Haha now let me make it clear from the get go the PREVIOUS owner of this 550 Pro did the damage to this machine - not me. When I bought a couple of working 550 Pro's from him he tossed this one in at no charge stating he felt it was an 'easy repair'.
Essentially what he did was in advertently drill through the engine block and into the cylinder. I do not have any idea what he was thinking but thats what he did.
He stated the mower was fully working prior to his doing this - as mentioned he thought it might be an easy repair - he suggested I weld it shut. I've put a small red plastic marker just to show the hole spot, it's about 3mm in diameter.
I've taken the starter rope off and removed a small amount of the metal filings and also a broken drill bit he'd dropped in there.
I'm unsure if its worth trying to repair this previous owners damage or simply use the mower for parts....as I do have 2 other fully working 550 Pro's.
Haha again I did not do the damage or the horrible all over black spray paint job ;-)
Oh ok, wow pleasantly surprised that its so clearly fixable - thats good as he said it was one of the better ones he had before he did that damage to it.
Surprised that such basic fixes are acceptable - might see how welding it goes first - only have a basic arc welder and am no pro at it but should be able to plop a bit to fill it easy enough - if it's tricky I'll go the other routes - the pop rivet one actually seems pretty fool proof as well.
Originally Posted by Mowerfreak
Use grease to capture the shavings if you take that route.
Hi MF, can you give anymore info on how you'd recommend doing this? I was just planning on flushing the cylinder out with some old petrol or kero etc so no shavings were left in there, but open to better approaches to ensure this is thoroughly done. :-)
Hi N1KKO, I remember a guy who helicoiled my spark plug hole in the cylinder head using grease to catch metal shavings as he tapped it. I wish I had filmed it as I can't recall the exact method. I imagine the grease in the spaces of the tap will be effective in catching the shavings and holding them as it cuts a thread. What few if any fall in should be able to be flushed out with petrol or physically vacuumed out.
Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
He obviously had a broken stud in the pull starter and drilled it out but went a bit too far. Do not attempt to weld it as it is cast iron and you need cast rods and it is problematic unless you have a fair bit of experience. Any of the above ideas will work just make sure whatever you fit doesn't protrude down into the cylinder as the piston will hit it. I can't believe somebody gave up so easily on it without asking around because the fix is not that hard, about a 5 min fix.
It doesn't look like enough metal to thread that hole if you do it looks like you would only get a couple of threads cut and then you will have trouble when fitting a rivet into the transfer port , that it could protrude into the port restricting flow.
Personally I would not bother fixing this as you can buy a complete mower for $10 at a tip shop or someone will give you a Victa 2 stoke for free but if I was going to fix this I would turn the motor upside down and braze the hole from underneath with oxyacetylene so nothing is protruding into the port.
While Max's method would be the best, I'd just drill out to the right rivet size and use a sealed blind rivet with a smear of JB weld. The bit protruding in the transfer port should have negligible effect on flow (after all we're not building a race engine). Rotate the piston to TDC and stuff a rag in the bore to catch and filings when you drill the hole.
If it doesn't work, nothing lost, just put a $10 motor on it or part it out., just make sure you use a sealed blind rivet as they're designed to be water tight.
Much thanks to everyone for the terrific suggestions - I will heed all of them and NOT try to weld it - I'll likely try the blind rivet with some high temp epoxy first then see about the other options - I figured this mower was good for parts only so if I'm able to get it going that'd be gravy.
Much thanks again, really appreciate the assistance and terrific ideas.
PS. NormK was spot on with how the previous owner damaged it - thats exactly what he said he was doing - well done sir! FWIW I think he gave up on the repair so fast as he had about 8 550 Pro's! Seriously.....his late father had been a huge fan of them and cleaned up every one he could get from a local council when it changed over to 4 strokes. He was trying to make room in his shed and selling them off - hence he tossed this 'damaged' one in when he sold me one. In the end he gave me 2 working ones, this damaged one and another 3/4 of one that was broken down for parts for $300. Cost me $100 in fuel to drive to buy them but wasn't a bad deal considering they're somewhat sought after if the SP is working well, which it is on the 2 working ones. With a sloping acre to mow they have come in handy. :-)
