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B&S 20hp (331777-2372-G5) runs wide open after you start it?

#1

B

Bat57

Have a B&S 20 HP engine that the compression release lever broke on. Cleaned everything out and put new camshaft in and everything back in exactly like suppose to be. New plug, new oil. Took carburetor apart and cleaned it all out and everything on it was good. Checked linkage and springs for carb, everything good and in the right place. Adjusted valves, they are good. Engine started fine but stays running at almost full throttle and cant be adjusted with the throttle control lever. Runs good just cant control engine speed. Cables and springs for all linkage is there and seems to works fine. Need some help. I cant figure this out.


#2

StarTech

StarTech

Have you done the static governor adjustment? Also you did put back the oil slinger/ governor assy?


#3

B

Bat57

I put back the oil slinger/ governor assembly and lined it up with governor arm. I did the governor arm adjustment a little while ago and it still runs almost full throttle and cant idle down with throttle control. Don't know how to tell if the governor assembly is bad or not.


#4

B

Bat57

StarTech said:
Have you done the static governor adjustment? Also you did put back the oil slinger/ governor assy?
Click to expand...
I put back the oil slinger/ governor assembly and lined it up with the governor arm, I did the governor arm adjustment a little while ago and it still runs almost full throttle and cant idle down with the throttle control. Don't know how to tell if the governor assembly is bad or not.


#5

StarTech

StarTech

You basically have done the test if you did the static adjustment correctly. So it does sounds like a bad governor.


#6

B

bertsmobile1

As the others have mentioned.
The Governor GOVERNONS and just like the one in town hall, it SLOWS things down
So a racing engine will always be a governor problem
Do your static adjustment and remember when the throttle butterfly is fully open the governor rod has to move towards the closed position.
If not you have it backwards.
If a couple of static adjustments don't fix things then something is wrong inside the engine .
Most governors have some sort of cap on them and these have a bad habit of vanishing when the engine is apart ( gremlins ) or falling off when you are assembling the engine.
On some you can even install the lever upside down.
We have all done it, just some won't admit it .


#7

B

Bat57

StarTech said:
You basically have done the test if you did the static adjustment correctly. So it does sounds like a bad governor.
Click to expand...
Thanks, I will replace the governor and see if that works.


#8

B

Bat57

bertsmobile1 said:
As the others have mentioned.
The Governor GOVERNONS and just like the one in town hall, it SLOWS things down
So a racing engine will always be a governor problem
Do your static adjustment and remember when the throttle butterfly is fully open the governor rod has to move towards the closed position.
If not you have it backwards.
If a couple of static adjustments don't fix things then something is wrong inside the engine .
Most governors have some sort of cap on them and these have a bad habit of vanishing when the engine is apart ( gremlins ) or falling off when you are assembling the engine.
On some you can even install the lever upside down.
We have all done it, just some won't admit it .
Click to expand...
Thanks, I will recheck everything and then replace governor if nothing changes for the better.


#9

K

keakar

Bat57 said:
I put back the oil slinger/ governor assembly and lined it up with governor arm. I did the governor arm adjustment a little while ago and it still runs almost full throttle and cant idle down with throttle control. Don't know how to tell if the governor assembly is bad or not.
Click to expand...
only way to know that is pull the sump off again and check it

but first i would check to see if the carb is flooding and that the main jet inside the plastic tube didnt fall out on you and get lost. if that jet falls out it will be dumping way too much gas in the engine. redoing the carb is a lot easier then pulling the sump


#10

B

Bat57

bertsmobile1 said:
As the others have mentioned.
The Governor GOVERNONS and just like the one in town hall, it SLOWS things down
So a racing engine will always be a governor problem
Do your static adjustment and remember when the throttle butterfly is fully open the governor rod has to move towards the closed position.
If not you have it backwards.
If a couple of static adjustments don't fix things then something is wrong inside the engine .
Most governors have some sort of cap on them and these have a bad habit of vanishing when the engine is apart ( gremlins ) or falling off when you are assembling the engine.
On some you can even install the lever upside down.
We have all done it, just some won't admit it .
Click to expand...
Thanks for your help. I have put a new camshaft, tappet, oil pump shaft, governor/ oil slinger assembly, checked the governor shaft, no play and once back together and once back together I checked carb butterflies and linkage, everything good. Checked adjustment on governor arm all good. Started engine and still running at almost full throttle with no throttle lever control to so it down but can increase speed a little with throttle.


