Craftsman 19.5 only runs in choke position

[Kyle16284]

/forums/images/graemlins/confused.gifNo power. Starts fine in off/choke position as engine warms I have to slowly pull the choke out every few minutes to maintain enough power to cut grass. At times the mower will kill, and will not start back, the engine is not flooded. I had to change the coil once because there was no fire, but I know thats not my problem now. Any advice will be greatly appreciated.

Kyle

 

[arthurb]

Kyle16284

I had the same problem with a 8hp briggs&stratton that powers a craftsman 42" finishing mower. I looked in my owners manual on the fine tuning of my adjustment for the carburetor. I had to adjust the two screws for the idle speed and fuel mixture. I just followed the instructions and it works fine now. Also, check your spark plug, fuel filter and air cleaner. One of these three items might need replaced as well. It's funny, I never touched the adjustment on that carburetor before. How and why it went out of adjustment beats me. Vibration, or a low hanging bush/tree limb brushed up against the carburetor while I was mowing ??? All I know is that it works fine now. I hope this info helps you.

arthurb

 

[JimR]

You may need to pull the carb and clean it if you left the mower with gas in it over the winter. The gas of today's age really stinks. It gels up and leaves a mess behind. Always use Store-All during the off months. You may be lucky and only need an adjustment as mentioned above.

 

[GerardC]

How old is your machine?? Is it under warranty? If it is, let them fix it. If not, start with a basic tune-up and go from there. G

 

[jlbota]

If you are the mechanically inclined sort of person. Just pull the carb off and make note of where the throttle linkage a choke linkage are located. Take the bowl off the bottom of the carb you may see some sediment in the bowl. You then can remove the float by sliding the pin out that holds it. This will remove your float and the needle. Get some good carb cleaner and blow out every hole in the carb with the long skinny red tube that attaches to the carb clear nozzle it fits really good in those small holes. One note of caution when you do this (Wear safety glasses of some sort) The spray can come back at you and you don't want carb cleaner in your eyes /forums/images/graemlins/wink.gif Usually that is all that is wrong with these carbs unless they are completely worn out. But if its newer it probably just needs cleaned. Also check your filter as stated earlier. And if you can see down into your gas tank...(As some are mounted right under the hood)...Check to see if dirt is clogging the outlet from the tank...It only takes one good chunk to slow down the flow. If you suspect poor flow from the tank you can blow alittle compressed air through the line.....Again use safety glasses......

Make sure you have good clean fuel and a good clean air filter. If you are using a metal gas can...get rid of it and go get a nice plastic one as the metal ones rust and collect alot of junk in them.

Hope this helps..... /forums/images/graemlins/smile.gif

 

[BigDave]

(Wear safety glasses of some sort)

I will attest to this good advise. Gumout in the eyes burns like the dickens. /forums/images/graemlins/frown.gif

 

[RSKY]

Before you do anything else clean your air filter and check for wasp or other nests in the filter housing. Had a similar problem a few mowers back and all it took to fix it was cleaning the filter

 

[BRIGUY]

If you need to have the choke on to keep it running the fuel mix is way too lean. (Too much air not enough fuel) If the engine is starved for fuel using the choke will starve it for air correcting the air fuel ratio (aprox 14.7 to one).

These new emissions compliant units run lean as it is. to reduce hydocarbon emmisions. Unfortunately this is probably raising NOX.

It could be fouled gas in carb (Green mess smells like turpentine), plugged fuel filter, pinched fuel line, fuel pump problem, or Carb adjustment problem.

 

[robertm]

Before taking the carb off, you may try to get it running with the choke on and the air cleaner off. Then manually over-ride the governor to increase the engine speed (being careful not to over-do-it). Then choke the engine with your fingers, and "goose" it again with the governor to keep it running. Repeat this cycle several times. Many times, this "choking/revving" will suck a piece of grass or dirt out of one of the plugged venturi's preventing the engine from running. If it still does not work, open the high-speed needle adjustment a 1/4 turn (on the bottom of the fuel bowl). If it still des not help, the float/float valve could be sticking. In that case, remove the float bowl and clean the needle/seat, and reassemble. If the carb is not a bowl-type, then the diaphragm has a hole in it. Just some thought BEFORE you tear the carb apart and have to spend the money and time to rebuild it.

 

[gordonkearse]

I've experienced the same problem. I bought a carburetor rebuild kit but have refrained from installing it because my mower seems to run fine otherwise. It has done this for about three or four years. I adjusted the carburetor idle screw today and it doesn't seem to need anymore work. It is running fine with the choke off now. But I'll keep you posted otherwise. The idle set screw seemed a little weak. Perhaps it lost fine adjustment from rattling during operation. It is more likely it is a combination of a loose spring and dirty carb. My mower is 16 years old. I know no one has been into it. I always check the internet for similar problems. I get lots of good input. Thanks for this post.:thumbsup: