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I have a Toro lawnmower with a 6.75 Briggs & Stratton 190 cc motor on it and it continues to sputter when it is idle. I have changed everything
- Thread starter Paul’s Toro
- Start date
Cajun power
Active Member
look at carb gaskets closest to engine air intake. It's possible you might have an air leak...
not totally familiar with this engine, but if it has one of those hard plastic block intake-to-carb spacers, look for a crack..look for any small crack or defect in the carb body itself...like maybe a missing welch plug?
at high rpm...wot, will tend to "hide" an air leak...but at lower rpm, idle, rough.
as others have commented...make sure linkage and spring from governor to throttle valve is correct along with any damping springs (often its a two spring setup)...also check choke valve...it should move freely stop to stop.
not totally familiar with this engine, but if it has one of those hard plastic block intake-to-carb spacers, look for a crack..look for any small crack or defect in the carb body itself...like maybe a missing welch plug?
at high rpm...wot, will tend to "hide" an air leak...but at lower rpm, idle, rough.
as others have commented...make sure linkage and spring from governor to throttle valve is correct along with any damping springs (often its a two spring setup)...also check choke valve...it should move freely stop to stop.
Paul’s Toro
Member
You are correct.I think the confusion when an engine is at full speed, by definition, that is *NOT* idle in any way, shape, or form! I think a better choice of words may be "sputters under full speed, no load, conditions", and the confusion is not helping.
Sputters at full speed with no load.
Have you checked the RPMs with a accurate RPM gauge?
We should be careful in our discussions about saying full throttle and things like that because even though it's easy to do we're really in our minds, not talking about full throttle.
Full throttle by definition means when the carburetor is at its furthest over position with the throttle plate or butterfly as some people call it, wide open and on a lawn mower that would make the RPMs at least 2,000 if not 3000 RPMs faster than full operating speed.
The best way to determine if this is anywhere fuel related would be to get it running and get it set at between $2,900 and 3100 RPMs and then use a folded microfiber towel or shop cloth at the carburetor hole to slightly restrict the air flow. See if restricting it makes it run better or if it makes it start to burble even worse.
Also try gapping your plug at .025-.026 as sometimes you'll find a slightly weak emission system that doesn't play nicely. Also can try a standard j19 LM versus the RJ so you don't have a resistor plug or vice versa because sometimes it makes a difference but only about one in a 1000 or more.
We should be careful in our discussions about saying full throttle and things like that because even though it's easy to do we're really in our minds, not talking about full throttle.
Full throttle by definition means when the carburetor is at its furthest over position with the throttle plate or butterfly as some people call it, wide open and on a lawn mower that would make the RPMs at least 2,000 if not 3000 RPMs faster than full operating speed.
The best way to determine if this is anywhere fuel related would be to get it running and get it set at between $2,900 and 3100 RPMs and then use a folded microfiber towel or shop cloth at the carburetor hole to slightly restrict the air flow. See if restricting it makes it run better or if it makes it start to burble even worse.
Also try gapping your plug at .025-.026 as sometimes you'll find a slightly weak emission system that doesn't play nicely. Also can try a standard j19 LM versus the RJ so you don't have a resistor plug or vice versa because sometimes it makes a difference but only about one in a 1000 or more.
Paul’s Toro
Member
Have you checked the RPMs with a accurate RPM gauge?
We should be careful in our discussions about saying full throttle and things like that because even though it's easy to do we're really in our minds, not talking about full throttle.
Full throttle by definition means when the carburetor is at its furthest over position with the throttle plate or butterfly as some people call it, wide open and on a lawn mower that would make the RPMs at least 2,000 if not 3000 RPMs faster than full operating speed.
The best way to determine if this is anywhere fuel related would be to get it running and get it set at between $2,900 and 3100 RPMs and then use a folded microfiber towel or shop cloth at the carburetor hole to slightly restrict the air flow. See if restricting it makes it run better or if it makes it start to burble even worse.
Also try gapping your plug at .025-.026 as sometimes you'll find a slightly weak emission system that doesn't play nicely. Also can try a standard j19 LM versus the RJ so you don't have a resistor plug or vice versa because sometimes it makes a difference but only about one in a 1000 or more.
Paul’s Toro
Member
Thanks for the info.
I appreciate it
I appreciate it
blaster 2023
Member
How old is the Gas?
Paul’s Toro
Member
New 89 octane.How old is the Gas?
also cleaned out the gas tank.
first pull
Member
Could be a valve stickingI have a Toro lawnmower with a 6.75 190cc Briggs & Stratton motor on it that continues to sputter when idling. I have changed the oil, the spark plug, the air filter and the carburetor and it still sputters.
Check the governor make sure that’s it and working right before you dig too deepI have a Toro lawnmower with a 6.75 190cc Briggs & Stratton motor on it that continues to sputter when idling. I have changed the oil, the spark plug, the air filter and the carburetor and it still sputters.