# Intermittent flooding/hyd lock



## andyvh1959 (Jul 1, 2015)

I have a 15.5 B&S Intek single in my old Ingersoll lawn tractor. This single has the fuel shutoff solenoid on the carb bowl. I also have a fuel shutoff valve in the fuel line. A few times in the past year I'll be running the tractor and then shut it down to move stuff while mowing. Go back to start it and "THUNK", no turnover. So I try the pull-start backup and nothing, can't turn it over. Pull the spark plug and pull it over and a spray of gas shoots out. 

Plug back in and it starts right up. Might run fine for days, weeks, then again repeat. 

For years this thing always started fine on the electric starter. Past few years, nope. New battery, nope. New starter solenoid, nope. New ignition switch, nope. Last year I found the ground cable was busted inside the sheathing. New cable and good for a bit, now nope. But I can always start it using the pull start. Now with the ignition switch all I hear is the solenoid clicking but no cranking. I may try a jumper cable from the battery to the starter positive post just to see if it cranks over. Puzzling.


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## Bob Driver (Nov 1, 2017)

_"Pull the spark plug and pull it over and a spray of gas shoots out"
_
Your float needle seat is leaking. Some Intek carbs ran a little tiny red o-ring with a metal-tipped needle (part #398188). Very easy to lose if you've had the carb apart, or blow shop air through the fuel inlet without the float needle in place.









Others, ran a brass seat with a rubber-tipped needle (part # 799177). You use a self-tapping machine screw with a nut/flat washer to pull the old seat out. I use a 1/4" drive, 10mm socket, over the top of the float tower as a kind of puller. Seat the self-tapping machine screw as far as possible into the brass and tighten the nut against the top of the socket/washer to extract the seat. Heat the tower slightly and the new seat usually taps right back in place.









Briggs actually sells a kit to change brass float seats. Works to pull the brass float seats on Kohler carbs also.....


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## andyvh1959 (Jul 1, 2015)

Thanks Bob. I suspected it to be a flooding issue caused by the float needle. But i sold the old Ingersoll lawn tractor before I needed to go into it. Good to know in general about the carbs on the B&S.


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## Bob Driver (Nov 1, 2017)

Yep.... Brass seat = rubber-tipped needle. O-ring seat = steel needle

Kohler is the one that bites you in the butt on their single-cylinder Command Pro Carbs. They don't sell the seat separately, only in a "kit"..... Kohler Part # 1252104S and it's usually over $30.

You can get a new carb, made by the same fine folks that shipped us the virus, for under $20


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## andyvh1959 (Jul 1, 2015)

On the subject of new carbs, are the Kohler, Kawasaki, Briggs, etc OHV engines power output determined/adjusted by the carb sizing like the older flat head engines? I'd always heard a Tecumseh Snow King 8hp engine could be upgraded to a 10hp engine by just installing the carb and intake from a 10hp engine.

To make a 25% power increase just by changing the intake and carb seems very unlikely without cam changes, valve size/lift changes, etc. Or, are the older flat head engines designed as higher output and then "downgraded" power wise to suit various market needs. That way the same engine block can suit an 8hp snowblower, and also be priced up significantly for a 10hp snowblower with very inexpensive changes by the engine builder. Economy of manufacturing.

"Shipped us the virus" means from now on I always consider the product source for my purchases, and I WILL pay more happily if it is a US product.


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## Bob Driver (Nov 1, 2017)

On their bigger FH series V-twin engines they run a 2-barrel Nikki carb, Kawasaki manipulates their horsepower by the degree the carb butterflies open
(/ versus - )

Got a 19HP FH601V and you want to jack it up to a 25HP FH721V.... Trim the aluminum butterfly stop on the carb body, or change the brass butterfly rod in the carb (different stop angle) and add the oil cooler kit.

From the FH601V(19HP) to the FH721V(25HP), they're all 675cc engines and run the 621266 Nikki carb, the difference is in the angle of the stop on the brass rod and how much it allows the butterflies open.

FH601V 675cc 19hp
FH641V 675cc 21hp
FH661V 675cc 22hp
FH680V 675cc 23hp
FH721V 675cc 25hp

SHHHH...... Kawasaki doesn't want you to know that


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## andyvh1959 (Jul 1, 2015)

Aha, just what I suspected. The engines are designed as higher horsepower, and then powered down using the intake and carbs. Makes sense though from a manufacturing point of view, less specialized casting, machining, parts, assembly controls, quality issues when most of the product is built the same way. Then "tailor" the application to the market with the most easily changed accessory components, those being the intake and exhaust side of the basic engine. 

I bet Kawasaki isn't the only engine manufacturer that does this. To be competitive cost wise all the engine companies probably follow the same format. Especially the likes of B&S being the biggest builder of small engines world wide (for now). Honda may be the exception, though I doubt it. So, if I buy a specific lawn tractor, mower, etc and feel a bit more power is beneficial I can go the old "hot rod" route and reasonably increase the power with carb/intake/exhaust tuning.


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## Bob Driver (Nov 1, 2017)

On the FH series Kawasaki 601 and up..... It takes a die grinder, buy the different butterfly rod, or swap carbs over from the higher HP engine and it will have the different angle on the control rod

Small Engine Warehouse...
FH680V-S28 675cc 23HP 1" shaft $1,929
FH721V-S13 675cc 25HP 1" shaft $2,019


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