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I've had two shops try to fix my mower, which wouldn't start. They both put a 'float kit' in the carb. Finally got it started and running (sort of). When I started the engine at home, it seemed like the choke was staying closed and the engine would not rev up to the normal high RPMs. With my finger, I opened the choke by turning the butterfly lever at the top of the carb, and it ran better. I let it warm up, and it ran better, but I could tell it was still running very rich. I took the carb bowl off wanting to 'adjust' the float level as the bowl was totally full of fuel, but as y'all know, it's plastic and there's no adjustment to make. So I went back to the last shop, the guy gave me another kit. I removed the carb, checked to make sure the float doesn't have a hole in it or filled with gas; it's ok, installed the new rubber seat for the float needle valve, with the flat side down (that is, I could see the flat side of the seat looking down the hole) and a new needle valve. Put it back together, started it, still running very rich, flooding out. When I push the mower handle down toward the ground (raising the front wheels off the ground), in a short time the engine will finally rev up to normal RPMs. I let the wheels back down and start walking. In 25-30 feet, it begins to flood again. I repeat the handle down scene, it revs up in a short time, I start walking again for 25-30 feet, and flooding again. Any ideas. It is a Craftsman Easy Start mower with the Briggs 675 Series motor. Help?!

If you have an easy start, do you mean it has no primer bulb? If that is so then your problem may be that the auto-choke is not set properly. Please post your model numbers, so I can see which set-up you have.

I don't have the info you asked for as I am presently 100 miles from home. However, to answer your first question - no, it does not have the primer bulb. Also, if the choke is not set right, that would not be affected by the lowering or raising the handle, right? I have also set the choke to stay open.

Ok, I'll try to get you a procedure for adjusting the Auto-choke. Going to be out of town for the weekend (wedding) but will see what I can find ASAP. Will checking in when possible.

Rivets said:

Ok, I'll try to get you a procedure for adjusting the Auto-choke. Going to be out of town for the weekend (wedding) but will see what I can find ASAP. Will checking in when possible.

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Hello Rivets. Thanx for your interest in trying to help me with this problem. But I don't think the Auto-Choke is the problem. I think the float needle valve is not closing when the bowl is sufficiently full. I'm going to take the carb apart again to try and make sure that the valve isn't sticking open. I was just hoping that someone else had the same problem and could share info on how they remedied the problem. I'm going to try and put something to decrease the space the float needs to go up to shut the valve; put some foil or something under the base of the needle valve where it is connected to the float itself. In other words, make it close the valve sooner. It's worth a try. So in closing, don't worry about me and this problem. Go and enjoy yourself at the wedding! Have fun!

I understand what you are saying, but if the choke is not adjusted properly, you will get the same symptoms as a bad float setting. Another cause will be improperly installing the seat. If it is in upside down or not in far enough, it will do the same. Carefully look at the seat, you will see that it has a very slight taper. This taper goes in first. Also, you may not have installed it deep enough. After installation, check that the float sits level to the carb body, with the carb turned upside down and float pin installed. I also check my installations, before installing the float bowl, by blowing into the port where the fuel line is attached with the carb upside down. You should not be able to blow the needle off the seat when blowing with your mouth. I will continue to look for the choke adjustment I was talking about. Just had a thought, do you have a small spring attached to the choke/air vane arm, just above the carb? If it is not there (seen many missing) it will contribute to your problem.

In the old days of auto carbs...specs called out a stroke set by the fully open and closed float needle. Set by bending tangs. Also used to check for punctured float by shaking and listening. Have had debris jam open a float valve. Worn valve can have wear ring at seat interface. I realize these little carbs may be different. Just ideas.

I would make certain the float is closing the needle valve. Make sure the float is horizontal. It is alright if it is a little higher than horizontal but if it is lower than horizontal the needle valve will not seat. Bend the tab under the needle valve to adjust.

