If you do get super bored you only need to bring the black wire up from the carby inside the snorkel tube and you can set it up so that when you pull the throttle back to the stop position the lever contacts the wire and earths the ignition out as it is earthed to the handle already
I had a carby that I modified yesterday that I could not get to come back to idle. I had fitted 5 washers under the cam , this was reducing it but it was still way to high. Got another carby body, swapped all the internals, 3 washers under the cam and it works perfectly. Out of all the carbs I have modified I only have 3 bodies that won't work for some reason, the one yesterday an 2 previous ones that would not start. Remove the internals to another body and no problems. Why I have no idea
^ air must be seeping in somehow. Probably requires examination with a sophisticated scanner of some sort to find it. Fortunately it doesn't often afflict them and there are still tonnes of the things around. Into Mr Sulo with them.
Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
I was doing a later PT the other week (Chinese block) had the exact same problem. Changed the carby body, then no issues. I noted that the cam was easy to turn part of the way, but became harder as it went back to what would be the idle position, then became easy as it went back to the cold start and stop position.
It was as though the cam 'legs' were snagging up on the carby body (maybe the plastic had age expanded), then suddenly letting go. Perhaps with the lifter, and diaphragm with springs, the resistance meant the throttle cable just twisted/moved in the snorkel without changing cam position in these difficult spots.
How fast do you think he'll burn out his bearings? :-/
Don't get me wrong, the modification looks awesome, and kudos to them for getting it done.
I just see the mower overheating, wearing parts, etc. But it'd be a fun project... how much power can you get from your PowerTorque?! I'd enter that contest... haha :-)
That is not overworking a Victa 2 stroke, they are easily capable of that work, be a bit better if it had the fan shroud to get some cooling over the motor. Also the motor does not have a lot of compression because as you can see when starting it shows little resistance on when he pulls on it without a decomp valve in it. The other thing that will kill it is the use of a pod filter down there, they are only good for keeping out rocks and quails. Another thing that makes it a lot easier on the motor when chewing through that sort of grass is having the rear flap lifted a bit so the grass can be ejected out, not getting bound up inside the mower. Then the will really get through that stuff easily
Just as an update on the carby mods I am no longer fitting the external kill switch, on probably the last 10 I have done I run a wire up the inside of the snorkel and use the throttle stop screw I fit to earth the ignition out, much better idea
I'm doing one right now but it is a bit hard to take a pic while I am doing it and at the end there is nothing much to see. I drill a 1/8th inch hole in the underside of the rubber hose near the carby, feed the wire up the inside, drill another 1/8th hole just below where the throttle cable goes into the filter chamber and the wire is connected to the button head screw I use in the throttle stop. This is how Victa should have done it in the first place and not used that abomination of their long lunch, we are smarter than the rest of the world, kill switch.
That is a better idea. I will go that way on the next one whenever that is. I'm just about Victa'd out at the moment after finishing the 24.
Its hard to get a durable kill switch at a reasonable price. I have been using an ATV/motorcycle/gokart kill switch. Its about $5.00. It looks durable but I have to remark the "Stop" & "Run" signs on it and its easy to try to start without switching to run and then of course nothing happens.I also have to remark the throttle with a "Start" at the "Run" position and "Idle" at the other end.Otherwise my machanically challenged extended family can not get them to go. By the way I also have to put "Oil" pn the fuel cap and highlight the 25:! words as well. The other day I got a call that one would not go. Trying to start at trhe Idle position of course but just as well it would not go, the tank was filled with straight petrol. All the best Jeff
MF, the screw is just a button head screw, I use those because they have a big head and won't fall through the slot. I cut a small square piece of metal for the inside so the screw can sandwich the wire eyelet between it and the plastic housing. The wire that needs connecting is the black wire, I just cut the other one off
I just did the mod today on the old G4 someone fitted to the PT I was given - and it gave all the symptoms of the one you mentioned last september - sometimes rev, sometimes stall if not throttle not flicked, then occasionally revs its guts out.
With 3 washers under the cam, the cable ball wont engage properly in the cam, with 2 it works alright but the lowest idle I can get is 1500 rpm (on tach).
Going to change the body and see how it goes - but its 40 degrees tomorrow so probably will be inside
Hi Tyler, yes I know the 3 washers can give problems getting the ball to fit which is why I only clip the cable in the first slot, if you try getting it into the second slot you end up kinking the cable. If only Victa had extended the top of the cam instead of putting the hump on it the washers would not have been needed and an idle could have been achieved easily. On a couple I have had to fit 4 washers to get the idle to come down enough so I could adjust it with the screw but it is very rare, 3 is usually the right amount
I will try removing the cable and only latching it in one latch (then adjusting the screw on the air filter housing as it will probably be a bit out) - I guess it allows it to pivot a bit and not kink.
It was quite strange how the behaviour kept changing - it was smoking badly at one point and went through 1/2 a tank in 10-15 minutes
Flat stick, I was getting 3600 rpm, but couldn't get a good idle unless I took the long spring out (was playing around at one point trying to see what was wrong)
Hi Tyler, another thing I started doing ages ago was to just cut the big spring in half, sometimes I just use one half on the lifter and the other half under the cap, either method seems to work fine and by cutting the big spring in half it reduces the pressure on all the bits in there and and puts less pressure on the cable so using the first notch isn't a problem
I am pretty sure there is something wrong with the carby body. Even tried a lm cam, better but not great and of course the stop position was miles off.
When I put the cable in one notch, it wouldn't completely pull back to the stop position
Without the big spring, idled great but wouldn't rev - might try cutting the spring thanks
I am going to put a LM as it is really annoying me
It does happen Tyler, I have had a few bodies that wouldn't work, swap everything to another body and they work fine. I know what you mean about annoying
Ok Something isn't right. I grabbed a LM body, used a different diaphragm, different primer cap, different needles, checked the decomp for carbon, put in a cj8 and tested, tried different combos of washers, cleaned jet, checked starter o ring, changed inlet o rings, checked fuel flow and it all made absolutely no bloody difference
If I hold the diaphragm back (with cap off) it will idle to the point of stalling
Next steps are ripping a carby off one of my other ones and putting a good known carby on it or cut the spring
I reckon its a governing issue - sometimes if I blew into the governor port on the cap, there was a air leak, I managed to get a great seal, but the cable is snagging (must be slightly warped) so will have to remove a washer. Ran out of time tonight - legal noise restriction 7pm
Both the cams I was trying with were the short legged versions - one seemed to cause the stop pins to actuate a lot lower down on the throttle control
Hi Tyler, It is something you are doing or not doing. I have never had 2 carbs in a row that cause me problems. I might get a problematic one in 50 I modify, usually everyone is just set and forget
Hi Tyler, you are a few years behind me with that idea, I tried extending the cam ramp but I was unable to get anything to hold to the cam because it also gets petrol in there and all the bits I glued in just eventually let go. If you could achieve that it means you could use the original kill switch idea which would save me a lot of work but at this stage I have not been able find any suitable way to extend the ramp. I sure hope you can come up with a method because that also removes the need for the washers under the cam. I had thought about trying to get new cams made but they would probably want an order of a min of 5000 or something like that. Keep trying as I am hoping you come up with an answer
