Bender,
Most of the techs here are from the USA so V 40 will mean nothing to them.
For the rest of you, the V 40 was a GXV 160 clone out of China which Victa fitted , contry to their del with Briggs & Stratton that triggered the Briggs take over .
I think they came out of the Sanli factory but am not sure.
From what you have posted , t sounds very much like a blown head gasket.
Take the top cover off and look for tell tale oil leaks from the head/ cylinder joint line.
These engines had a lot of problems due to non existent quality control like a lot of the stuff source from China on a least cost basis .
If you got a good one they are great.
The other known major failure is the plastic gear on the cam shaft dropping a tooth or two which puts the valves out of time .
This is a little harder to test and can cause the head gasket to blow so you might have both.
To check the valve timing, remove the spark plug & rocker cover
The cover was siliconed on a lot of them so is difficult to remove without bending it out of shape so be careful.
Put a screwdriver down the plug hole so it touches the piston then slowly rotate the engine while watching the rockers moving the valves
Rotate the engine till the piston is nearest the head and both of the rockers are loose.
This is the firing stroke and the magnets on the flywheel should be just coming past the first leg of the coil
Both of the rockers should stay loose till the piston is almost at the other end of the stroke then the exhaust should start to open and remain open while the piston is coming back to you
Just before it closes the inlet should open and stay open for the entire time the piston is going back away from you.
If this is not happening then the cam is busted
Drain the oil and have a good look for little bits of plastic ( or metal ) in the oil
I don't think it will be a failure of the ignition timing key but wile pulled apart this far it will not hurt to remove the starter cup & nut / bolt that holds the flywheel on.
If you look at it end on there will be 2 rectangles cut into the shaft & flywheel that come together to form a perfect square and in that square is a aluminium key.
This can shear and allow the spark to happen at the wrong time.
This almost never ever happens with any Victa because the swing back blades take the shock of hitting some thing while mowing .
I have never seen one broken &I have pulled down better than 300 engines , but it is only another 10 minutes to check it and rule it in or out.
Bender,
Most of the techs here are from the USA so V 40 will mean nothing to them.
For the rest of you, the V 40 was a GXV 160 clone out of China which Victa fitted , contry to their del with Briggs & Stratton that triggered the Briggs take over .
I think they came out of the Sanli factory but am not sure.
From what you have posted , t sounds very much like a blown head gasket.
Take the top cover off and look for tell tale oil leaks from the head/ cylinder joint line.
These engines had a lot of problems due to non existent quality control like a lot of the stuff source from China on a least cost basis .
If you got a good one they are great.
The other known major failure is the plastic gear on the cam shaft dropping a tooth or two which puts the valves out of time .
This is a little harder to test and can cause the head gasket to blow so you might have both.
To check the valve timing, remove the spark plug & rocker cover
The cover was siliconed on a lot of them so is difficult to remove without bending it out of shape so be careful.
Put a screwdriver down the plug hole so it touches the piston then slowly rotate the engine while watching the rockers moving the valves
Rotate the engine till the piston is nearest the head and both of the rockers are loose.
This is the firing stroke and the magnets on the flywheel should be just coming past the first leg of the coil
Both of the rockers should stay loose till the piston is almost at the other end of the stroke then the exhaust should start to open and remain open while the piston is coming back to you
Just before it closes the inlet should open and stay open for the entire time the piston is going back away from you.
If this is not happening then the cam is busted
Drain the oil and have a good look for little bits of plastic ( or metal ) in the oil
I don't think it will be a failure of the ignition timing key but wile pulled apart this far it will not hurt to remove the starter cup & nut / bolt that holds the flywheel on.
If you look at it end on there will be 2 rectangles cut into the shaft & flywheel that come together to form a perfect square and in that square is a aluminium key.
This can shear and allow the spark to happen at the wrong time.
This almost never ever happens with any Victa because the swing back blades take the shock of hitting some thing while mowing .
I have never seen one broken &I have pulled down better than 300 engines , but it is only another 10 minutes to check it and rule it in or out.
Hi again,
Sadly I'm still in no go city.
I'm attaching some pics to help explain what I'm seeing (or not seeing) as I still can't find the problem.
When I looked at the outside I thought I had a blown head gasket. (Side pic with head assembled).
I removed the spark plug and rocker cover. I checked valve movement for all cycles - it is correct from the perspective the valves open and close when expected to.
I found TDC (both rockers loose) and noted flywheel position re timing. To me this looks slightly off, but I'm a little confused as there are three magnetic points on the flywheel and it lines up with two of them at tdc loose valves. (Rocker cover off pic).
Next I checked the flywheel key location - I couldn't tap the flywheel off. I suspect a little corrosion on the shaft and I didn't want to force it. I will to tap it off from underneath with a rubber mallet when the rain stops. I took a pic of the key position from above with nut and cup removed.
Next I removed the head. The head gasket appears fine - no blow-by on head or cylinder side. (Pics accompanying). There is a little scoring on the bottom of the cylinder, but it's very minimal.
I checked the valve seats, they look okay. No pitting I can see, though I didn't remove them so I can't be certain.
I'm borrowing a compression tester as I can turn the flywheel with one hand with the spark plug in tight. Should I be able to do this? I can feel clear resistance and compression, but I'm not sure if that's a clue.
I double checked the carbi float is working correctly as I thought maybe it's flooding and just pouring in fuel. It's definitely working correctly.
The compression is a grey area for me. I think it should be stronger, but I don't have a number to give you yet.
From the pics, does anything jump out at you that I've missed or got wrong? The three magnetic points on the flywheel have confused me, but the key looks like it's in the right position so I think it's just my being confused.
I appreciate any incite you or anyone else can give.
Cheers and thanks!