Rivets said:

I understand what you are saying, but if the choke is not adjusted properly, you will get the same symptoms as a bad float setting. Another cause will be improperly installing the seat. If it is in upside down or not in far enough, it will do the same. Carefully look at the seat, you will see that it has a very slight taper. This taper goes in first. Also, you may not have installed it deep enough. After installation, check that the float sits level to the carb body, with the carb turned upside down and float pin installed. I also check my installations, before installing the float bowl, by blowing into the port where the fuel line is attached with the carb upside down. You should not be able to blow the needle off the seat when blowing with your mouth. I will continue to look for the choke adjustment I was talking about. Just had a thought, do you have a small spring attached to the choke/air vane arm, just above the carb? If it is not there (seen many missing) it will contribute to your problem.

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Hi Rivets. Well guess what? I took the new airfilter off, closed the choke, and it fired right up and ran with good RPMs! Go figure. And yes, there is a spring on top of the carb. Anyway, I'm going to just go ahead and use it without the airfilter installed, but just the cover.

motoman said:

In the old days of auto carbs...specs called out a stroke set by the fully open and closed float needle. Set by bending tangs. Also used to check for punctured float by shaking and listening. Have had debris jam open a float valve. Worn valve can have wear ring at seat interface. I realize these little carbs may be different. Just ideas.

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Hello Motoman. The float tang is plastic and the setup cannot be adjusted. I took the airfilter off and the engine now runs fine. It is a new airfilter. Thanx for the reply.

Just so we know what you have, post the engine's model numbers.

Thanks

I have seen cars do the same thing. Wont run worth a darn unless the air filter was removed. So, someone with good knowledge please riddle us what the problem is for future reference please.

hntrsr said:

I would make certain the float is closing the needle valve. Make sure the float is horizontal. It is alright if it is a little higher than horizontal but if it is lower than horizontal the needle valve will not seat. Bend the tab under the needle valve to adjust.

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Hello Hntrsr. As I've posted above, on these newer models, the float level cannot be adjusted by bending a tang like in the old days. The setup is plastic and 'set' as it is. I have figured out that the float evidently is not the problem as I originally thought. It is working as it should. I finally decided to take the airfilter off, look down the carb throat and make sure all was well. I then tried successfully to start the engine, and it ran normally, as it should; but with the new airfilter removed. I put the airfilter cover back on and mowed my lawn without problems. Even though I know it is certainly not the best thing to do, I'm going to run it like that from now on for the rest of the summer and then see if I can get it worked out this fall.
For all following this thread: Briggs/Stratton motor Serial number is: 0801175991785 Build date: 01/08

We need the model and type number as well, look around the valve cover, it should be etched or stamped into the metal.

Try installing the air filter, but just lightly tighten the screw. Running with no filter will greatly shorten the life of your engine.

Fish said:

We need the model and type number as well, look around the valve cover, it should be etched or stamped into the metal.

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Here are some numbers stamped on a black metal piece on the front of the engine: 126L02-1082-F1 08011759
It is a Briggs & Stratton 675 Series. Thanx!

Rivets said:

Try installing the air filter, but just lightly tighten the screw. Running with no filter will greatly shorten the life of your engine.

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Rivets, you 'da MAN!! As I had mentioned in a previous post, I know that running an engine without the airfilter is not the best (right) way to go, but if that's what it takes for the engine to run, I was going to do it. However, I decided to apply your suggestion of not tightening the screw on the airfilter cover so much. Voila! It runs like it is supposed to. Good on 'ya, Rivets! Evidently, the air filter was being pressed into the choke butterfly and wouldn't allow it to open completely. Of course, when I'd remove the airfilter, everything looked fine. Anyway, to all the rest of us 'shade tree mechanics' out there, the problem is solved. The first time I lightly tightened the screw it was too loose and the filter cover popped open after about 10 mins of running the mower while mowing the lawn. So I tightened it a little more, but paid close attention to when the screw made contact with the cover, then went about a half turn to a full turn more and it stayed in place. Thanx to all of you for your posts and suggestions and input. I wanted to let you all know, what solved the problem, as well as the cause; just in case someone else out there is having the same issue. Take care ya'll. Volklskier

Sometimes I get lucky, sometimes the simplest things are hard to find. Glad to see it worked.