Head Gasket Keeps Blowing

[darrinster]

Electric PTO's are sudden death.
It is either off or on, no slip so it puts an instant load on the engine.
The load on the engine makes it slow down so the governor opens up the throttle and pumps in the gas.
The engine slowing under load is the same as you backing off and developes a high vacum load which will suck oil past your rings ( or gasket ) if there is any gaps.
Then the engine picks back up so you get a little puff of whits smoke from the ooil then black smoke from the extra gas.
You notice this more an small engines and in particular from small single cylinder engines.
With the head gasket sorted you should not get the white smoke but the black smoke may persist.

When I get it all back together I will record it starting and engaging the blades.

 

[cpurvis]

Electric PTO's are sudden death.
It is either off or on, no slip so it puts an instant load on the engine.
The load on the engine makes it slow down so the governor opens up the throttle and pumps in the gas.
The engine slowing under load is the same as you backing off and developes a high vacum load which will suck oil past your rings ( or gasket ) if there is any gaps.
Then the engine picks back up so you get a little puff of whits smoke from the ooil then black smoke from the extra gas.
You notice this more an small engines and in particular from small single cylinder engines.
With the head gasket sorted you should not get the white smoke but the black smoke may persist.

Those two sentences in bold conflict with each other. Opening the throttle increases manifold pressure, not the other way around.

The on/off (i.e., no gradual application) nature of the electric clutch is why I engage the mower at a barely-above-idle engine speed and then bring the engine up to operating rpm. I also eliminated the nanny-state mower shutdown switches so that I don't put a hundred unnecessary disengage/engage cycles on the clutch every time I mow.

 

[motoman]

The clunking...a basic issue. Was the engine properly torqued to the chassis and the PTO to the engine? When I had my Intek out I could not find torque values for the hold down bolts so I used the bolt head markings and a chart. The clunking reminds me of shot engine or trans mounts on a car everything moves around with power application. Just a thought. Also the white puffs on closing and then opening throttle may be partially due to valve guide clearance (wear) or bad seal (s).

 

[darrinster]

I put another OEM Briggs gasket on again and did a super clean of the gasket surface.

If you guys can watch the video I recorded of the engine running and can see if you hear any issues. I don't really want to throw much more money into it. If I throttle the engine up quickly it's puffing out white smoke.

Here is the video https://www.youtube.com/watch?v=7qTu1uRHamA Another video showing the blades being engaged. Is the sound normal? https://www.youtube.com/watch?v=AU0hIY41l2E

*EDIT* Added better quality video. Some of the rattle is the muffler and the heat shield. The shroud is not bolted down.

 

[darrinster]

*Update*

I drained the 10w30 oil which smelled a little like gas. I put in SAE 30. Instead of white smoke puffing out when engaging the blades, it's black. Which is a great improvement to me as my other riding mower does this and it has never gave me any problems.

With a combination of:

1: The wrong Intake Push Rod being too long and hitting the valve cover and I think it was not allowing the oil to re-enter the crankcase, as there was a huge amount of oil in the valve cover after running. ( I installed new Intake and Exhaust Push Rods)

2: 4 Different size Head bolts. I replaced all 8, with new correct bolts. I torqued them down in small amounts in inch pounds. 50, 100, 150, 200, 220, Finally 230 for just a little extra torque just to make sure it was not under torqued. Each torque amount I checked it 3 times. Worth the extra time so you know it's correctly torqued.

Did some mowing and everything seems to be good now. The engine does not shake like it use to when engaging the blades.

Thanks to everyone for their help. Hopefully this holds up.