Re: za50 crank shim advice/help in mass

Paz, It wasn't an issue with the crankshaft bearings. It was an issue with the clutch and starter plate spacing. He's having the issue with the 1977 crank and I've had the same issue with all the Treatland cranks. Ben explains his problem in this post:

"It was very hard to measure but it appeared that the spot on the crank that the spacer between the clutches sits on was roughly 1mm off from where it should have been. I had my crank shimmed so that my endfloat was correct but I was still sitting above that lip or whatever it is called do I then shimmed my flywheel side to try and compensate and there was no way of getting it to sit level with the splined piece so I just ended up grinding it down. When I measured it against my stock crank it was somewhat smaller but it was a big enough gap that it was not able to be compensated by shimming."

The problem with these aftermarket cranks is that the lip where the clutch spacer goes (see below picture) isn't high enough. I would love to talk with the manufacturer or 1977 or treats to fix the issue...

Re: za50 crank shim advice/help in mass

paz my crank is the one that had the stuffing fall out it should be on its way to you if not already there.

Re: za50 crank shim advice/help in mass

Ben n Wrote:


> paz my crank is the one that had the stuffing fall

> out it should be on its way to you if not already

> there.

That inspires confidence in the 1977 cranks... What happened Ben?

Re: za50 crank shim advice/help in mass

Just for reference both the 77 and treats cranks are from the exact same factory. 77 developed the crank with a factory in Taiwan, I actually still have the prototype in my 80 metro motor.

Regarding shimming on the clutch side of the transmission cover. The only thing that should makes a difference is the lip of the brass end piece. Since that is what the clutch bell rides on and you are shimming the spacing between the clutch bell and the bearing in the trans case.

Or am I missing something...

Ben yes received your crank the other day, thank you for shipping it. Have you received the brand new crank the warehouse shipped you as a replacment?

Honestly not sure why the stuffing failed, first time so hopefully it was a fluke.

Re: za50 crank shim advice/help in mass

Paz, nice to know they're the same product.

I know the float between the clutch bell matters and needs to be shimmed, but we're talking about the wrong dimensions of the crankshaft, causing the 2nd gear clutch to not spin freely. I can make a video if it helps.

Right now I would rather tell someone to have a connecting rod pressed in rather than buy the aftermarket unit due to this problem. BUT I would love to have the issue resolved with the manufacturer so it goes together much more smoothly.

Re: za50 crank shim advice/help in mass

paz i think the stuffing that failed was just a fluke and I got the new crank. Thank you,

The stuffing that failed was the one that had a burr still on the end of it so maybe it was just machined a little funky.

the picture that jake put up is the issue that I had it was like that the shim in between first and second gear would not sit on that shelf? it was too low.

My crank was spinning evenly and freely and did not bind on the starter clutch when I removed the shim between the starter clutch and the circ clip it spun better but still bound some because it was not low enough. now that i think about it maybe puch had slightly different tranny internals? because the issue could be coming from the splined part if the starter clutch that the second gear sits on or the height of the starter clutch. it could also be the height of the groove for the cir clip. its no big because i just took some off of the splined section and was good to go but it was a big amount could even be the bearings as I bought new ones. I literally tried everything for about two weeks to get it to fit and found that I was sitting about a millimeter above the shelf for the shim between the clutches. I went back and made sure all my races were all the way in and that I was shimmed correctly. I tried putting a .3m shim on the tranny side and could not close my case.

Paz if there are any measurements I could take that could help, Let me know because I just got back from vacation so I haven't slapped everything together yet. as for the history of my za I got it off of a kid that destroyed the crank so I have that sitting around to compare. (edited)

Re: za50 crank shim advice/help in mass

Glad you got the crank!

Wow I'm a moron sorry I though you were talking about something else entirely. That little issue with the 2nd speed clutch binding up is something that I know about, just kind of forgot until I realized what you were referring to.

It has popped up on about 3 of the builds I have done with that crank, and none of the recent ones hence why it slipped my mind.

It's a minor error in the companies machining of the cir-clip grove. The cir-grove is cut one clip thickness to far out on the crank. What happens is the starter plate is about .02" to far out on the crank this moves the 2nd gear the spacer and the 1st gear clutch out by the same amount. When you torque down the nut things bind up. It has a simple solution however, when you are assembling the starter plate section of the motor. There is the lower plate (with the friction material on it) then there is a return spring then there is a bit washer then there is the cir-clip and then there is another shim washer and lastly the engagement plate that the 2nd clutch mounts on. If you leave the last shim washer out and install the engagement plate directly onto the cir-clip the binding issue goes away. That shim washer is the exact thickness that the cir-clip grove is offset.

It took me hours to get to the root cause of it on one motor I built, pulling things apart and measuring everything, checking against an stock crank and reassembling. Once I figured out the fix was so easy I took it for granted.

Re: za50 crank shim advice/help in mass

I tried your suggestion with the motors but they still didn't have enough clearance to not bind. I would rather have the starter plate ride on the shim than the circlip IMO. I guess it depends on the internals and each crankshaft.

