briggs and stratton 25hp valve cover not heating up evenly

A

ACF

Well-Known Member
have a b/s model 44t977-0023-g1 on a john deere Z535m, using old school to check coil firing i placed my hand on valve cover one side got hot fast but the other did not heat up, so i suspected that coil was bad so replaced coil no change, checked valve clearance was off a little so adjusted did not result in any change to valve cover heating up my spark tester shows that we have spark and engine does run any one have a clue why there is no heat on one side of engine.

thanks
 
The exhaust side will be hot but not the intake - Never really checked valve cover temps on any engine, On large industrial engines if you felt the intake was hot it told me I had a burnt valve
 
Could be the hot side is running leaner than the cold side. Try this old school test. Remove the shroud so you have access to the intake manifold. Start engine and spray the intake manifold and gasket areas with carb cleaner around the hotter side. What you are looking for is any change in RPMs while doing this. If you see a change that area is sucking in air creating a lean mixture. Patience and a good ear are your friends.
 
I second that. Matter of fact I just got through checking out a Kawasaki FXT00V engine that was just dying engaging the deck. Dropped the exhaust valve push rod. Of course I will going in as the exhaust valve is sticking after parts get here.

I even seen a couple that only struggled to get the deck up to speed while running on one cylinder.
 
Last edited:
To add to the above
Several customers have come in finally for a service because their mower has no balls & bogs down in heavy grass.
They tell me it has been like that from new
A quick inspection shows they are running on 1 cylinder and from the conversations it seems that they were like that from new ( no dealer pre-delivery & no initial service )
In almost every case on pushrod is either chewed up in the sump or just sitting there not connected
It is very common
and on B & S V twins a faulty kill wire that makes one side fire at the wrong time is also quite common.
 
Rivets said:
Could be the hot side is running leaner than the cold side. Try this old school test. Remove the shroud so you have access to the intake manifold. Start engine and spray the intake manifold and gasket areas with carb cleaner around the hotter side. What you are looking for is any change in RPMs while doing this. If you see a change that area is sucking in air creating a lean mixture. Patience and a good ear are your friends.
Click to expand...
did this there was no change in rpm, buddy suggested that muffler was clogged on that side due to color difference on exhaust piping what do you think
 
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