My first time running an aftermarket CDI on a bike/moped. I've the budget Puch CDI from Treats. The alignment holes in the stator will not get me close on time. I figured I could just rotate the rotor instead of the stator to set the time that way, but it doesn't seem to be working as I'd hoped. I'll turn the rotor and the timing will either stay in the same spot, or go way out (e.g. 100 degrees). Maybe my theory about turning the rotor is incorrect? Anyone have thoughts on this? (edited)
Four score and seven years ago I elongated the stator slots enough to get the proper timing....
Like Bob says, dremel the stator slots to give you more adjustment.
It's not possible for what I need to do. Bolted up any way I can the timing is out ~100 degrees. There are coils in the way and on part of the stator there is no metal where a bolt hole would need to go. The only option would be to build a new stator plate if I cannot just turn the stator to correct the timing. (edited)
Then something is installed wrong or defective, or you got the wrong one. ZA50 perhaps.
It's a Laura M48 bottom end with a Tomos A55 crankshaft and custom cylinder. The puch stator plate fits the Batavus bolt hole pattern, but the timing needs to be completely different. Right now I am trying to test a few things before probably buying a programmable HPI (I am still researching this). I just want to make sure the thing will run OK under it's own power before throwing more money at it. Trying to get the timing in around 18-20 degrees advance static any way I can for the time being so I can decide where to go next. Hence why I have been fiddling with the rotor position as a temporary solution. Does anyone know if this is possible?
Damn it would have been nice to preface that frankenbuild in the beginning of the thread, before people assume your Puch stator is going on... a Puch. Ya think?
Pull the flywheel key, get a timing tool, a degree wheel, and start clocking it. (edited)
DPC Ryan, I understand your point, though put unnecessarily harshly.
I figured out what the problem was. I was looking at a mark on the rotor and expecting it to move position rotationally under the timing light when I shifted its position relative to the crankshaft. I should have been simply moving the crankshaft, relative to the rotor, to the right spot with respect to the timing mark that stayed in the same spot under the timing light.
I just expected that someone capable of matching those parts together would have an understanding of the concepts that they operate under. You figured it out.
Yeah, Ryan quit being harsh on Frankenstein there. ....lolz
I would recommend just getting an hpi. then it doesn't matter where the woodruff key is at, since you don't use one. Get a timing light, find out where its sparking, set your piston to the right spot, put it together with some retaining compound, without a key and hope for the best.
With an HPI you don't need a timing light. The marks already exist for you. You just need to set the piston position and align the predetermined marks. A light could be used to confirm that it is working but isn't necessary to get it going in the first place.
In his case, with no preexisting marks it will need a light to identify where it fires.
I will get an HPI if I can see these components run together for a bit. The programmable version of the HPI looks interesting and potentially very helpful for what I'm trying to do, but I need to look into it further. There are enough things on this motor that I'm not entirely sure will work, hence why I'm messing with this Puch CDI for the moment. I got it timed in last night and fired for a second. It didn't stay running though, and upon inspection it appears the rotor spun on the crankshaft. Will try again tonight after super gluing the rotor in position to see if that holds it steady to run long enough to give me enough confidence to put some more money into it. (edited)
Use lapping compound. The programmable HPI will be a waste of money for most setups. The programmable function of it will not make setting your timing easier, it only controls the curve.
a55 crank inside a m48? i'm paying attention.
can you elaborate on this "custom cylinder"?
what did you do with the tiny batavus intake?
you should do a build thread
I fired it up last night with superglue holding the flywheel steady and had it run for awhile. The large Puch flywheel runs close to the Bat case and started rubbing causing the motor to stop. Flywheel had been machined down as far as possible so it's not gonna work. Ordered HPI mini-rotor last night. That should solve the interference issue and make for a better CDI overall.
DPC Ryan Wrote:
-------------------------------------------------------
> Use lapping compound. The programmable HPI will be
> a waste of money for most setups. The programmable
> function of it will not make setting your timing
> easier, it only controls the curve.
I am researching it with the intention to program the curves. I've no problem setting timing, aside from the lapse of thinking that caused this thread to be started. Lapping compound? Is the idea that the grit will cause enough friction to lock it in place? I would fear that if the flywheel did break loose it would destroy the taper interface very quickly. If you've not used super glue I'd try it. Used lots in machining for temporary holds on parts. Releases from heat from a propane torch, heat gun, etc. Don't breathe in the dissipated vapors though. Gnarly stuff.
I'm planning on pushing this motor right to the edge, with peak power happening ~12k RPM, so it would be nice to tweak the curve all along the way to maximum temperatures/performance instead of relying on a preset curve to get there. Might get lucky though. Will see how the stock HPI curves perform. (edited)
No, lapping compound is used to lap valves to the valve seat. It is a fine grinding compound that is used to remove the imperfections and differences between two faces so that they fit together as completely as possible. By lapping the taper of the crank with the flywheel you will have more "grip" because the surfaces will be matched together. You don't leave the compound in like a glue. Another option is Loctite "green", bearing retainer compound. (edited)
Ah, gotchya. That makes more sense.
Don't use retaining compound, it will gum up your crankshaft over the long term and your timing will slip.
Do lap the flywheel to the crank for a better hold before installing for good, however.
Want to post in this forum? We'd love to have you join the discussion, but first: