OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines something went wrong today

hi guys,

today while mowing with my recently rebuilt utility [series 80 engine] the height adjuster let go, the blade dug into the dirt and stalled the engine at full speed.

now it wont run much more than 30 seconds or so

im thinking the head gasket has blown due to the compression lockup the same way a car does it

does anyone have any different ideas?

im hoping nothing major but would like some opinions before i strip it down.

thanks.

Hi,
If you remove the decompression valve and put an old spark plug in its place (just to block it up) are you able to test the compression by turning the blades with spark plug disconnected and finger over the spark plug hole. Any hissing from the gasket?

There is no particular reason for high pressures to develop in the cylinder as a result of the engine coming to a sudden stop. It seems a lot more likely the flywheel key has sheared, and the ignition timing is now hopelessly wrong. I suggest you check the key and keyways.

In the case of a car engine, sometimes they come to a sudden stop as a result of water in a cylinder, caused by a blown head gasket. The water causes the sudden stop - the sudden stop doesn't cause the water. Incidentally if that happens while the car is in motion, there is little chance of saving the piston and/or connecting rod. If it happens while the engine is just cranking, most times no harm is done. However I can recall a couple of people who have managed to ruin an engine with a hydraulic lock, by towing the car and engaging the clutch. In one case with a Holden grey motor the center main bearing cap ended up laying on the bottom of the sump. In the other case it was a brand new diesel 4WD that got a drink while crossing a creek. Attempts to rotate the engine by towing the car resulted in a new piston, rod, and crankshaft. Wasn't covered by warranty, either.

hi guys there is no apparent leaking from the head and this engine's flywheel is located by a D on the crankshaft so i think it is rather unlikley that that has moved i could be wrong about that though

i now know the throttle cable is bent at the carby end and i think that maybe it had popped out [i didnt notice when i took the carby off] i think the carby may be stuck at a low rev range causing the engine to stall out the way it did with a bit of luck maybe a new cable will sort it out but that has to wait till next week as ive got other things to take care of i will let you guys know.

well i suppose i could try to straighten the cable and give it another try might give that a go if i get time this weekend im not sure yet but i might be going down near young to visit the oldies.

I would look innto the carby, Make sure that cable moves freely.

The flywheel could still have taken some damage, I would suggest taking a look to check the d-flat sidehas not warped, and that no cracking or splitting has occured in the wheel.

Also a good idea to have a close look at the state of the disk after this kind of thing, it could have caused damage to the disk or blades.