Mower Idle Issues

Mowers, blowers & other important tools of the trade
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JollyGreen
Posts: 71
Joined: Sat May 12, 2018 8:05 am
Location: Charleston, SC
Grass Type: Zeon Zoysia
Lawn Size: 2000
Mower: California Trimmer Reel

Mower Idle Issues

Post by JollyGreen » Wed Apr 17, 2019 9:55 am

Last year was my first year using my California Trimmer reel mower. It has the Briggs and Stratton engine on it. It worked great all year, idled fine and before the end of the year I drained the gas for the winter. I did start it up mid January just to let it run for a little as I was changing the oil and backlapping / dialing in the reel. At that point, it worked great, no issues.

Yesterday was my first cut this year with it. Once I started the engine, it revs up and down quickly like it doesn't want to idle correctly. If I quickly close the choke it dies out. I played with the choke and had to tweak it to where it was 1/4 way or so open in order for it to idle correctly.

What could be causing this? I tried to move to ethanol free gas this year and when I did that the mower wouldn't run at all. It would die out in 15 seconds. I went back and put regular 87 in it and that's when I was able to get it working but also having to tweak the choke.

I am a little confused here as it was running fine and all the sudden am having issues. In my head ethanol free vs regular gas shouldn't make a difference but I am still having issues with the regular gas.

Desing
Posts: 9
Joined: Thu Apr 04, 2019 11:34 am
Location: Greenville, SC
Grass Type: Bermuda TifWay
Lawn Size: 7000
Mower: Toro GM1000, TB240

Re: Mower Idle Issues

Post by Desing » Wed Apr 17, 2019 10:17 am

I am not to familiar with that B&S engine, but this sounds like the engine is surging.

Did you drain the gas from the carb before winter? or just the tank?

Try draining the carburetor and cleaning it thoroughly with carb cleaner. Most of the times this happens from lack of fuel due to a dirty carb.

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jimbeckel
Posts: 263
Joined: Sun May 27, 2018 10:39 am
Location: Huntsville Al.
Grass Type: Zoysia/Bermuda
Lawn Size: 1/4 acre
Mower: GM1000, Allett B17

Re: Mower Idle Issues

Post by jimbeckel » Wed Apr 17, 2019 12:38 pm

The gas in the carb bowl should also be drained for winter storage, failure to do so results in gas being essentially stored in the base of the carb. You could remove the card and remove the bowl and spray out the carb with cleaner and also take a small pick or even bread twist tie a d clean out the jets. Reassemble and it should resolve the surging problem. YouTube videos are aweso.e if you want to watch someone perform the the procedure.

JollyGreen
Posts: 71
Joined: Sat May 12, 2018 8:05 am
Location: Charleston, SC
Grass Type: Zeon Zoysia
Lawn Size: 2000
Mower: California Trimmer Reel

Re: Mower Idle Issues

Post by JollyGreen » Wed Apr 17, 2019 12:53 pm

Good deal, thanks for the replies. I had a feeling it was something related to that. Just didn’t know where to start. The whole one type of gas working and the other not working really threw me off.

TonyC
Posts: 201
Joined: Thu May 17, 2018 9:52 am
Location: Atlanta
Grass Type: Zoysia - Zeon
Lawn Size: 7000sf
Mower: Jacobsen TC-22 & JD 220SL

Re: Mower Idle Issues

Post by TonyC » Wed Apr 17, 2019 1:06 pm

There are two carb styles on B&S. If you take a picture and share we can get you going down the right path.

It's likely that the low speed jet or emulsion tube has reduced fuel flow. When you use the choke, that is increasing the low pressure in the carb and sucking more gas through these parts so it runs. When you back off the choke then you have a fuel starvation occurring. Also, it's the combination of the low speed and high speed jets that supply the full fuel flow. If one is clogged then your air fuel ratio is wrong and will do the same.

Get on YouTube and find a video that steps you through it. Here is an overview that might help.

You could go the route of cleaning with SeaFoam overnight, that might be enough to break it up, but the tear-down and reassembly is not difficult, and can even be fun.

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