#11

B

Bat57

keakar said:
only way to know that is pull the sump off again and check it

but first i would check to see if the carb is flooding and that the main jet inside the plastic tube didnt fall out on you and get lost. if that jet falls out it will be dumping way too much gas in the engine. redoing the carb is a lot easier then pulling the sump
Click to expand...
Thanks, carb is fine, cleaned and put back together jet is there. Butterflies working properly cant figure this out.


#12

B

Bat57

StarTech said:
You basically have done the test if you did the static adjustment correctly. So it does sounds like a bad governor.
Click to expand...
Put new governor in and same problem, still running at almost full throttle and cant control with throttle lever.


#13

StarTech

StarTech

How are you doing the static governor adjustment?


#14

B

Bat57

StarTech said:
How are you doing the static governor adjustment?
Click to expand...
Loosening the nut on the governor arm, holding arm in full throttle position then turning governor shaft clockwise until it touches governor then tightening the nut.


#15

StarTech

StarTech

Well that is the right way just making sure. I double checked two engines here that full throttle was full CW. Hmmm should be working-- Is governor arm even moving when the engine is running? Almost sound like the carburetor is on backwards but that would be a little hard to do or a missing throttle plate. just thinking out loud.


#16

B

Bat57

StarTech said:
Well that is the right way just making sure. I double checked two engines here that full throttle was full CW. Hmmm should be working-- Is governor arm even moving when the engine is running? Almost sound like the carburetor is on backwards but that would be a little hard to do or a missing throttle plate. just thinking out loud.
Click to expand...
No problem, I appreciate the help, this thing is driving me crazy, I have went through the carb several times and it is working correctly. I have a B&S 21hp engine on my other mower and they are set up the same. Linkage and lever movements are the same and work the same. So I double checked all linkage on 20hp and it is right. I have done static adjustment on both old and new governor. Same result, runs wide open. Could an air leak between the carb and the head cause this kind of reaction?


#17

B

bertsmobile1

Might be worthwhile to visually check the linkages as some throttles have both a push & pull hole in the butterfly.
so pull the throttle control on and note which way the governor arm moves .
It should be opening the throttle
With the throttle wide open, the only way the governor arm should be able to move is to close the butterfly.
I always try to ignore the CW or CCW directions because most engines can be set up for left or right hand controls and some butterflys pull open while others push open
Remember the governor works against the throttle control so as you throttle up the spring on the governor arm stretches


#18

B

Bat57

bertsmobile1 said:
Might be worthwhile to visually check the linkages as some throttles have both a push & pull hole in the butterfly.
so pull the throttle control on and note which way the governor arm moves .
It should be opening the throttle
With the throttle wide open, the only way the governor arm should be able to move is to close the butterfly.
I always try to ignore the CW or CCW directions because most engines can be set up for left or right hand controls and some butterflys pull open while others push open
Remember the governor works against the throttle control so as you throttle up the spring on the governor arm stretches
Click to expand...
Thanks for the info. I have checked the linkage assembly and the holes in the butterfly levers on the carb. There are only two holes on the front butterfly that connects to the governor arm. One for control rod and one for the spring, and same on governor arm. I have a 21hp B&S engine from same 330000 series engine with same carb and linkage set up and I have checked using it as a reference and they are both set up the same way. The 21hp runs great with no issues so I actually took the governor rod & spring from it and no difference when I put it on the 20hp. I put new governor in and readjusted arm and still same thing. I loosened the governor arm and pushed it forward to full throttle then I turned the governor shaft up against the governor and tightened the governor arm back up. No change. I cant figure out what is causing this thing to run almost wide open when you start in up. The throttle control lever will speed it up a little but will not slow it down but a hair. Have even checked the throttle cable and you can see it move back and forth with no issues.


