Low Power and getting worse on INTEK 19hp (33R877)

[MRay70]

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I have a 4yr old INTEK that is slowing loosing power. (Engine Model #33R877/0008-G1)
New camshaft - 10/27/23 which fixed the broken compression relief. Seemed to run great after I put it back together.
After mowing six times this year I have low power and it is getting worse.

What I have done so far that has not helped at all:
Tune up 6/01/24 - Air filter, fuel filter, spark plug
Checked flywheel KEY - it was fine
Checked valve adjustment - it was fine
6/7/24 - Replaced carburetor and it runs slightly worse...won't idle all the way down
Always kept good clean oil in it. Because it lugs down more when mowing I removed the deck belt and spun all the spindles and pulleys which were fine.
Questions:
Could the compression relief be stuck giving me low compression (hard to check and never heard of that happening)
I see some INTEK engines have head gasket problems - I see no sign of that, no oil leaks, smoke, or odd sounds.
I have mowed 1/2 acre of level lawn six times and it seems like I have about half the HP I should have.
Thanks for any ideas or things to check.

 

[Alan46]

Could your drive belt be slipping? It would be helpful if you posted the model number and name of your mower!

 

[StarTech]

When these Intek blows you usually will not see smoke or oil leaks as they blow between the cylinder and push rod galley which produce excessive crankcase pressure which vent via PCV system into the filter side of the carburetor. One sign of this is excessive oil usage. Modern oil just don't smoke like older oils so a lot of the time you will not see smoke.

 

[MRay70]

Mower is a Troy Bilt Bronco 42" Model# - 13AL78BS023

I will check for pressure from the PVC hose. Thanks.

 

[StarTech]

If checking the hose you are looking excessive amount present.

But is better to do a leak down test with the rocker cover off. This way if the head gasket is blown between cylinder and the push galley you will hear a louder air sound escape there than at the oil fill tube. Now the sound is louder at oil fill tube then its the rings and cylinder leaking. IE worn out.

 

[GearHead36]

While you're doing the leak down test, I'd also do a compression test.

 

[MRay70]

While you're doing the leak down test, I'd also do a compression test.

I know a compression test would tell the condition of the head gasket however I assumed the compression release on the cam would prevent getting a good reading.

 

[MRay70]

Just ordered a Leak down tester on Amazon. I will have it late next week and will let you know what I find.

 

[Scrubcadet10]

 

[Scrubcadet10]