[Kennydm7]

D100 Series D155 with 24HP Briggs & Stratton surges. Changed fuel, air/fuel filter, plugs and gas cap. It starts right up but when I pull it out of choke it surges, I did find a "sweet spot" where it's just sightly choked - the rpm's increase and it runs smoothly without surging (for a while).
Any suggestions greatly appreciated.
Thanks
Kennydm7

 

[MARK (LI)]

Hi Kennydm7

Possibly an air leak on the manifold where the carb bolts on...use a hand held propane torch with NO FLAME and aim it at the base of the carb and shoot a little bit of the propane while the engine is running and surging...see if this stops it...if not, you probably have some debris in the carb somewhere...take off carb and clean it out thoroughly...not just shooting a can of carb cleaner at it...get yourself this kit for getting into all the jets and orifices

 

[Alien5044]

Welcome to MTF!

Mark's suggestions are, as usual, spot on. Surging is classic clogged jet symptom particularly if you eliminate a leaking gasket as an issue. You further diagnosed it by finding a bit of choke resolves the surging. Some folks will try to adjust the fuel/air screw if so equipped, but that is just a band aid and masks the problem, a restricted jet in the carb.

Lots of posts on surging if you use the search function. Read through them for some good insights.

Clean carbs don't surge. Get a carb gasket set, a couple of cans of carb cleaner, a bit of nylon or plastic to poke around and clear the internal carb passages, and you will likely fix the problem.

 

[Kennydm7]

Hi Kennydm7 View attachment 2556438
Possibly an air leak on the manifold where the carb bolts on...use a hand held propane torch with NO FLAME and aim it at the base of the carb and shoot a little bit of the propane while the engine is running and surging...see if this stops it...if not, you probably have some debris in the carb somewhere...take off carb and clean it out thoroughly...not just shooting a can of carb cleaner at it...get yourself this kit for getting into all the jets and orifices
View attachment 2556439

Great idea, I'll check it out. Thanks!

 

[Kennydm7]

Welcome to MTF!

Mark's suggestions are, as usual, spot on. Surging is classic clogged jet symptom particularly if you eliminate a leaking gasket as an issue. You further diagnosed it by finding a bit of choke resolves the surging. Some folks will try to adjust the fuel/air screw if so equipped, but that is just a band aid and masks the problem, a restricted jet in the carb.

Lots of posts on surging if you use the search function. Read through them for some good insights.

Clean carbs don't surge. Get a carb gasket set, a couple of cans of carb cleaner, a bit of nylon or plastic to poke around and clear the internal carb passages, and you will likely fix the problem.

Thanks so much for the helpful info.

 

[Frogmore]

Before you go to all that trouble, go buy some SeaFoam. It might save you having to take off the carb. Once you do get it working, put stabilizer in your fuel. I use Sta-bil 360 in mine every time I pick up gas at the station. Some people swear by ethanol free gas. I would use it but I would have to travel about 30 miles to find it.

 

[Kennydm7]

Before you go to all that trouble, go buy some SeaFoam. It might save you having to take off the carb. Once you do get it working, put stabilizer in your fuel. I use Sta-bil 360 in mine every time I pick up gas at the station. Some people swear by ethanol free gas. I would use it but I would have to travel about 30 miles to find it.

Thanks, I'll check it out.

 

[Kennydm7]

Welcome to MTF!

Mark's suggestions are, as usual, spot on. Surging is classic clogged jet symptom particularly if you eliminate a leaking gasket as an issue. You further diagnosed it by finding a bit of choke resolves the surging. Some folks will try to adjust the fuel/air screw if so equipped, but that is just a band aid and masks the problem, a restricted jet in the carb.

Lots of posts on surging if you use the search function. Read through them for some good insights.

Clean carbs don't surge. Get a carb gasket set, a couple of cans of carb cleaner, a bit of nylon or plastic to poke around and clear the internal carb passages, and you will likely fix the problem.

Thanks, great advice!