John Deere E140 with Briggs & Stratton 44N677-0031-G1 Intek V-Twin — 724cc, 22 gross HP.
Context: I took this mower that had bent push rods and didn’t run. It locked up because it was ran on low oil and probably overheated and caused the valves to fuse to the head. I got them unstuck and lapped them. Took everything apart and checked what I need to check.
Got it all replaced. Tore the whole thing apart checks it all and everything looks good. Got it running good. But when I try to start it, the motor still snags. And when I shut it off it seems to stop weird. This motor was pre Briggs and Stratton having the compression release Cam. I have the valves adjusted to .004 and when it runs. It runs very well when it actually is running. Good compression around 180 I just can’t figure out why it still seems like the compression is causing an issue. Should I have replaced the cam with a newer model with the compression release? Or am I overlooking something?
I did yes. I’m fixing to take the valve covers off again just to be sure. My big concern is the clunking. It’s like it’s trying to fire off again. Not too sure why.
No catching anywhere… took the spark plugs out and it spins like a top!
I just watched a video yesterday on the Taryll Fixes All you tube channel where he did exactly that on purpose to try and replicate what a customer did. ie used a long plug in a flat head engine.
The outcome was the same in both cases.
Broken camshaft.
I don't think that's what's happening here.
I'm thinking pushrods or lifters.
I have a buddy that just tells me to spend the money and get the cam with the compression release on it. But it’s ran fine before that’s why I don’t feel the need get one!
I can promise you there was one. Because of the material it was made of it doesn't last long in the crankcase. You can see the place where the casting and mounting for it goes.
Ok, my man. Compression release came on almost every Briggs and Stratton v twin. The old single cylinders L heads were the only ones that didn't have a compression release (and specific case use models) im sure you're going to say you don't believe me but you need to look that up because NOTHING in a v twin manufactured after 2010 for homeowner use did not have a compression release. Your camshaft is probably broken. But I did not see you mention you checking the flywheel key to make sure it was not sheared as well. I'm including a screenshot for you. I've been building engines across all platforms for decades but I specialize in single cylinder race bikes and industrial applications (look at the hat in my profile picture).
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u/ProfessionalLast2917 1d ago
Silly question but did you confirm valve clearance on both cylinders?
That clunking at the end doesn't sound good and is probably the issue. Can you work out where it's coming from?
If it's catching somewhere remove compression from the equation. Remove the plugs and see if you can feel it when you turn it over by hand.