OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Some help with an over revving Victa Powertorque.

Hi guys, I hope you don't mind me bombing in here looking for help.

I've picked up a 93' power torque Victa that's over revving and doesn't idle. I know this is a fairly common issue and I've looked at all the common fixes.
I've checked the carb manifold o rings and the top case o ring, they seem to be in very good condition. I've pulled the carb apart and found two brass washers under the governor. I couldn't say if they were installed as a last ditch effort to get this thing to run or if they've been there for ever. Regardless, they're in there. I read here and on other forums that there is rarely a need for more than two washers.
If I squash the rubber inlet hose the mower calms down. So, an airleak seems to be the problem.
The only seal I haven't eyeballed is the lower crank seal, under the flywheel.
I thought I'd ask for a second opinion before I went pulling the rod, piston and crank out to possibly find a perfectly good seal.
I also haven't looked at the vacuume decomp, other than to suck on the hose to confirm that the valve closes. It does. Can this be blanked off to test?

Oh, this mower is for a kid in my street who wants to try making a few bucks after school mowing lawns. I only paid $15 for it and other than being covered in dirt it's in really quite good condition. I'd like to get it running nicely, no point in giving this kid a dud gift.

Really appreciate any help.

Hi StotheH, and welcome to the forum. You've come to the right place for help and advice. Sounds like you've got the basics down pat.
You can blank off the decomp valve very easily by removing it and and replacing it with an old CJ8 spark plug.
I have 2 points i'd like to bring up, 1)which "inlet hose" are you squashing which causes the mower to calm down. 2)have you checked the governor diaphragm is seated correctly, you can do this by sucking on the hose that goes to the diaphragm cap.
A couple of pics of the carby area will help to identify if any of the hoses are misplaced.
Cheers, Ted

When you come up with an answer I know of a couple of blokes who would dearly love to know the fix, until then it is just a complete guess

Hi StotheH and as Bigted said
If you have sucked on the decompression valve and it moved in and out as it should I'd say that it's working.Removing it would only help to up the revs even more.As they are installed not only to help control the revs but to also make it easier to start.It helps to stop a 2 stroke from kicking back and boy can that hurt.
As Bigted said the diaphragm in the carby could well be the issue.
What I'm trying to work out is why does it have 2 brass washers.I've only ever found brass washers in a G4 carby not an LM,but that's only from what I've found.The fact there there is two makes me think it's had some problem before.
Something else I've found recently on a couple that I've had here is the two vacuum hoses to the carby being around the wrong,it doesn't make a huge difference but it did slow them down in rpm as well.
I think it was the one coming from the engine block to the top of the carby and the hose on the inlet side (bottom of carby) goes to the decompression valve.
The two I had were around the other way and they weren't running quite right until I turn them around the other way.I guess there is couple of things to look at see how you go.
Once again

Decomp valve is obviously working fine because it is running but over revving, what we need to know is how to control the revs, and that is the burning question

I pulled the decomp today and bunged it with a plug but yeah, no difference. I might try pulling those two washers out, just to make sure they're not causing any odd behaviour. I guess a set of o-rings couldn't hurt either. Maybe some three-bond first.

trust me "O" rings won't help, been there done that, we also had one with 2 washers in it and removing those did nothing, in or out, no difference. We have done the new springs,diaphram, poppets, nothing solves the throttle control, flat out or stop

Well, SOB, that sucks! I mean, it'll mow a lawn, I just hate getting beat by two strokes!

I should mention that it starts like a dream. Which makes an airleak seem less likely.

Anyone tried an ultrasonic cleaner on one of these problem carbs? Are there any internal fuel passages that could get gummed up?

I'm hearing you brother, it hurts being beaten by a bit of plastic rubbish. Ultrasonic won't help, I can't see anything it would clean, seems to me the slide does nothing with the air control. Where in Aus are you,trying to get a group together in Melb to have Sunday afternoon think tanks on what makes these LM carbs not work,we can sit around a table having tea and biscuits discussing them before smashing them with a hammer

What I have found is that sucking or blowing in the governor tube will raise or lower the revs, the throttle control does nothing, so this to me indicates the problem is inside the crankcase, does anybody know what controls this inside the case? The one Bumps is working on, he has the hose coming up to the fan on top of the motor. He is working with, I think a full crank motor he has adapted to use an LM carb. I'm working on a number of Powertorque motors

hi slotheH,
Try anothe carbouretta on that engine and that carb on another engine, .to help find where the problem is.
speedy

Speedy, I wish it was just that simple

The governor is connected to the vacuum button on the crankcase. It is basically a small hole with a vane, vacuum is created by the spinning flywheel pulling air away from the button. Blow through the hose going to the button it should be clear/unblocked, if this is ok check it is tight against the block and located correctly by the dowel/pin. If you are still getting no vacuum to the governor then you have a vacuum leak. Don't assume anything looks ok, replace the starter and inlet manifold orings with genuine victa orings. Be thorough and clean with your carb re-assembbly, before you refit the top spring, set the throttle to to the idle position and check there is virtually no movement in the poppet valve ie it is almost completely closed. I have not yet experienced a lower crank seal leak, or leak from the starter itself.

Other potential leaks may occur from the decompressor not sealing ie buildup on the valve head, this can be checked by removing it or simply sucking on a bit of hose attached to the decompressor and try to turn the engine over. In very rare cases there has been tiny cracsk in the carb body itself

Dan, I usually remove the decomp as a first port of call, to prove or disprove this potential problem. Playing with about 10 carbs means having a cracked carb is a low chance. Sure I have some carbs that just don't work so I move on to another one. Bumps has one that is working perfectly, but he is reluctant to pull it off for investigation in case it never works again and more importantly it is his wifes mower. Words have been uttered that go something like this "don't you touch my mower"

StotheH I now have a fix for these over revving motors, it will give you a slow tick over at idle to full revs with full control and a perfectly smooth operation. If you want to send me the cam and the end cap from your carby I will modify them and send them back to you for the cost of the return postage. This goes for anybody else here at ODK.