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15.5 Briggs hard start when cold

#1

designr

designr

I have a craftsman lt1000 with a 15.5 Briggs engine it has no manual choke when i start it the first time that day it will take about five or six times to fire up. after that it fires up the first crank. I bought a fuel shut off to put inline because i was thinking that it may be loading up while it sits. If that does not help do you think i could install a manual choke? Any thoughts would really be appreciated thanks!!


#2

Arwing64

Arwing64

There can be a couple factors that could cause this issue. The valves are probably out of adjustment. To get to the valves, take off the valve cover (be sure to have some towels for oil spills). Loosen the two bolts. The valve gap for the intake is roughly .005" and the exhaust is .007". The tightness can be adjusted by turning a screw with a hex key or a torques bit. Once you confirmed that they are adjusted correctly, tighten down the two main bolts and bolt on the valve cover, making sure the valve cover gasket is still intact. Try starting the engine. If the engine still does not fire, try adjusting the carburetor mixing valve. If this still doesn't work, you can try your idea of hooking up a manual choke lever. I'm surprised it didn't have it already.

Let me know if you have any further questions. I will be happy to answer them.


#3

B

bertsmobile1

Before you start ripping the engine apart there are some simple things to check.
The first & most iimportant is to post your engine number and your mower number.
Then those who are in the trade & have all the information at their fingertips can give you the correct information for your machine.
Untill that what you will get will be just general guesswork which may or may not be what you need to know.

Next try some simple things, follow the throttle control cable down to the engine, check that the cable clamp at the end of the control cable is done up tight and the cable has not moved, preventing the throttle from fully engaging the choke.
The choke is as the air filter end of the carb & the throttle is nearest the engine.
When you see where the choke control rod is, move the throttle lever fully to the choke position and check that the choke control rod is fully on ( can't go any further).
If not loosen the cable clamp & move the throttle control wire till it dose, thighten the cable clamp then check the choke is fully off with the throttle in the run position.
And yes, unless this is a very new machine with auto choke, you do have one it is intergrated into the throttle control.

If the engine turns over very lumpy, then by all means check the valve lash however check around the rocker box for silicon sealer.
If you see some there then B &S did not fit a rocker box gasket so you will need to either buy one or get some gasket maker.
Ensure you remove all of the old silicon if it is there.

The external tap is a good idea, particularly if you fitted it between the tank & the fuel filter ( a contensious issue on this list ) and it will serve you well to turn the fuel off when you have finished mowing and let the engine starve but don't walk away & forget to turn the ignition off.


#4

T

Tinkerer200

"Next try some simple things, follow the throttle control cable down to the engine, check that the cable clamp at the end of the control cable is done up tight and the cable has not moved, preventing the throttle from fully engaging the choke."

From the above post is most likely, choke not fully closing. Valve adjustment does not have the symptoms described.

Walt Conner


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