Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Mower engine high idle and stalling


aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

09-03-16, 08:33 PM   #1  
Mower engine high idle and stalling

Hi,

I have a Bunton 48" walk behind mower with an Onan E125V (12.5 HP) motor that will start, but seems to idle very high with the choke on. If I move the throttle cable out of the choke position it starts to die out, unless I move it back to the choke position.

There was some old fuel that I recently siphoned out, replaced with new fuel and fuel and air filters. Previously it would start fine, but then stall either in the middle of mowing or soon after being started - either way it wouldn't start again for a while. Now I can start multiple times in succession, but with the above noted problems.

I checked position of the throttle plate and cable, seems to be operating OK and in the correct position, so I'm not sure if I have a governor issue or what at this point. Thanks for any help!

 
Sponsored Links
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

09-03-16, 08:36 PM   #2  
You have a restriction in the carburetor from old fuel and the throttle plate is probably stuck for the same reason. A carb cleaning is in order.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
Pilot Dane's Avatar
Group Moderator

Join Date: Mar 2003
Posts: 16,680
NC

09-04-16, 04:13 AM   #3  
And when Cheese says carb cleaning he probably means that it needs to be removed from the engine. Disassembled, soaked and cleaned to make sure all the internal passages jets and orifices are clear. Simply getting a can of carb cleaner and spraying the outside or down the throat of the carb will not do it.

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

09-04-16, 10:10 AM   #4  
Thanks, I started looking for a carb repair kit last night before I go taking it apart, but couldn't find anything yet. I don't own an ultrasonic cleaner, guess will have to look for a place that does.

 
geogrubb's Avatar
Member

Join Date: Jun 2006
Posts: 2,333
MO

09-04-16, 10:55 AM   #5  
I would suggest putting a strong dose of Seafoam in the fuel tank it will clean up a lot of the varnish, its worth a try. Have a good one. Geo

 
BFHFixit's Avatar
Forum Topic Moderator

Join Date: Jun 2007
Posts: 1,760
KS

09-04-16, 11:34 AM   #6  
High idle with the choke on could well be an intake leak also.


Just needs a bigger hammer
Peace

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

09-04-16, 03:28 PM   #7  
Yep, I thought about that too but the mention of old fuel that was in it pushed me towards a clogged carb. Especially since that's the problem 90% + of the time.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

09-18-16, 11:17 AM   #8  
I found the part # both for the Onan carb rebuild kit (146-0561) and a new carb (146-0526). The rebuild kit is about $135 and a new carb $185, I've looked several places and can't seem to find a good deal. Kind of rich for my blood when I'm not sure it will solve the problem.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

09-18-16, 02:03 PM   #9  
Just be mindful when you take it apart to not tear gaskets. They usually will pop apart without and damage. Clean it well, and put it back together. I wouldn't buy the kit at that price unless I just had to have it. This will cost you nothing other than some time and a can of good quality carb cleaner.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

09-25-16, 06:24 PM   #10  
I haven't had time to take the carb apart and give it a good cleaning yet, but took a short video of the issue I have. It definitely doesn't idle this high functioning normally.


https://www.dropbox.com/s/ntxqvpgmwgfdaps/20160925_211257_9264965294034.mp4?dl=0

 
geogrubb's Avatar
Member

Join Date: Jun 2006
Posts: 2,333
MO

09-25-16, 06:45 PM   #11  
You really should try a strong dose of SeaFoam, it will work wonders on an engine with old gas left in it. Have a good one. Geo

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

07-21-17, 09:11 AM   #12  
https://www.dropbox.com/s/78pywpbcy5u7re9/20170714_204042_10502179892125%20%281%29.mp4?dl=0 I finally got around to cleaning the carb. I put it back together, was able to get the machine started. However, I had trouble getting the throttle and choke linkages working again. The choke plate I believe is in the closed position right now.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

07-21-17, 10:13 AM   #13  
Excellent video, loosen the screw that clamps the cable and pull the cable upwards, making it pull the linkage farther than it is and see if you can't get the choke to move. It looks like it's connected right and working the throttle correctly, just not pulling it far enough.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

07-21-17, 11:32 AM   #14  
Thanks a bunch, I was hesitant to try that before your response, but glad you talked me into it.

I took two more videos. The one below is after I took the carb apart again. The issue is that the throttle linkage is loose - looks like the plastic clip is broken. Maybe a small washer to hold it in place? https://www.dropbox.com/s/apenvj71btnrsl7/20170721_142427_4645783778501.mp4?dl=0

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

07-21-17, 11:35 AM   #15  
Next video is after I got it running again. Since the throttle linkage is not connected, the mower idle can't really be controlled at the moment if I'm using it to mow.

Also, not sure what the proper idle should be - don't want it too low or too high of course. Not sure if this requires a governor adjustment of some sort? https://www.dropbox.com/s/cpu75sw29izpsz6/20170721_141846_4306075187298%20%281%29.mp4?dl=0 Once again, the help is so much appreciated!

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

07-21-17, 01:53 PM   #16  
I think I'm gonna get a little tachometer to figure out the engine speed. $20 on Amazon.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

07-21-17, 07:43 PM   #17  
Yes, as the throttle cable pulls the control arm upwards, it should reach a point where it moves the rod that you loosened. That rod wasn't what I was saying to loosen, the cable clamp is what needs loosening so that you can pull the cable up so that when you put the throttle all the way up, it will engage the choke portion of the controls and close the choke. It should only engage in the last 10% or so of the travel.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

07-22-17, 07:38 PM   #18  
https://www.dropbox.com/s/ejoh5knc9i...15428.jpg?dl=0

Thanks for the follow up help. I linked a pic to the plastic clip that broke while I was trying to take it apart, it was brittle. Not sure if there is a suitable replacement out there, I spent time looking but came up short. This connects the throttle cable rod to the carb.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

07-22-17, 08:39 PM   #19  
Look up a parts breakdown for a kohler CV15S... they used a similar clip on the throttle shaft that will probably work as a direct replacement for yours.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

07-23-17, 10:13 AM   #20  
Thank you! Yes, part # 25-158-08 does look pretty similar and is available online.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

07-23-17, 01:31 PM   #21  
That's not the one... it's the bushing clip that holds the throttle linkage to the governor arm. Lemme go see if I can find a # for it.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

07-23-17, 01:32 PM   #22  
25-158-11-S

This should fit the bill.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

07-24-17, 09:30 AM   #23  
Thanks - I'll give that a shot this week.

 
aerodan1's Avatar
Member

Join Date: Aug 2012
Posts: 112
MA

08-03-17, 04:23 PM   #24  
The part came, was able to modify it a little and was working on tweaking the throttle linkage. However I ran out of gas, went to restart it and the pull rope broke..d'oh! Will have to order a new rope and try again.

 
Search this Thread