#19

B

bertsmobile1

By front I do hope you mean closest to the engine which most would call rear


#20

L

Luffydog

Can you move the governor rod to carb freely or it is hard to move. If it is stiff and won the move the carb linkage it is wrong. I have seen the governors make spiral like a bolt on the shaft they are on if so that part is made into the block and not replaceable and new a new motor. Check the linkage first and if not moving free you have it adjusted wrong and if it does move free then it is internal under the governor.


#21

B

Bat57

bertsmobile1 said:
By front I do hope you mean closest to the engine which most would call rear
Click to expand...
Yes it is the one closest to the engine.


#22

B

Bat57

Luffydog said:
Can you move the governor rod to carb freely or it is hard to move. If it is stiff and won the move the carb linkage it is wrong. I have seen the governors make spiral like a bolt on the shaft they are on if so that part is made into the block and not replaceable and new a new motor. Check the linkage first and if not moving free you have it adjusted wrong and if it does move free then it is internal under the governor.
Click to expand...
Thanks, have done all that and everything moving freely and working like it is suppose too.


#23

C

cruzenmike

I had this exact same issue and I replaced the governor and it fixed the problem. When doing both the static and dynamic governor adjustments on the linkages, you have to be certain that you are turning the governor shaft the correct direction. If not you will end up allowing the engine to race up. I am not sure if you are referencing a service manual for your exact engine, but be sure to check this all out. When I took my crankcase off of my engine I found the governor in pieces.

Here is a link to my post a couple of years back when I was having this problem. A great guy on here provided me with the service manual from Briggs and I was able to properly adjust the governor.

www.lawnmowerforum.com

44M777 24hp ELS Revving Uncontrollably

Hello. I was experiencing some hunting/surging on my Briggs v-twin so I attempted to adjust the governor. Now when I start the mower, it revs uncontrollably. It is revving so high the engine is going to explode! I have tried over and over to adjust the governor but nothing I do fixes the...
www.lawnmowerforum.com www.lawnmowerforum.com


#24

B

Bat57

cruzenmike said:
I had this exact same issue and I replaced the governor and it fixed the problem. When doing both the static and dynamic governor adjustments on the linkages, you have to be certain that you are turning the governor shaft the correct direction. If not you will end up allowing the engine to race up. I am not sure if you are referencing a service manual for your exact engine, but be sure to check this all out. When I took my crankcase off of my engine I found the governor in pieces.

Here is a link to my post a couple of years back when I was having this problem. A great guy on here provided me with the service manual from Briggs and I was able to properly adjust the governor.

www.lawnmowerforum.com

44M777 24hp ELS Revving Uncontrollably

Hello. I was experiencing some hunting/surging on my Briggs v-twin so I attempted to adjust the governor. Now when I start the mower, it revs uncontrollably. It is revving so high the engine is going to explode! I have tried over and over to adjust the governor but nothing I do fixes the...
www.lawnmowerforum.com www.lawnmowerforum.com
Click to expand...


#25

B

Bat57

cruzenmike said:
I had this exact same issue and I replaced the governor and it fixed the problem. When doing both the static and dynamic governor adjustments on the linkages, you have to be certain that you are turning the governor shaft the correct direction. If not you will end up allowing the engine to race up. I am not sure if you are referencing a service manual for your exact engine, but be sure to check this all out. When I took my crankcase off of my engine I found the governor in pieces.

