My mower starts up then revs for 2-3 seconds then stops. What should I look at? Last week it was kind of revving high then low...high then low. Now this week, starts but won't continue.
Craftsman 4.5 model #917387561 (if that means anything). I took the carb off and shot a liberal amount of carb cleaner in the carb and in the... excuse my ignorance... the hole where the carb attached to. I drained the gas, new gassed and changed oil. I put a new air filter on.
Same results.
Don't know what the float bowl is.
It has a fuel filter does it? Is it in the tank?
Inherited a Craftsman mower from the father-in-law a few years ago. The mower would crank fine but would only run for about 15 to 30 seconds. That is why he gave it to me. After repeated tries to run the mower. it would run for just 10 seconds or so. I finally determined that the gas cap was not allowing air to enter the gas tank, so there was no gravity feed of fuel. I loosened the cap a half turn and it ran like new, well it was practically new (2 years old). He was rather upset the problem was that simple. Give that a try before breaking down the carb. No cost involved and only a minute wasted.
To drain the float bowl remove the through bolt that holds it on..The bolt on the very bottom of the carb be careful to not overtighten the bolt as the carb os a weak cast metal.
May sound strange, but might take a look at the oil level. I remember working on a generator that had the same problem. After some head scratching with Dad, we checked the oil level, (very low) topped it off and it firerd right up and ran fine. Generator had a sensor that checked pressure and there simply wasn't enough oil. I know sounds really stupid and maybe your engine isn't set up this way, but what the hey?
Does it have one of those primer buttons on it? if so, that is your likepy culprit. the smallest crack on those will wreak havok on the way it runs/starts.