OutdoorKing Repair Forum Forums Repairs and Maintenance Questions On Ride On Mowers Questions On Victa Ride On Mower Frames Victa 4012GXT

I agree Bruce, any major leak from the cylinder into the intake manifold could do it. Anything involving valves, seats or camshaft is likely to show up if he checks the compression. The B&S 'Easy Spin' feature makes this a bit more difficult to investigate, but only a bit.

So far I have removed the muffler and run it with no noticable difference. It turns out the muffler is brand new and still clean inside. The blue flame from the exhaust was pretty. The fuel tap was fitted backwards but was still allowing some fuel to flow through at a reduced rate. I noticed some rubbish had shown up in the float bowl after the run so I'm soaking the carb at the moment. It doesn't have a fuel filter which can't be good. I haven't done a proper compression test but it feels really good when turning it over by hand. Doesn't seem to be leaky.

I put it all back together and it has improved a bit. It's still not right though. The higher the revs the less surging although there is an uneven valve pop especially at the higher revs.

Roughly how far out from bottomed should the idle mixture screw be as a starting point? 1 1/2 turns?

I leave it to you to do the obvious things like get the free fuel flow out of the tank up to the correct rate and make sure the needle and seat is clear and not sticking. You can waste a lot of time if you ignore the routine stuff. My B&S repair manual does not refer to your engine specifically. It may have the same carburetor as the 253400 engines, which is a cross-over flow jet with integral fuel pump. The idle and high speed mixture needles stick up vertically from right above the venturi, the high speed one being directly above the center of the float bowl. The correct first guess adjustment for the idle mixture screw on that carburetor is one turn, compared with 1.5 turns for the high speed mixture screw. Make final idle mixture control at 1750 RPM by setting the screw halfway between too rich and too lean. The correct float level is checked by taking off the carburetor, removing the float bowl, turning the carburetor upside down, and observing whether the float sits exactly parallel to the bowl mounting surface. If it's not, don't try to fix it by just pushing on the float. Use some science - carefully bend the float tang with long-nose pliers.

Can I really bend the float tang of a plastic float? Sounds risky.

My carb is different from yours. It's a Walbro with only one mixture screw sticking out of the side.

The float is sitting higher than your description. I checked the plug and it was running long enough to start to show colour. It's going dark brown on the electrode tip so it doesn't seem to be too lean now.

Whoa, do not apply any flo-jet lore to a Walbro carburetor. Flo-jets have brass floats, and many other differences. I have no information on new-fangled carburetors.

Do you have a fuel pump or gravity feed?

Some engine problems come from dirt and lack of use, and go away after running for a while.

it's just gravity feed and it's flowing well now that the fuel tap is around the right way.

If the carburetor is now clean, including the fuel hose and the needle & seat, there is no more crud in the bottom of the fuel tank, and the engine runs better and better as you run it more, the possibility exists that the original problem is going away. Might have been dirt in the fuel system. Might have been corrosion on the inlet valve or its seat if it's been ridden hard and put up wet. Personally I'd check the ignition timing, and the condition of the points as well if it has any, because you know this engine has been abused by an amateur.

Bruce, you said you have a workshop manual for this mower. Could you please upload any sections relevant to the work I'm doing at the moment? For instance...Walbro carb details and ignition timing stuff. Does this engine have points?


"because you know this engine has been abused by an amateur"

Hey! I resemble that remark.

I will try to upload within the next couple of days.

I could still use the Walbro info and the sections covering the valves and ignition.

It's running the best so far but still wanders a bit which activates the governor. The lower the revs, the worse it is. It's not showing lean when reading the plug. Valves appear to be popping a bit so maybe that's the problem.

I have uploaded engine information into the parts list and manuals area for lawn mowers.

Thanks Bruce.

Paul_S,

Let us know if you need more information uploaded because once it is up there it stays there for the use of all members of the forum that subscribe.

Hey Bruce, do you have any idea what model Murray would be the same as the VRO 40-12 GXT? I contacted Murray in the U.S. and they can't help as Briggs & Stratton bought their liquidated assets aswell and can't find a record of the Victa.
I was hoping to be able to buy Murray equivalent parts. The local Murray dealer up here can't (or won't) help.

I think I may have found something very close. The Murray 40508X92G.

The model should be a 40503x88A.

Thanks Bruce. The Murray website doesn't have the owners manual or parts list for that model as a download although the parts would be the same from the 40508X92G.

I got it going and did a mow with it. The engine still wanders a bit when off load and it always stops with a backfire when I shut it down. It won't start using the ignition switch so I'll have to go through the wiring and check to see if the solenoid is ok.

Did you check the flywheel key. As to the owners manual I have uploaded the one for the Victa.

All you need to do is quote the numbers that you want and we can supply Murray parts.

Thanks Bruce. Good to know.

I haven't checked the flywheel key yet but I will.

If the flywheel key is OK the ignition timing can't be all that far out. If you have electronic ignition plus the key is OK, it can't be out at all. Personally I think I'd rather use an ordinary automotive timing light so I can check everything at once, but then the first time you do it you have to mark top dead center on the outside of the flywheel. I just hate taking the flywheel retaining nut off to get a look at the key - and anyway I got in the habit of using a timing light.

The flywheel is in a fixed position providing the key is not damaged at all. Most engines these days have a fixed position for the flywheel and the key is alloy which sometimes gets damaged slightly and throws the timing out.

If you were working on an old villiers it is a different story where you need the top dead centre setting for the timing as the flywheel is on a tapper.

Bruce, you make a good point. My timing marks on the flywheel only show TDC correctly if the flywheel is in the right place. If the key is sheared the spark will still happen in the right place on the flywheel, even though the crankshaft is in the wrong place. I've just been lucky I haven't used my method on an engine that actually had a sheared key. It's OK for detecting the wrong breaker gap, at least.

With regard to those old Villiers engines with no flywheel key, when I didn't even know what the breaker gap was supposed to be it was a trial and error job for me. Took me a couple of hours to get a reasonable result on my old Atco. It would be really difficult to sell me one of those Villiers if I had a choice of a Briggs & Stratton.

Do you have any idea which engine the mower would have come with and if there's a difference in the shaft lengths between the black engine and the red one? It has a red one fitted to it now. I've raised the engine on spacers 9mm and it looks like I'll have to raise it another 6-7mm to get the motion drive belt to stop rubbing on the chassis. Maybe it had the black engine and there's a difference. This stack pulley doesn't seem right for this engine.

Paul_S,

You would need the model type and code to work out the difference between the motors really as the shaft length and diameter could be different.

I have raised it 16mm now. It's still not high enough and the bonnet doesn't want to close. I suspect the engine that was originally fitted had a shaft an inch shorter than the one on this engine. It looks like I'm up for another stack pulley. How much will one cost?

Paul_S,

You can cut the shaft as they usually have the key way most of the way and if they have a half moon key then they have two.

Are you talking about cutting the crankshaft or the stack pulley?

The crankshaft

Can you just push the pulley further up the shaft and leave the crankshaft sticking out an inch below the pulley? If necessary you could drill and tap the pulley for a grubscrew to retain it.

Paul, Briggs & Stratton have two standard shaft lengths on most of their engines (including the mid-sized ones), measured from the engine mounting flange to the drive flange. The shorter one is usually about 62 mm and the longer one about 80 mm, though the best I've been able to do measuring my Victa shaft gave me 87 mm. You could look this up on the internet to try to get accurate figures for your engine, but if it is about 80 mm or so, you have a long-shaft engine. Remember to measure from the engine mounting flange, not the oil seal where the shaft comes out of the sump.