Here is a link to my post a couple of years back when I was having this problem. A great guy on here provided me with the service manual from Briggs and I was able to properly adjust the governor.

www.lawnmowerforum.com

44M777 24hp ELS Revving Uncontrollably

Hello. I was experiencing some hunting/surging on my Briggs v-twin so I attempted to adjust the governor. Now when I start the mower, it revs uncontrollably. It is revving so high the engine is going to explode! I have tried over and over to adjust the governor but nothing I do fixes the...
www.lawnmowerforum.com www.lawnmowerforum.com
Click to expand...
Sorry, accidently hit the post button before I typed anything. I replaced the camshaft due to broken compression release valve. Put new one in and checked governor and nothing wrong with it. Reassembled the engine, cleaned and reinstalled the carburetor assembly, hooked all the linkage back up and double checked against manual and another motor from same series. Started motor and it ran at almost full throttle. Shut engine down then loosened nut on governor arm and pulled the throttle all the way open then turned governor shaft until it touched the governor, retightened arm nut. Started engine again, same outcome, almost full throttle and couldn't control with lever. Broke engine apart and installed new governor. Put everything back together, double checked all linkage, did arm adjustment again. Started engine and same exact thing happening again. Engine running at almost full throttle. Thanks for your help.


#26

C

cruzenmike

It sounds like you have everything covered, but it is possible that you missed something. Did you by chance replace the governor springs and are they in the correct slots on the governor linkage? These springs can become stretched and result in surging or excessive revving. If I remember correctly, my governor linkage had 2-3 springs and had to be set up just right to ensure that it work properly.

In the end, if you are 100% sure that the governor is not to blame for the problem, then you might want to look at completely rebuilding the carburetor. There is a point where ethanol does damage to rubber o-rings within the carb that cannot be resolved with a simple cleaning. On my ELS I had to remove the two jets and replace the o-rings around them because it was surging. A more catastrophic failure of the carb might lead to excess fuel getting in.

One last thing to look at, in the manual that is linked in my post, look at the adjustment for the RPM. You will need to have a tiny tach or similar. Start with setting the minimum no load RPM. Then you can do a top no load RPM. Of course be careful. If the engine is really racing, you do not want to do this or mess with the governor linkages while it is running at excessive speeds. You can find out your exact RPMs for your engine code by reaching out to your dealer or posting on this site. There are a few Briggs techs who can give you the information that you need.


#27

StarTech

StarTech

cruzenmike said:
It sounds like you have everything covered, but it is possible that you missed something. Did you by chance replace the governor springs and are they in the correct slots on the governor linkage? These springs can become stretched and result in surging or excessive revving.
Click to expand...
You misunderstand the purpose governor springs. When stretched they do not causing over revving; surging maybe if the spring rates are wrong but just lower than normal governed speed most times. Governor springs pulls the throttle to full speed and then either the pneumatic, air vane, or mechanical governor pushes to slow the engine speed back toward idle speed not the other way around until things balances out.


#28

B

Bat57

cruzenmike said:
It sounds like you have everything covered, but it is possible that you missed something. Did you by chance replace the governor springs and are they in the correct slots on the governor linkage? These springs can become stretched and result in surging or excessive revving. If I remember correctly, my governor linkage had 2-3 springs and had to be set up just right to ensure that it work properly.

In the end, if you are 100% sure that the governor is not to blame for the problem, then you might want to look at completely rebuilding the carburetor. There is a point where ethanol does damage to rubber o-rings within the carb that cannot be resolved with a simple cleaning. On my ELS I had to remove the two jets and replace the o-rings around them because it was surging. A more catastrophic failure of the carb might lead to excess fuel getting in.

One last thing to look at, in the manual that is linked in my post, look at the adjustment for the RPM. You will need to have a tiny tach or similar. Start with setting the minimum no load RPM. Then you can do a top no load RPM. Of course be careful. If the engine is really racing, you do not want to do this or mess with the governor linkages while it is running at excessive speeds. You can find out your exact RPMs for your engine code by reaching out to your dealer or posting on this site. There are a few Briggs techs who can give you the information that you need.
Click to expand...
Thanks for the info. Will check everything again with new info.


