Printable View
Having trouble with the mower not cutting off,have to turn the fuel off and wait till it stops.
As I am not sure what to do ,,I will ask here.
I wish to make a kill switch that I can use to instantly stop the motor.
I dont feel I should cut the spark plug lead to fit the switch,can someone give me some basic tips on what I need to do ,wiring diagram etc.
Thank you.
Steve
Dear Steve,
Not sure we're in the best forum for this, but there's a little wire that's connected to (or at least supposed to be) the butterfly-valve swivel at the bottom end of the throttle cable. It has to earth on the chassis for the motor to turn off, which it does when the throttle lever is pulled (or pushed depending on the model) all the way to "Stop". It's probably just worked itself loose off the swivel. Have a look down there for a loose wire, and see what you find. If you want to test the mower, start her up, and just pull the spark-plug lead off to kill it (might be a good idea to wear some rubber gloves while you're doing it...). Has the problem just started suddenly, or has it been building up?
Good Luck,
Batpig.
P.S. I might go out and have a look at mine a little later on to get a more exact idea of the proper setup with the wire Steve.
Stick a screwdriver under the insulated to over the spark plug. That is the screwdriver blade touching the top of the spark plug. Then touch the side of the screwdriver blade on the metal surround of the petrol tank or any other "earth" It will stop pretty quickly.
Did this on my mower for years.
This should be an easy fix, just need a photo of the mower and the carby. :2tsup:
Batpig is on the money. I just cut that little black wire and put a push button switch in it and because I can't tell whether it is on or off I just press it until the motor stops and then press it again so it is ready to go next time.
just pull teh wire off the spark plug when u want it to stop.
or put a switch on the plug wire. thats what id do.:2tsup:
Don't pull the plug lead off!
The energy stored in the ignition coil has to go somewhere - and removing the lead will probably result in the coil breaking down internally (and it'll shorten the life of the coil).
Short the plug out if you have to - but I'd suggest bringing a grounded screwdriver up to the plug (not the other way around) as this help prevent an accidental kick from the coil. it might also help to keep the sparking away from the metal surround of the petrol tank :wink:
I think the best advice is to go with Batpig's advice.
Managed to get a couple of photos to assist my enquiry and any replies.
looks like a wire comes from the right side of the mag to the carby underneath side,the other right side wire goes up and under the cowling to a coil type thingy..
Another wire exits the mag and goes to a plug in type brass prong that also goes into the carby.
Any assistance is welcome as I dont wish to cut the wrong wires.
I wish to fit a switch that I will press in untill the engine stops and then it is right to when required next.
Cheers.
Steve
I had a similar problem with my Victa mower recently. It wouldn't start.
I ended up replacing all the perished rubber bits on the carby and one of those was the rubber boot where the two wire enter the carby. The boot had degraded to the point where it no longer kept the wires apart.
Dear Steve,
I'm figuring that must be one of Victa's own 2-strokes, because I've certainly never seen a motor like it before. Is there any chance of taking the cowling off to reveal the throttle-cable linkage in the carb, and increasing the resolution on your camera before you take another photo or two?..
Best Wishes,
Batpig.
I rebuilt our ancient old "wind-up" Vic' with a 2nd-hand Racing Go-Kart motor. (Which originally came from an even older "pulley-start" Vic'. :rolleyes:)
It needed a decompressor to start and idled at too high a rev to be killed by throttling back. So I simply cut a strip out of some galv iron I had lying around and bolted it to the head. Whenever I wanted to stop the mower, I simply nudged the strip with my toe so it shorted out the plug. :D
Bloody good mower, that. Wish I still had it!
I had to reduce the resolution of the photos to get them on the list,.When I took them they looked great but the list only accepts 100k or less ,thus the reduction in quality
The throttle cable passes through the air intake tube that you see in the photo.
It appears to be an original Victa engine (2Stroke type)..Not sure how old it is though
Motor is about 25 -30 YO as a guess. It is a transisional motor between the original double ended cranks and the later 160 cantelever crank units. For some reason they modified the cylinder casting and fitted the barrel valve carby for a year or so before going to the cantelever crank motor. With the cantelever crank motor, the flywheel and coil are below the level of the cylinder and behind the crankcase casting (not visible with engine mounted in mower base.
Within the guts of the carby, there is a barrel which controls the airflow to the motor. This is in the horizontal cylinder section in the OP's pics. As he mentioned, the throttle cable runs inside the snorkel tube. The cable causes the barrel to rotate to control the airflow and RPM.
The two wires with brass contacts (an earth and magneto coil low tension) enter the carby and are kept seperated in flexible mounts. When the throttle control is at the STOP position, a cam lobe on the throttle barrel pushes on the contacts together to short the magneto primary winding, so that the secondary winding cannot produce a spark, stopping the motor.
It is possible to bypass this system and fit an external kill switch by removing the cables from the carby and wiring them through a push on (Normally Open) momentary switch. I did this to cure the same poblem about 20 years ago using a redundant switch from an add on windscreen washer system from a car.
If you do do this, ensure that the openings where the wires entered the carby are properly plugged to avoid dusty air getting in through the holes.
You can't fit a switch in the plug lead, as the 25000V spark voltage would jump the contact gap in the switch when it was opened, and the motor would continue to run.
If you need more help look in your local library for a Gregory's Victa mower service manual. I had one for years but can't find it at the moment, suspect that it got pitched in a clean up a couple of months ago as I don't have any Victa gear any more. I think a fair number of local libraries have had it in the past, ours has.
Thanks Malb,
You nailed it in one go,spot on diagnosis for my problem.
I slipped those two little brass probes out and connected to either side of my switch which is normally open.When I press and hold the button the motor stops instantly.
Have given the beast a new lease on life.
The photos probably dont show it,but I have the motor removed from the mower and mounted on a plate with a shroud that fits onto the top of my whiz bin.I left the mower plate on and bolted another cross blade and sharpenedit to a fine edge.I then cut a 80mm hole in the top plate and feed all my garden / shrub cuttings straight into the funnel that I fitted into the 80mm hole,works a treat ,you have to be a little patient on the 80mm stuff,cuts it fine when wet and sappy,dont think it would cut dry 80mm branches though.
Thanks again for your fine tips.I had no clue which one to remove or cut,glad I came to the forum to post my questions and queries.
Cheers.
Steve
That is superb stuff Malb. You are one clued-up-in-multiple-fields Son Of A Gun!.. :2tsup:
Happy endings are great, are they not?..:D
Best Wishes,
Batpig.