OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Is it worth it? Mayfair

No, no start ya bastard. The victa manual says there are 2 types of points/condenser set ups, one has a lgap of 0.685, the earlier version which needs a gap of 0.5 mm, i think mine is the earlier one so set the gap at 0.5. I think we've done well to get this thing to run but as you say, there's not much else we can try

Your manual may be refering to rotomo which had a diffrent set up yours should be
set to 20" i think . Not near my books atm

Then i've set it right as 0.5mm is 20 thou.

Haha blond moment for me .
try your other carby ? Hard nut to crack

Got the other carby working well, reluctant to fiddle with it. Don't think it's the carby as even when i prime the mower with petrol down the spark plug hole it doesn't run.

Did you try another plug ? maby failing under pressure

Did that too, brand new plug bought 2 days ago. I get a bright blue spark with a nice loud snap sound. This is the mower from hell!

Agreed ! I've run out of ideas
did you attempt to start with decomp
Removed and blocked ?

Tried that too! If you were closer, i'd donate it to you. Put the compression gauge on it and it reads 0, i know there is a decompressor outlet but it should still read something.

Nah with decomp there will be virtually none
What happens if you remove and block decomp valve

Tested it and still 0 on compression gauge, other mower with decomp in reads 60. How can i have lost all compression, there is no air leak anywhere and everything is tightly connected????

The cylinder may have to much wear and broke
a ring ?

Took the carby off as well as muffler, rings are ok, piston looks good. I only feel reistance once for every rotation ie the second bit of resistance is fairly weak. It's like i've forgotten to tighten something but i dont know what. I guess i've got to take the engine apart again, does this mean i'll have to replace the gaskets as well, i replaced them a couple of weeks ago? The connecting rod seems a little loose, dont know if it should be connected more tightly to the crankshaft?

Before stripping this down i took the blade plate off, i cannot see a problem with the bottom crank seal but there is slight play there ie if i grab the boss there is some movement there. I'm guessing that the bearing could perhaps be replaced but could this account for a zero reading with compression?

hey,
sounds like the cylinder compression is down , play in the bearings is quiet normal for these engines wont do any damage , because there is fuel getting to the cylinder i still say the crankcase is fine, especially since you found no compression in the cylinder, so i guess its barrel off again.
also conrod play is also normal.
im thinking that the clearance between the cylinder and the piston is excessive and the rings are failing to seal the gap.
dont reach for a drum of fuel and matches yet.

Hi again Mitch, I've read some other websites listing causes of no compression and most say the conrod. Mine is ok, moving the flywheel moves the piston and no strange noises either. You might be right about the clearance between cylinder and piston, a look through the muffler does show a bit of clearance but as you know I changed the rings and the mower did work for a while. What do I do now? And also let me know when I can the fuel and matches out, won't you.

haha don't let it beat you !

sounds more like clearance to me ive never had any conrod issues.
i guess if it is clearance that's the end of it unless you want to get a rebore

Mitch or anyone else, do you know of any specs/tolerances about what is acceptable size for a cylinder bore compared to piston size for a victa?

might have a spare barrel n piston here somewhere , 125 if i remember ? where abouts in melb' are you im on my way down there after the 14th for a break i could drag it with me if it might help maybe have a bit of a looksee too , a hand never hurts most times

G'day vccomm, I'm out in the Eastern suburbs of Melbourne about 15 km out from the city. Really appreciate the offer but I don't know if the mower will last that long. I have an angle grinder aiming straight at it ready to demolish it. On the other hand I'd really like to know how this thing could lose all its compression so quickly, it took so many hours to get it going and then probably ran for about 5 or so mins in total and now nothing. Keep in touch and let me know your movements. It is a 125.