WinterDeere
Super Member
- Joined
- Sep 6, 2011
- Messages
- 5,965
- Location
- Philadelphia
- Tractor
- John Deere 3033R, 855 MFWD, 757 ZTrak; IH Cub Cadet 123
Welp... ran leak tests on both cylinders, hoping this was "just" a blown head gasket, since that would be a lot easier than dealing with the damn breather. Unfortunately, both cylinders look reasonably good:
left: 17%
right: 23%
This tester shows up to 40% is "good". Not sure why right is higher than left, and Deere/Kawi don't publish a spec on this, but both are well within the green range on my gauge.
I tried testing the breather with the blow/suck test on the dipstick tube, and was able to move air thru the crankcase in both directions, which would register as a "stuck open" reed.
Despite all this, I'm still wondering if I should pull the heads before tearing the whole motor down to get to the breather reed, mostly because I'm not sure why a bad breather would cause the engine to pop and run rough, and partly because the reed replacement is such a nightmare I want to make sure I checked every other possible box first.
Procedure to remove that breather reed valve is horrible:
left: 17%
right: 23%
This tester shows up to 40% is "good". Not sure why right is higher than left, and Deere/Kawi don't publish a spec on this, but both are well within the green range on my gauge.
I tried testing the breather with the blow/suck test on the dipstick tube, and was able to move air thru the crankcase in both directions, which would register as a "stuck open" reed.
Despite all this, I'm still wondering if I should pull the heads before tearing the whole motor down to get to the breather reed, mostly because I'm not sure why a bad breather would cause the engine to pop and run rough, and partly because the reed replacement is such a nightmare I want to make sure I checked every other possible box first.
Procedure to remove that breather reed valve is horrible:
- Remove engine from mower
- Remove front engine shroud and cooling fan
- Remove flywheel (I've already done thru here)
- Remove intake manifold
- Remove valve covers
- Remove rockers
- Remove push rods
- Remove rear crank case cover
- Flip engine
- Remove cam shaft & thrust washer
- Remove tappets (lifters)
- Remove breather cover
- Remove breather pipe
- Remove reed valve body
- Inspect/replace reed valve
- Reverse assembly, replacing all gaskets
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