Re: za50 crank shim advice/help in mass

Any way to modify the drawings for the manufacturer and have the next set able to use the shim that belongs in there Paz?

Re: za50 crank shim advice/help in mass

hmmm. i missed Paz's post about the width of the crank webs being different when a new con rod is pressed in. the friend that pressed mine is a motocross mechanic so i am wondering if i am having the same issue...

puch service manual

anyway, i did put shims under the crank bearing races per the puch manual

pg 69 "before installing the clutch side bearing fit a .1mm shim"

then heated the bearing up and tapped it on the crank with a pipe with similar ID

but i ALSO shimmed the magneto side crank bearing per page 70 diagram (its got .1 on the trans side, .2mm on the magneto side) and tapped on race as above

I'm wondering if maybe the crank webs were too wide apart from the new rod being pressed in. with the case halves bolted together, I CAN move the crank, it's just not super easily. if i hold a rag around the magneto end of the crank and turn, the crank moves moves etc. I asked one of the boys down here: he said that with new bearings and seals it might be a little tight, but he's only done e50s. plus i am not 100% that the case bolts are torqued to 6 ft/lbs

should i take the races off and remove the shims? how easily should a crank turn in the case? no resistance at all? i'm pretty sure the bearing cups are all the way in. unsure about seals, the wiki doesnt have specific photos for the seals and the manual is sorta vague/ drawings are small.

also i am wondering if this is contributing to the other problem where the drive plate gear is slightly elevated in comparison to the main shaft gear. see photo. those are supposed to be lined up correct? the only thing i can think of besides the crank webs/ shims being too wide is that maybe the starter plate is not seated all the way down on the engaging plate causing the drive plate to be higher than it should...i'm pretty sure i've got the spring/shim/clip/ shim on there correctly, i got the clip into the little grove and the washer seems to be evenly seated.


Re: za50 crank shim advice/help in mass

let me take a measurement of how far my webs are apart I have an old crank laying around. I will say that with new seals it can be harder to turn but should not be very difficult. The new seals are very tight so there is a considerable amount of friction.

Re: za50 crank shim advice/help in mass

its not impossible, just tight. thanks Ben, if its just tight seals i will be happy but that still leaves the gear alignment being off...

Re: za50 crank shim advice/help in mass

It's hart to tell if the crank is binding with the seals installed as they create drag, I always check and adjust my crank shims before I install the seals. Without the seals the crank should turn very easily with no binding what so ever.

Re: za50 crank shim advice/help in mass

Seals will make it a little stiffer, but should still turn by hand with the case bolts tight. (edited)

Re: za50 crank shim advice/help in mass

it turns, with case together, just tight...

i did check the issue with the starter plate splines/ bushing being under that shoulder; it was not. if anything it was flush maybe even a bit higher than the shoulder.

so i'm going to take the crank bearing shims off, re-press bearings (if possible, if not i will get new ones), check again. the cups are flush with the case so i don't think thats playing into the "tightness" of the crank

also, i'm thinking this is not going to make a huge diff in where the splines sit in relation to that shoulder on the crank, so i will have to machine that down a tiny bit.

so Jake, when you were thinking that getting a new rod pressed into a stock crank might perhaps circumvent the alignment issue of the splines with that shoulder, not necessarily. obviously i am having the same issue with my set up as you have seen with the aftermarket cranks.

probably would be fine if i would have given my buddy the measurements between webs prior to removing the stock con rod so he could press it similarly, but who knows maybe the roller rods are a few mm wider than stock as well? i haven't measured them but if i can find that stock rod i will compare them

Re: za50 crank shim advice/help in mass

Is your internal clutch cable adjusted too tight so it is pushing the splines over the shoulder?

Distance between the webs doesn't affect the shimming in the clutch area.

Re: za50 crank shim advice/help in mass

the internal cable isnt even on and it still sits too high (double checked with and without)

and, didn't really think the web distance should affect the clutch, but it may effect the crank bind.

i'll check without seals before taking off the bearings

Re: za50 crank shim advice/help in mass

And these are the stock parts and your stock crank, just with new bearings and a new connecting rod? Should all work together if it's in the correct order.

Re: za50 crank shim advice/help in mass

yes. not sure why its not sitting on there correctly. you can sorta see it in this photo


Re: za50 crank shim advice/help in mass

OK so is the reason this race crank is longer by just a tad so you don't need to s

him the clutch cover side.I am becoming to believe that is why the manufacturers made them like that.

Re: za50 crank shim advice/help in mass

Ben - it sounds like you're getting to the bottom of the problem, especially with Paz on board...but I'll offer up my experience too.

I rebuilt a ZA with my brother and had a major binding problem when putting it all back together. Turns out the races and bearings were actually different sizes and ended up being too tight. These were brand new bearings and races from Treats and even though they were 'the correct ones' they were off by just enough for it all to bind badly when we torqued down the case bolts.

I went to Mars' shop at MIT and he had bearings and races lying around. We found the right ones and things simply dropped right in. Crank spun super smooth and nice.

So...while it might sound like you have a transmission shim issue on that crank, I wouldn't rule out the obvious that you have a bearing or race that isn't quite the right size.

That was just our experience though.

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