#29

C

cruzenmike

StarTech said:
You misunderstand the purpose governor springs. When stretched they do not causing over revving; surging maybe if the spring rates are wrong but just lower than normal governed speed most times. Governor springs pulls the throttle to full speed and then either the pneumatic, air vane, or mechanical governor pushes to slow the engine speed back toward idle speed not the other way around until things balances out.
Click to expand...

So based upon what you are saying, it HAS to be the governor that is set up incorrectly on the OPs engine. I could not recall whether or not the governor had a natural tendency to open or close the carb via the linkages. Only makes sense, that like in air brakes, the configuration would be to the safest "condition" and in this case it would be the minimum no load RPM.

When adjusting my governor I had made the mistake of turning the governor shaft the wrong way and securing it which did not allow for it to operate properly. The OP should try doing the opposite of what he has tried already and see if the issue resolves. I could be wrong (again) but different engines might have different governor setups?


#30

B

Bat57

cruzenmike said:
So based upon what you are saying, it HAS to be the governor that is set up incorrectly on the OPs engine. I could not recall whether or not the governor had a natural tendency to open or close the carb via the linkages. Only makes sense, that like in air brakes, the configuration would be to the safest "condition" and in this case it would be the minimum no load RPM.

When adjusting my governor I had made the mistake of turning the governor shaft the wrong way and securing it which did not allow for it to operate properly. The OP should try doing the opposite of what he has tried already and see if the issue resolves. I could be wrong (again) but different engines might have different governor setups?
Click to expand...
Thanks, I will recheck this.


#31

C

cruzenmike

Bat57 said:
Thanks, I will recheck this.
Click to expand...

Have you been able to figure it out. I hope it is something simply!


#32

B

Bat57

cruzenmike said:
Have you been able to figure it out. I hope it is something simply!
Click to expand...
Thanks for your help. It turned out to be the linkage and the owner for whatever reason had messed with both adjustment screws on the Nikki carburetor, I didn't find this out until I got aggravated and decided to completely tear the carb apart to recheck everything and found the adjustment screws were out of factory settings.


#33

B

Bat57

StarTech said:
You basically have done the test if you did the static adjustment correctly. So it does sounds like a bad governor.
Click to expand...
Thanks for your help. It turned out to be the linkage and the owner for whatever reason had messed with both adjustment screws on the Nikki carburetor, I didn't find this out until I got aggravated and decided to completely tear the carb apart to recheck everything and found the adjustment screws were out of factory settings


#34

B

Bat57

bertsmobile1 said:
As the others have mentioned.
The Governor GOVERNONS and just like the one in town hall, it SLOWS things down
So a racing engine will always be a governor problem
Do your static adjustment and remember when the throttle butterfly is fully open the governor rod has to move towards the closed position.
If not you have it backwards.
If a couple of static adjustments don't fix things then something is wrong inside the engine .
Most governors have some sort of cap on them and these have a bad habit of vanishing when the engine is apart ( gremlins ) or falling off when you are assembling the engine.
On some you can even install the lever upside down.
We have all done it, just some won't admit it .
Click to expand...
Thanks for your help. It turned out to be the linkage and the owner for whatever reason had messed with both adjustment screws on the Nikki carburetor, I didn't find this out until I got aggravated and decided to completely tear the carb apart to recheck everything and found the adjustment screws were out of factory settings


#35

B

Bat57

keakar said:
only way to know that is pull the sump off again and check it

but first i would check to see if the carb is flooding and that the main jet inside the plastic tube didnt fall out on you and get lost. if that jet falls out it will be dumping way too much gas in the engine. redoing the carb is a lot easier then pulling the sump
Click to expand...
Thanks for your help. It turned out to be the linkage and the owner for whatever reason had messed with both adjustment screws on the Nikki carburetor, I didn't find this out until I got aggravated and decided to completely tear the carb apart to recheck everything and found the adjustment screws were out of factory settings


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