I had same problem and small engine shop recommended new cap. Maybe pressure issue with gas tank???

Several years ago my rider stared having fuel starvation issues. I tried cleaning the carb, replacing the spark plug, new fuel fiter, etc... none of it worked. I saw a suggestion that the fuel cap might be bad and causing venting issues. The quick fix was to drill a couple small (like 1/32) holes into the gas cap and give it a try. It worked, ran like a champ after that, I couldn't believe it.

Easiest way to explain it: Take a glass of water, put a straw in it, hold your finger over the top of the straw and remove the straw from the glass. Take your finger off the top of the straw, your finger is the vent .

To check if it's the cap not venting, simply remove or loosen it to see if it then starts and runs ok.

quote:

Originally posted by ridewv:
To check if it's the cap not venting, simply remove or loosen it to see if it then starts and runs ok.

I can do that.

Seriously, though- as has been pointed out in this thread, the issue is (at least) likely no-spark, since the engine should run for a couple of seconds after getting a shot of the starter fluid.

I found the manual for the mower, where it's probably been sitting since 2004, on a shelf in my garage. Incredible. Looks brand new.

Here's a link to the manual: Model # 917388541 Sears Craftsman gas walk-behind lawn mower

Parts: https://www.searspartsdirect.c...k-behind-mower-parts

Go ahead and check the spark plug gap since you messed with it . It can't hurt . Probably around .030 ".

I gotta find my gapper. The last plug I received (an OEM B&S plug) was properly gapped when I got it, so I ordered another B&S plug.

No spark would be the kill switch.

When you have the spark plug out, put a teaspoon or so of engine oil in the cylinder and pull start it a couple times.
This will help the rings seal if they have been washed down with starting fluid.
Have a fire extinguisher handy, or some hot dogs, incase you get a backfire and a flash fire.
Starting fluid, loose gas cap, bad fuel kinda thing.

This may help, if you decide to clean out the carburetor.



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quote:

Originally posted by Mars_Attacks:
No spark would be the kill switch.

This drove me nuts on the B&S engine on the wood chipper. I drained the gas, rebuilt the carb, replaced the magneto, and finally found out it was the kill switch.

quote:

Originally posted by Mars_Attacks:
No spark would be the kill switch.

Or the coil, no?

quote:

Originally posted by Mars_Attacks:
No spark would be the kill switch.

I forgot about that one. Happened about four years ago. I couldn't get our B&S mower in MI going and took it to the man: bad kill switch. First time I couldn't get a small engine going.

It was the frozen throttle cable.

Ordered a new one, installed it and it cranked on the first pull. Ran it 10 minutes, shut it down and restarted, and again, it cranked on the first pull.

Thanks to everyone for the help. It is very much appreciated.

And from now on, I'm running stabilized gas, preferably ethanol-free, and the tank gets run dry at the end of the season.

And THIS , ladies and gentlemen is why pulling the carburetor off and tearing it apart should be your last resort . It's strange that it cranked initially and then died , which made it appear to be a fuel issue though .

With it stuck wide open, being in clear flood, I guess it would be a fuel issue. Very hard to fix things over the internet, rather than actually being there. Stuck wide open it should have had spark and run on starting fluid. I think some luck was involved .

quote:

why pulling the carburetor off and tearing it apart should be your last resort

Anyone that thinks this doesn’t know these carbs.

You take the air cleaner off; two screws, maybe they’re bolts.

You clamp the fuel hose and remove it from the carb.

You remove the bolt holding the float bowl on. That bolt screws into the same spot the main jet is located.

You can optionally remove the main jet.

You can optionally take the pin out that holds the float and float needle in place.

Really all you do is hose everything down with carb cleaner at this point. Use the plastic straw to spray some through the main jet and the fuel inlet where the float needle is. Hit it gently with compressed air.

Put it back together. One bolt, one clamp, two screws, and fifteen minutes.

These aren’t motorcycle or outboard carbs with multiple fuel circuits and such.

Para, Murphy gas stations, usually near a Walmart, sell Ethanol Free gas. Many of them have the new pumps with a dedicated hose (BLUE handle) just for the Ethanol Free.

quote:

Originally posted by trapper189:

quote:

why pulling the carburetor off and tearing it apart should be your last resort

Anyone that thinks this doesn’t know these carbs.

You take the air cleaner off; two screws, maybe they’re bolts.

You clamp the fuel hose and remove it from the carb.

You remove the bolt holding the float bowl on. That bolt screws into the same spot the main jet is located.

You can optionally remove the main jet.

You can optionally take the pin out that holds the float and float needle in place.

Really all you do is hose everything down with carb cleaner at this point. Use the plastic straw to spray some through the main jet and the fuel inlet where the float needle is. Hit it gently with compressed air.

Put it back together. One bolt, one clamp, two screws, and fifteen minutes.

These aren’t motorcycle or outboard carbs with multiple fuel circuits and such.

I know a bit about carbs and I haven't had to remove one in years . They are not all the same . Float bowl versus diaphragm , etc. Tear a gasket or O-ring and your 15 minute job just got shot to hell . How many people here advised Para to remove the carb and take it apart ? Like most people here I assumed it was a fuel issue but no way I'm taking it apart until I'm sure . I'm going to stick with what works for me . You do you .

quote:

Originally posted by selogic:
It's strange that it cranked initially and then died , which made it appear to be a fuel issue though.

Yes, I've thought about this. The wire cable is in a plastic sheath and it's long been sticky. I've sprayed WD-40 or silicone spray lube down the tube many times to get it working but it hasn't moved smoothly for years.

Obviously, the throttle was in the off position, because I wouldn't have been able to shut off the mower the last time I used it if it wasn't.

So, pulling on the throttle handle manpowered the throttle open and I was able to start it, but after a few seconds of running, the vibration from the engine caused the cable to slip forward into the off position, and once in that position, it was finally frozen for good.

This is the only thing that makes sense of how it behaved, and since I knew I was negligent by using old fuel left in the tank over the winter, it did appear that it had to be a fuel issue.

Regarding pulling off the carburetor- to say I was hesitant to do so is quite the understatement. Three years ago, the cord for the starter pulley snapped and I had to replace it. Taking off the top cover and rewinding the pulley reel with a new cord (with help from youtube videos) was enough for me. I can just envision taking the mower to a repair place with a bag full of engine parts after I failed to fix it. "Here ya go, heh heh."

Anyway, it's been a damn good mower. It has to stay running as long as I stay running, because there's no way in Hell that I'm going to cut my yard with an electric lawnmower. That just ain't American.

quote:

Originally posted by Johnny 3eagles:
Para, Murphy gas stations, usually near a Walmart, sell Ethanol Free gas. Many of them have the new pumps with a dedicated hose (BLUE handle) just for the Ethanol Free.

Thank you. That's good to know.