OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Good day All

Hi,

Thanks Joe, I've managed to get some information on the unit and also a manual from Victa, the unit is a 160cc Mustang with an early version of LM carburettor. According to the serial number on the engine I'm guessing it's a 76 model. I did a compression test whilst cranking-over with a socket drive and was reading around 90 - 95 PSI, I've just stripped it back to give it a clean and a visual. Rings and bearings all look good, carby was given a clean and generally seems OK, I'll get back to it later if it needs further attention. Conducted several tests on the mangeto and there was no spark, so I 'flashed' it with 12V, still nothing, resolved that the coil has had-it. My only concern is the strengh of the magnets, although they still have a reasonable attraction, I'm not sure if they have weakened (or weakened too much). Is there a 'rule of thumb' for these or any way of testing... next question can they be removed and re-magnetising?

The best test of the adequacy of the strength of your magnets is whether they provide a blue spark when you turn the flywheel briskly with your hand (spark plug removed). I don't personally know of a flywheel type with removable magnets, and I doubt you could re-magnetise them very effectively in the flywheel. Make sure you remove all magnetic debris that attaches itself to the magnets.

Thanks, they certainly don't seem removable.... I'll check their operation once I recieve the new coil, condensor and HT lead....

Some progress, I received most of the parts and am getting a good spark so my main concerns with the magnet strength are put at ease. On the down-side I sheared the starter nut, so I'll be looking for a new one of these. Also noticed that the plastic carby is missing the large diaphram washer that supports the long outer spring, so I'll be looking for one of these as well. It is a similar plastic carby to that used with the power-torque motor, however it must be an earlier version as it doesn't have a primer bulb... looks like it has a small weep hole instead, (which I imagine is also missing a plug). I did take a couple of photos, although haven't got around to downloading them onto the PC.
As a result of this little exercise, I was also given another Victa mower by my Brother's friend, It's an early Commando style with a power torque engine... I had it running after a couple of minutes, although there appears to be some bottom-end noise...it will have to waite until I finish the first one.

Hi Mark T, and a big, warm welcome to the forum. It's great to have you aboard, because we all love to learn new things and tinker here.
It's good to see you are making good progress with your project and we're all looking forward to seeing your pics.
Photobucket is an excellent image host and is also a free download. Instructions on how to use it are in the "Help" topic...sub forum "How to use the forum features".

Once again

Hi Scott,

Thanks, I finally finished, (almost) reassembling the unit and ran it for the first time last night. Had some trouble with the pull-cord which was only partially engaging, I'll need to look into this. I used a rope around the starte cup (Drum) and this did the trick. Seemed to run OK, I'll need to look at some of the other things that are needed, like the pull cord etc...
Also a new decompressor, (currently an old spark-plug is being used to plug the hole). I have also managed to get some photos up on photobucket, unfortunately I always fail to take enough, you'll see that I already had the unit in pieces when the first shots were taken. I also hope these links work!!.

The base looks the same (including the colour) as my 1976 4 stroke, but mine has a warning label beside the VICTA identification, saying put your foot here before you start it. That would have been because of the vertical-pull starter on the old B&S - doesn't apply to the 2 stroke.

I have fixed up the pull-cord somewhat and ran it again. I noticed some intermittant clapping sound from the engine. I am guessing it's the piston clapping against the cylinder wall.
I will be taking the head off again to have a look.
If this is the case, wondering if I should bore and up-size the piston & rings? I've not done this before.

The piston would have to be pretty loose to be able to hear it when the engine is running. It happens with very sick and tired car engines, but those are a whole lot quieter than 2 stroke mower engines. I wonder of a loose big-end bearing isn't more likely? If the piston is loose in the bore you can usually move the piston around by putting your finger on top of it and pushing it from side to side. If it moves, it is due for replacement. For a 2 stroke Victa, I would expect a better piston and cylinder would be no further away than a nearby nature strip, so I wouldn't contemplate boring it - just scrounge up some better parts.
I doubt it is ever worthwhile doing base-engine work on a common model of 2 stroke Victa, just because you can usually get a better base engine for just about nothing. I think the usual cure is to gather up a decent base engine, then mix and match the rest of the parts until you have a complete engine in good order. However just for the fun of it you might just replace the piston and cylinder (with junked parts) if the rest of your engine is good. Be sure the big end and main bearings are good before you go to much trouble, though.

Did you replace the decompressor?

If so I would check the valve stem.

Hi Grumpy and Bruce,

Thankyou, I haven't replaced the decompressor yet, I'll feel around with the piston and will pull the head off if I feel this is the cause, then I will have to work back down to the crank. Ironically the bottom end seemed very good and tight, but then again it hadn't been run for some time... it was never going to be a financially viable project. I'll let you know when I get around to stripping it back down, thanks again.

Hi,

Also got around to playing with this unit again, checked piston movement and there wasn't any, also found the blade plate was a bit loose so I tightened this with the air-gun, turns out this was what was causing the noise . That'll learn me!
Anyway I had her up and running for a while and all else seems good, (at least I was right about the tightness of the bottom end, and saved me pulling it down again.... which is good). I'll need to get the starter pull-cord and spring back together and will be chasing parts on this (as soon as I get some free spend $$.

Thanks for the support... I'll keep you posted on the finished unit.

Wow, if the blade plate was loose there should have been some pretty serious vibration. Glad no harm was done.