Hi Guys, After the successful designed and implemention of the new Victa metal needle with viton tip, I understand that we have some issue with sticking needle in somehow. This is very common to rubber tip needle. Unfortunately Victa design doesn't have the metering lever or hook to release the valve when fuel reservoir is nearly empty. To address this issue, I come up with using a conical compression spring placed in between the seat and the needle. This will allows the needle to released when float drops or when fuel reservoir is empty. But I need to balance the compression enough to release the valve and also not to add too much tension the float with negligible effect to the voyance. I attach the propose design for manufacturing. I welcome any thoughts especially from Norm K.
Hi carbymaster, it would have to be such a small spring and it would be such a balancing act to get it right. In all fairness the failure rate is probably about 10%, which is very annoying at the time, and much worse if somebody has only bought one and they still can't get it to work. At least I am able to swap needles and primer caps and eventually they work fine. As for the spring I appreciate what you are doing but it may just complicate matters with the needle not shutting and flooding the crank, and this can happen in the blink of an eye. The next question that needs to be asked is how many more full cranks and Powertorques are going to be salvaged and who apart from the few of us here are trying to save the last of them. Sure people will keep buying needles and bits for them but the number seem to be starting to dry up. The other issue with the float needle is that the average Joe Blow puts in a new needle and because of the design of the carby it is impossible for him to know if the needle is sticking or not so they give up
I'm not sure about the spring either. It could easily cause more problems then it fixes.
Both the needles and primer caps I bought from Carbymaster now work perfectly even though in both cases they seemed to stick when brand new and viewed on the bench not in a carby. I think the presence of fuel might harden the rubber slightly and of course in a carby there is a small head of fuel above. One thng I have found useful is to use the transparent yellow fuel hose. When all is good you can see the bubbles move then stop when the fuel is turned on. If they keep moving you have a flooding problem or if they do not move at all its sticking. A bit much for average Joe Blow I suppose.
I think Carbymaster should be applauded for his perseverence and ingenuity so far.
Hi Jeff about 50 % of the ones I fit stick in the seat when trying them for float clearance and most work fine, I know one mower I sold I went back there 3 times in 3 days to replace the primer cap and needles and that was after it had had a new primer cap and needle to start with. Haven't heard from him for 6 months now so it should be settled down now. I had a bad run on them for a few weeks but then it settled down again, not that I am doing many at the moment and we are heading into winter now. Yes I would have given up on the 2 strokes if I had had to continue trying to get those useless plastic needles to work
One thing I once did one one of mine was to install the primer plate so the horizontal line was slightly off horizontal. That is, make the line horizontal like normal, then turn very slightly anticlockwise. not sure if it was the slight angle that made the needle not stick (gravity pulling it slightly sideways then down) or if I was lucky. Ran as normal. I didn't want to go the other way (clockwise) as It might lower float level too much.
The other thing I was thinking of a few months ago was a bit of valve lapping compound on a cotton wool bud/q-tip and using an electric drill to spin the q tip. Maybe this would remove any metal swarf from the brass seat, or plastic swarf that might bind the sides.
Hi Tyler, yes I tried moving the primer cap forward and backwards in an attempt to get the needles to drop or to get them to shut off, anti clockwise to try and put a bit more pressure to close the needle off, and clockwise to try and get the needle to open, none of which made a lot of difference. Also tried the lapping compound bit more smoke and mirrors , rubbing the supposed rough sides off the needle, all pretty much useless. Regardless of whether I have a mower that is running well on a plastic needle, obviously an original Victa one, I throw them out and replace with a viton tipped one, just not worth the problem to me if they play up
Nice sharing you the idea but unfortunately after making the prototype, it's not successful as I thought. At the very minimum spring compression enough to release the sticky valve, it does reduce also the sealing ability of the valve from 5psi down to 3psi which I can observe bubble when the primer cap was submerged in the water with leak detector applied air pressure of 3psi. Conclusion is not a good approach. Please see attached photos of the prototype. Thanks Guys for all the thoughts.
Thanks for the effort carbymaster, much appreciated, we just have to live with some of the problems with these, just have to be very thankful that we have the viton tipped ones that have reduced the problem by 98%. It is one of the best improvements for the Victa 2 stroke ever. I believe probably 70 % of Victa 2 strokes have gone to an early grave due to faulty needles. 20% probably straight fueled and probably the remaining 10% just worn out, they too could have been repaired but cost prohibitive to any business trying to make money out of it. Different to us as we are conservationists just trying to save a species from extinction, see you can put a spin on anything.
Victa should have put a hook for the needle, like the new B&S black plastic carb that I was having rouble with for a while..... In the old days 2 strokes always had a hook of some sort with those metal floats... cheers speedy
........................Keep your blades sharp......................
I would say the spring is too extreme a measure for a problem that only afflicts some carburettors on occasion. You are compromising it's primary purpose : to form a seal. You would think the extra weight alone would ensure it releases.
Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
You have to give him points for trying MF, we are miles further ahead now with these needles, eventually every one of mine work as they should, just some cause a bit of grief and I can see no reason why. And now I am going back over the needles that have caused me problems and a number of them seem to work ok. Maybe being in and out of fuel over time has helped the tip settle
Finally I come up with solution and prototype to this sticky needle issue. I prefer not to change the design of the needle nor the quality of the Viton tip. The sealing ability of the current design is excellent and promising. Now we're only dealing with sticky needle. How to pull the needle when float drops without sacrificing the sealing quality? Looking on the existing design of the primer cap, I came with designing and making a "Needle Spring Lever". It's a combination of spring and a fork which attached to the float mount with a fork sliding though the needle crown. When the float drops, the float rear end will lever the spring and pulls the needles out while the fork is sliding through the needle crown. I have made a prototype made off a guitar string. Please see attached photos. I believe that his sort of design has never existed on any type of carburetors and I would like to welcome you to name this part. I would like to hear your thoughts and ideas. I will send this prototype to the manufacturer and to properly design the Needle Spring Lever. Thanks for all your thoughts and ideas.
Absolutely BRILLIANT but my big concern is the numbers you will be able to sell to offset the costs, who knows how long this 2 stroke world can/will continue
Why not offer as an optional extra for the event of a suspected sticking needle or as a solution to it occurring? What about developing a transparent primer cap or one with a viewing window to the needle and seat?
Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
Based on my experience I just do not think its needed. Some of those needles that seemed to stick when viewed outside a carby did not stick later after a bit of a fuel soak and in the carby with a very small head of fuel abpve it.
Norm,
How many have you had that caused an actual problem in use? My score is 0 out of 2. I thought most of yours were flooding. As I said before the transparent tube seems to help as you can see the bubbles move and then stop if all is OK.
Jeff I had one yesterday, one of the early viton tipped ones so probably near 18 months and just for some reason it decided it wouldn't play ball. What I tell people who can understand what I am saying is if it doesn't start, give the top of the carby a tap with a screwdriver handle and this usually makes the needle drop. Not sealing is a problem that seems to fluctuate, I get several in a row that play up then it seems to go away. Problem with the sticking is you can't see that it isn't working and the clear plastic tube is not too fuel friendly
MF on a mates 24,he was having problems with the needle sticking so I told him I would set up a small tac hammer on a pivot point and run a string up the handle bar so all he had to do was pull the string, hammer would hit the carby and it would shake the needle loose. He was so excited when he realized that a tap on the carby and he was up and running again. This one was stopping in the middle of a job and he was getting frustrated
