Dyna S and the Chinese copies

Recently I have had a few of the units (on a bike I sold) shed their magnet in the middle of a ride. Not good. You may expect it from the China  knockoffs but DynaS? Well we replaced the cheap China unit after it lost its magnet and replaced it with a Dyna S thinking that spending the additional $140 dollars would solve the problem!  WRONG! The Dyna S lost its magnet within 40 miles. Those magnets are just set in a pocket with some epoxy over the top. So I thought about it and decided there is a better way. So I drilled a pilot hole 180 degrees from the magnet and to the bottom of the magnet. I used a Dremel to remove the epoxy on top of the magnet and tapped out the magnet. From there I used a slightly smaller drill than the diameter of the magnet and drilled both sides. Then I used a drill the same size as the magnet and drilled through the original side where the magnet sat and to the other side stopping just short of the outside diameter. This created a lip that will hold the magnet in place once inserted. I filled the remainder of the holes with epoxy (original JB weld, 500 degrees). With a lip of a few thousands and epoxy behind it there is no way that will come out. So I will be doing this to all of the bikes with a China knockoff and maybe the ones with an original Dyna S. I have several bikes running the china units and several with original Dyna units but none of those magnets have spun off but do I want to take a chance. Anyway if you have a China unit you may want to think about doing this. Here are a few photo with the holes drilled and the magnet inserted before epoxy.

 

 

 

Are those Chinese knock-offs any good? I like the idea of not having a mechanical advancer but dont want to pay the expense of the dyna s because then id rather keep my bike the way it is now. These units remove the need for the igniter, correct? If so, id be interested in these Chinese knock-offs and perform what you have explained.

bound wrote:

Are those Chinese knock-offs any good? I like the idea of not having a mechanical advancer but dont want to pay the expense of the dyna s because then id rather keep my bike the way it is now. These units remove the need for the igniter, correct? If so, id be interested in these Chinese knock-offs and perform what you have explained.

It removes the igniter but you still need the mechanical advance mechanism

Well I have had very good luck with the China knockoffs. However when they first cam out I think they did a pretty good job with quality control but then the market was flooded with them and I purchased a couple that either had no magnet or was very week and would not trip the sensors. It seems like the higher priced ones ($50-$60 were ok but the cheaper ones under $50 were questionable. I think the main issue is that magnet. I put a China knock off on my KZ1100 due to a faulty ignitor using a mechanical advance from a Z1900 and it works fine. Murphys law has it that I sold one of my Z1900"s and it failed, then the Dyna failed. The guy was not happy so we are coverting back to points for him. Im pretty convinced my fix will solve that magnet issue. The sensors look identical to the Dyna, Dyna (called them and thats what they claim) says they are made in the US. Not so sure!. I have had several Dyna S units on a couple of my Z1 bikes for 14-16 years with no failures and several of the China units on other bikes with no failures other then what I mentioned above.

Wookie58 wrote:

bound wrote:

Are those Chinese knock-offs any good? I like the idea of not having a mechanical advancer but dont want to pay the expense of the dyna s because then id rather keep my bike the way it is now. These units remove the need for the igniter, correct? If so, id be interested in these Chinese knock-offs and perform what you have explained.

It removes the igniter but you still need the mechanical advance mechanism

Shucks! I must have it screwed in my head. I just really dont like the mechanical advancer so maybe I should look at a zn1100 or gpz1100 housing and pickups. If push comes to shove ill figure something out on my end. I just have a lot of problems and sometimes its hard to tell what problem is causing what!!!

Dyna changed the type of epoxy used to hold the magnets a few years ago which caused them to come loose so reverted back to the original and put out a recall to the dealers for the affected units.
Some had already been either sold or didn't get taken off the shelves so Dyna's policy is to replace them free of charge if they fail with this issue.
You just have to contact them and they will supply a new one.
As for the epoxy. I have modified a few rotors to re position the magnets and used Araldite epoxy to set them in with no issues but you could always put a light center pop or two on the outside of the hole to distort the edge and prevent the magnet coming out if it did work loose.
 

Ya I thought about putting a dimple on the outer edge to hold the magnet in place better but decided to ago this route. No way it's coming out. Its possible that those Dyna units were sitting on a shelf for two years and we happened to buy them! Either way Im surprised that Dyna has not devised a better way to mount those magnets.