Any thoughts would be appreciated. 
 
Thank you for your time,
 
John Fitzsimmons
[email protected]
978-793-1553
12 comments Leave a comment
Roy
Can you give us the model and type number from the engine? You could have vapOr lock due to the routing of the fuel line. The ignition may also be heat soaked.
2019/08/10 20:16:04
John Fitz
Thanks for the quick reply. I will get the model number this morning.
2019/08/11 07:34:32
John Fitz
Model 21R806  0047  F1 170418ZD
 
The Engine is a 344 CC 11.5
 
Thanks: 
 
2019/08/11 09:20:22
Roy
That is a conventional carburetor, not EFI. Drop the bowl and check for debris.
2019/08/11 11:58:45
AVB
Roy
That is a conventional carburetor, not EFI. Drop the bowl and check for debris.

Didn't think Briggs has gotten into EFI on this smaller of engine. I did know Robin/Subaru tried it and failed.
 
Does sounds like an ignition problem of the ignition coil or spark plug; although, checking and cleaning the carburetor is a good idea. Also check the fuel line for a collapsing liner. I have seen a few EPA lines where this has happen.
 
As Roy said it is possible to have a fuel line vapor lock especially if using E10 or above fuel. Boiling point is much lower than non alcohol fuel.
2019/08/11 12:38:48
John Fitz
Don't know how I got it in my head it was an EFI. The carb has some sort of solenoid thing on the bottom. What is that? I'll clean the carb, but I am not sure why a messy carb would cause the hot stalling. I have been using 87 gas. I'll change the plug too. If it is the coil, I'll bring it to a shop. I have been using 87 gas. Not sure how to approach that problem. Many thanks for the help! I'll let you know if it gets figured out.
 
2019/08/11 18:03:48
AVB
Be carefully cleaning the carburetor for if the main jet o-ring is loose you can lose the jet easily and it nearly impossible to find. I know there is several somewhere in my shop. Also being a Nikki the fuel bowl gasket can be easily damage if you don't back exactly in its place.
 
It is an after fire solenoid used to fuel off to the main jet to help prevent the loud boom that occurs in the hot muffler as raw enters the exhaust when the ignition system shuts down.
 
They usually only fail a couple ways. Either they don't open the fuel supply to the main upon starting or they stick open allowing the raw fuel to enter the muffler then you heard what some call a backfire sound. Both is usually fuel gumming them up. but other damage can cause the same thing such as rust or a melted internal wiring. This year I have had three in a row to have the rubber tip to come off causing problems. The engines would start but would not stay running because the rubber tip getting up over the main jet and block the fuel flow.
 
Now they due short out but that is usually rare and is self contained.
2019/08/11 18:26:31
John Fitz
Would you recommend swapping it out? The ignition coil is only thirty bucks. Is that worth swapping? Thanks for your input.
 
I must say that the feedback I get here is far superior to the suggestions from Briggs or Swisher support.
2019/08/11 18:31:07
AVB
Would you recommend swapping it out? The ignition coil is only thirty bucks. Is that worth swapping?

 
It wouldn't hurt to try. I have seen pretty strange electronic controlled coil failures over the years.
 
I must say that the feedback I get here is far superior to the suggestions from Briggs or Swisher support.

 
At least you getting a response from Briggs. They haven't replied to any my emails through the Power Portal this year. I feel they are just ignoring me. Even Power Distributors takes my question but never call me back. Not a good way to make a stand alone dealer (repair shop owner) feel good about their support.
 
Good thing I have been working on equipment for 40+ yrs and have found places for support with my more difficult problems.
2019/08/11 18:50:55
John Fitz
Yes: This has been a godsend to find. Next, I'll have to figure how to get my old Bunton mower moving again:)
 
Thanks again
 
2019/08/11 18:56:17
John Fitz
Would anyone recommend wrapping the fuel lines with a heat shield? I've seen that done on older sports cars.
2019/08/19 10:04:01
AVB
Balladmaker
Would anyone recommend wrapping the fuel lines with a heat shield? I've seen that done on older sports cars.

I have seen it done on some JD mowers. And cases of fuel boiling in fuel lines it can help especially on gravity fed fuel system where this fuel vaporization causes a vapor lock in the fuel lines.
2019/08/19 12:06:47

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