Intek 18 hp OHV- #31E777 0443 E1. Loud popping at higher RPM, under load, or hitting bumps(roots, etc.) Video under 1st Reply. Thanks for any input.

[Mower King]

Fixed everything and still made no difference. Start doing same thing while mowing today. Will go 3400 RPM sitting in neutral with blades not spinning. Maximum 2500 or so moving with blades engaged. Any more and POW, POW, POW, POW with black puffs of smoke out exhaust. One odd thing was while adjusting carb unscrewed the idle screw all the way and wouldn't drop below 1900 RPM no matter where I set the mixture. Driving on hill with left side down and non-stop popping out exhaust with black puffs of smoke. No matter what I can not run wide open while cutting and moving. Just frustrating. I'm about to give up and just buy a new motor. This just sucks. Tons of work, time, and parts with no effective change. Also while adjusting the mixture could literally take screw clean out of the carb and it never effected how it was running. Screwing mixture inward would bog down at some point. But not when backing it out.

I guess you could, take it to a shop that does this kind of thing for a living.....just say'in

 

[Klyonh]

And it would cost more than a new engine would cost. No thank you. Thanks, but in all honesty on some level I've been enjoying learning about my new used mower. I've taken cars down to the frame and back, rebuilt 4 bangers to V8's to putting an Evaporator in my 2013 Chevy Volt(toughest job I have ever tackled). But I've never really worked on small engines other than a mini-bike and a lawn boy that wouldn't die, both of which over 30 years ago.

 

[lefty2cox]

Before you give up on her, did you check the flywheel key? I've been burnt by it before. I've seen partially sheared keys cause a multitude of problems, some logical, some not so much. Now I always check it first.

 

[cpurvis]

In one post, you mentioned puffs of black smoke. That is indicative of a carburetor problem.

Why did you replace the carburetor and where did you get it? Did you save the OEM carburetor? I would be tempted to rebuild it or have someone rebuild it.

 

[Klyonh]

Before you give up on her, did you check the flywheel key? I've been burnt by it before. I've seen partially sheared keys cause a multitude of problems, some logical, some not so much. Now I always check it first.

Just replaced it when I replaced the breather reed and tube.

 

[Klyonh]

In one post, you mentioned puffs of black smoke. That is indicative of a carburetor problem.

Why did you replace the carburetor and where did you get it? Did you save the OEM carburetor? I would be tempted to rebuild it or have someone rebuild it.

I am thinking you are right. I am going to buy another carb. This one just doesn't seem right. 1/2 the time when I buy something new it is bad, so I am going to buy another carb. Already got rid of the original, stupidly.

 

[lefty2cox]

The video sounds like it's being choked, or at least similar to that sound. I have the same engine. This is the one with the push linkage that engages the choke above full throttle, not a separate choke cable? Is that choke return spring on the carb intact? Any way you can run it with the airbox elbow off briefly to see what the fuel system is up to when this occurs?

 

[slomo]

I agree with the others above. Sounds like carb issues. Take air filter off and watch the carb linkage. Take your finger and adjust to 3400rpm. You said without the blades on it's fine. Under load is where you have the issue. So fuel delivery issue, fuel pump if you have one, dirty carb, stale fuel, water in the gas or faulty new carb. Was this an OEM carb or Chinese Ebay? Do you have strong blue spark? If your coil is weak, might run ok with no load. Then it might dog out under load. Black smoke is unburned or excess fuel.

slomo