OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Victa Lawn Mower Frames Victa Vulcan 505 self prop mower runs too fast!

Hello All.
This is my first post. I was given the above mower about 3 years ago. The problem was that the mower just ran too fast and when the "clutch" was engaged it ran away with me! (I know it isn't a proper clutch!). I just left it outside in the weather. A week or so ago I decided to use a mower with a permanent scarifier blade fixed to it. The Vulcan was my choice. After a Marathon free up (water had got in and it was a mess!). Finally got it back together and it started first pull!!! But same problem I can't get it to slow down sufficiently. The carb has been stripped cleaned and reassembled and nothing was amiss except oil where it should not be (didn't shut the fuel tap did I!).
There doesn't seem much in the carb (such as a slow running jet). So how do I slow it down?

Thanks,

Andrew.

I believe there is a small screw on the handle below the air filter that allows you to adjust the speed of the engine.

I could be terribly wrong though... I am A Briggs And Stratton Mechanic, not a Victa one.

Kori

Is the motor overrevving or the self propelled too fast?

Hello,
Just realised that I posted this in the wrong place! Sorry!
The mower is simply running too fast and hence the run away when you engage the clutch! You can just about get a reasonable speed before the cut off switch in the carb operates. hence the slightest bump and the mower either stops or shoots off! Unlike most other mowers, there doesn't seem to be a adjustable mixture jet or adjustable slow running jet. So unless you change the timing I am stumped. The carb is clean and assembled in the correct manner. The diaphragm is in good shape. I do like this Victa. They are built like a tank, I just love the big end bearing! This particular Victa has a cast alloy deck and it should last forever. If only I can slow it down a little,
Any help would be much appreciated,

Andrew.

G'day Andrew,
Your engine is a power torque 160cc?
The hose from block to the back of the carby is meant to provide a vacuum to control overspeed (vacuum vs spring pressure governer)

The self propelled operating lever up on the handles can be adjusted.
You can loosen the cable by undoing the 2 x 10mm nuts half way down the bars.

Hello Mark, Thanks for your suggestions, The "clutch" is just an idler wheel which is used to push on the drive belt and hence make it bear on the drive wheelto the rear wheel drive. As far as I can fathom this idler wheel should be either fully in or out. Surely it is bad engineering practice to allow the drive belt to partially slip to achieve different speeds?
The real problem is that the engine is over reving. I am afraid I don't know which block it is looks about 100cc by eye, but could be 160cc! There is a solid metal casting that mounts the carb to the block, not a hose. As far as balancing out vacuum against spring pressure via the diaphragm is concerned. I am stumped. The diaphragm doesn't seem to be connected to anything so I don't know how the diaphragm position controls the engine speed. Would you like to explain that one in a bit ore detail mark? Not being a smart a*$e here! I genuinely can't understand that one!

Thanks for trying to help,

Andrew.

Hello Andrew,
There should be a black hose going from the back of the carby to the vacuum nozzle on the cast iron block.

Poke a piece of wire like a paper clip through its hole, to make sure it is clear.

Also, if the diaphragm is sealed properly, you should not be able to suck or blow through the black tube connecting to the back of the carby. (diaphragm end) This is a test you can do.

The flywheels fan will create a vacuum through this hole and connecting tube & on the back of the diaphragm, this fights against spring pressure in the carby, whch makes the poppet valve open & close to give more or less fuel depending on load.
Hope this helps.

Hello Mark,
Been busy tidying up because daughter is coming back from Oz for a 3 week holiday. I will try out your suggestions in the next day or two and report back. I have had a lot of rust damage including a bit to the bore Argh! but all this has been cleaned up and starting is no problem. Must look out for a new block at some stage as this is one solid mower and deserves some attention. None of this has caused the problem as it was running too fast from the word go, and the water ingress happened when it was dumped in a corner of the garden!

Regards,

Andrew.

My limited understanding is that the o rings from carb to "manifold" and "manifold" to cylinder can cause over rev if they are leaking. May be worth replacing them as they can deteriorate over time and cause an overly lean mixture.
Chris

Hi Chris, good thoughts there mate, he might also check the 'O'ring under the starter...Power-Torques are renowned for that prob.