24HP V-Twin B&S - Fault driving me CRAZY!

Scrubcadet10

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Trash it.
:laughing::laughing::wink:
 

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Neo, can you post a You Tube or some sort of video /audio?
 

Neo7

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Neo, can you post a You Tube or some sort of video /audio?

Sorry for the delay gents...Might be able to get this done tomorrow.
 

Neo7

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Ok I've been busy yesterday morning (Australia time) lol!

Firstly this 24HP engine was on good behavior yesterday and wasn't poping much so it took a while to catch the pops on video but this engine has been like this in the past so I'm sure it will get much worse again. Watch the 3 videos and listen for what sounds like a quite sneezes ... This gets much more frequent at higher RPM but you can't hear it (above the general noise of the) on a mobile phone.

So after making these videos I decided to do what I've been so reluctant to do and remove the single barrel carb off my 21HP B&S (in my John Deere) and fitted it to my 24HP engine. Well I did that and Yippeee!!!.... at low RPM the hunting and sneezing was gone!!... Well not quite because there was faint occasional (and random) thud but all in all the engine was far better behaved than the twin barrel setup. This leaves me with questions ....

  1. I now have a working configuration should I just covert the carb and manifold over to a single barrel?... But I need to push a 52" Cutting deck with this engine. Would I lose too much power (technically 3HP) on a single barrel carb or wouldn't it make much difference?
  2. I've previously replaced my twin barrel carb so should I try replacing the plastic manifold (I can see you smiling Boudreaux :laughing:)? .... or even better can I replace the plastic manifold with an older aluminum twin barrel manifold (Part No. 699801)?

Out of the two (or three) options above I actually prefer converting the engine to a single barrel. Engine runs quieter, smoother and starts easier and my 21HP engine has never given me trouble.... But will there be enough power for a 52" Cutting deck ???

Let me know your thoughts gents.:thumbsup:

4 Pops -Link-
Low RPM-Link-
2 Pops-Link-
 

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It seems you have the engine bolted to a stand of some sort but even still, I don't hear much of a "pop" but it certainly runs pretty rough.

Between putting the "new carb / manifold" on and it's improvement, does it run any smoother??

If it's not "popping" with the new carb / manifold (the issue is gone), seems you narrowed it down to the intake / carb. Is one plug burning a different color than the other (whitish / lean)?

A lazer / infrared temp gun pointed close to the exhaust manifold/adjacent to the heads would show if one side is hotter than the other (the hot cylinder is working properly, the other isn't).

I forgot if you tried spraying starting fluid /similar around the manifold (while running) and check for a rise in RPM's(indicating an air leak /lean condition).

I'd examine (and do the above test ) to the intake manifold first. Then go thru the carb again.

Re replacement, I'd try and get a used set up or new if possible. The single barrel for testing should work fine. The lower HP is likely FROM the single barrel carb and NOT having a dual carb set up.

You can always put the engine back on the mower with the single barrel carb and run it, see how she runs. I doubt it'd be a problem...
 
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Neo..... Hell yeah replace that intake with a aluminum one..... I wish you would have said you had one a good while back....

Just make sure and check for FLAT ... Do the sand paper trick..... I would stay with the 2 BBL carb.... It'll run better like that and not to lean .....

Plus Tard Mon Ami ~!~!
 

Neo7

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It seems you have the engine bolted to a stand of some sort but even still, I don't hear much of a "pop" but it certainly runs pretty rough.

Between putting the "new carb / manifold" on and it's improvement, does it run any smoother??

If it's not "popping" with the new carb / manifold (the issue is gone), seems you narrowed it down to the intake / carb. Is one plug burning a different color than the other (whitish / lean)?

A lazer / infrared temp gun pointed close to the exhaust manifold/adjacent to the heads would show if one side is hotter than the other (the hot cylinder is working properly, the other isn't).

I forgot if you tried spraying starting fluid /similar around the manifold (while running) and check for a rise in RPM's(indicating an air leak /lean condition).

I'd examine (and do the above test ) to the intake manifold first. Then go thru the carb again.

Re replacement, I'd try and get a used set up or new if possible. The single barrel for testing should work fine. The lower HP is likely FROM the single barrel carb and NOT having a dual carb set up.

You can always put the engine back on the mower with the single barrel carb and run it, see how she runs. I doubt it'd be a problem...

Yes much smoother.

Sorry I neglected to check the plug colors but Cylinder 2 was still running hotter .... Single barrel Carb is back in my John Deere now so can't check this now.
Can you please explain why the hot cylinder is the one that's working properly?

Yes I've tried spraying the plastic manifold a few times now... But it's never shown anything.

So we have one vote for Single Carb and one vote for staying with the Dual Carb :confused2: :laughing:

Has anyone swapped out a plastic twin barrel manifold for an aluminum twin barrel manifold?... are any modifications required?
 
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Yes much smoother.

Sorry I neglected to check the plug colors but Cylinder 2 was still running hotter .... Single barrel Carb is back in my John Deere now so can't check this now.
Can you please explain why the hot cylinder is the one that's working properly?

Yes I've tried spraying the plastic manifold a few times now... But it's never shown anything.

So we have one vote for Single Carb and one vote for staying with the Dual Carb :confused2: :laughing:

Has anyone swapped out a plastic twin barrel manifold for an aluminum twin barrel manifold?... are any modifications required?

If it fits then you will have to use the flat gaskets, not the orange O ring style.............
 
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