Briggs 407777

[DennyIN]

I picked up a friends Craftsman 1000 mower that has been sitting for 3-4 years maybe without being used. She has a very small yard and the mower hasn't seen a lot of use over its lifetime. She is in her 80"s and wanted to have the mower running in case she needs it. She has had a mowing service care for her lawn for years. So I'm doing her a favor to service it and have it available, one of those pay for parts service calls. The engine is a Briggs and Stratton model 407777, Type 0121 ES, and code 00103YG. I replaced the dead battery with a 340 cca one, new air filter, plusg look like new etc. The tank was empty when I picked it up so I put alchol free fuel in it but it won't start on its own. It cranks great, and with just a very brief spray of carb cleaner in the carburetor it take right off, runs up good, idles good etc., but won't start on its own. I have removed the carburetor, disassembled it, and gave it the ultrasonic cleaning. I re-assembled it and same story, won't start on its own but just a very brief shot of carb cleaner in the intake and it takes right off, runs strong. I can hear and feel the fuel selenoid activating, and observed it working when the carb was disassembled and hooked up and tried. If I let it run and warm up it will usually start right up, but when I let it cool off it will just spin. I'm not sure where I should look next.

[RoyM]

I am thinking low compression on one or both cyliinders. Leaking head gaskets are not uncommon. Can you do a leakdown test?

[bgsengine]

simple things first - verify choke operation and make sure it is actually choking when the control is in choke position..

[Skywatcher]

Hi Denny

If memory serves me correctly, these machines have a separate choke control independent of the throttle control, usually located just above the throttle control. Check to see that the choke plate is actually closing when the choke knob is pulled out. Hope this points you in the right direction,

Sky

[KE4AVB]

That engine number is most likely the 407777-0121-E5.

Just something that has happen to me with these twin barrels related to the choke. I have repaired 3 of them on Kawasaki engines where the choke was heavily worn. One so much that it actual broke in two. Two of the three had to have bushings made and installed as the through hole for the shaft were heavily worn too.

Not saying it is the here but it is something to look for as the choke will not close properly.

I am wondering how a seldom used shaft gets so much when the throttle should have worn out first since it is constantly moving, I would have thought.

[DennyIN]

Thanks to all that replied. The engine is 407777-0121-E5, I took a picture and blew it up so I could better see it, thanks for the correct model number. I will take another look at the choke. The choke/throttle is all in one and I will verify the choke is activated and the cable is adjusted correctly. I have never had the leak down gauges, but plan on acquiring that possibly this weekend after investigating the choke. I was hoping this was something simple, but it may not be. I appreciate the support on this site. I lurk here and admire the professional responses the members post when a question is asked.

[38racing]

Hi Denny

If memory serves me correctly, these machines have a separate choke control independent of the throttle control, usually located just above the throttle control. Check to see that the choke plate is actually closing when the choke knob is pulled out. Hope this points you in the right direction,

Sky

LOL. I went all through the carb cleaner sprayer once this winter with a briggs twin on a rider with blower attachment. Next day it hit me. I hadn't pulled the separate choke .

[DennyIN]

If memory serves me correctly, these machines have a separate choke control independent of the throttle control, usually located just above the throttle control. Check to see that the choke plate is actually closing when the choke knob is pulled out. Hope this points you in the right direction,

Sky



Well how dumb can I be, pretty dumb. I just went out and looked, this does have a seperate choke. Pulled the choke out and it fires right up.

Thank you all for your help and sorry for wasting your time, unless you get a laugh out of this. I'll go back to lurking on here and try not to post anything more.

[Skywatcher]

Hi Denny

Glad we were able to help you on this one. With all vehicles being EFI since the 1990's, no one thinks about chokes any more. All the best,

Sky

[bgsengine]

Well how dumb can I be, pretty dumb. I just went out and looked, this does have a seperate choke. Pulled the choke out and it fires right up.
.

It's been known to happen.. even to the best of us..