Briggs and Stratton 725EXI wishing it was a Honda

[8thborn]

Don't get me wrong folks, I have a 20 year old Snapper walk behind with a Briggs and Stratton which still runs great, never an issue. Matter of fact, I pulled it out of retirement when my one season old Husqvarna crapped out. As most, I initially thought winter, old ethenal gas, plugged carburetor. So I cleaned the carb 3 times before buying an ultrasonic cleaner at Harbor freight and really cleaned it a 4th time with no luck. Although I had spark, I replaced the spark plug (checked the gap). I also verified the magneto gap. Yeah, it has compression. Finally...I replaced the carburetor with a new one. Guess what, still no cranky. I am thinking of either putting a Honda engine on it, or the one out of my '68 Bug. At least I can work on that.

Seriously though, any ideas would greatly be appreciated as this thing has got me stumped.

 

[primerbulb120]

If you give it a quick shot of starting fluid in the carb throat, will it start and then stall?

 

[8thborn]

It will half heartedly "hit a lick". It acts like it still is not getting fuel, but a new carb?

 

[primerbulb120]

Did you drain the gas tank and clean it with fresh fuel? Another thing to check would be the autochoke mechanism. Take off the engine shroud and make sure there aren't any leaves, sticks or rodent nests keeping the mechanism from moving. The choke valve in the carb should be all the way closed when the engine is cold, and should open when the engine starts.

One more thing: Double check to make sure you have the throttle/governor linkage hooked up correctly. No disconnected springs, no debris in the linkage and make sure the linkage is in the right hole on the carb (if this is a carb that has multiple holes on the throttle valve.)

The throttle should be all the way open when the engine is cold, and it should be about 1/4 open when the engine is running.

 

[8thborn]

All of the above has been checked and is ok. Clean tank, fresh erhenal free fuel, choke linkage good, springs intact, linkage connection correct. The thing has an auto throttle so I can'tt do much with it.

 

[8thborn]

Oh yeah, there are only two linkage holes, throttle and choke, and they are different sizes.

 

[8thborn]

I am replacing the armature/magneto because it is cheap to do, and will rule out a weak or intermittent spark.

 

[primerbulb120]

Good idea. :thumbsup:

 

[8thborn]

Well, I replaced the magneto and still no luck. That's a new spark plug, new carburetor, new magneto, all on a new motor with about 5 hours of run time. What's left?