OzVMX Forum

Marque Remarks => CZ => Topic started by: tony27 on March 20, 2011, 02:41:11 pm

Title: Flywheel swapping
Post by: tony27 on March 20, 2011, 02:41:11 pm
I had my 380 shear the woodruff key 1/2 a lap into practise at Whakatane yesterday & have discovered the taper is pretty marked up, is it possible to use a sidepiper flywheel on the later bikes?
The sidepiper flywheel I have sitting here has a lot more letters stamped on it
I'll try & get a couple of decent shots & post them tomorrow
Title: Re: Flywheel swapping
Post by: 090 on March 20, 2011, 07:52:12 pm
The old boy reckons that till the yellow tanker at least are all the same. Same crank and gears as well.
Title: Re: Flywheel swapping
Post by: Bamford#69 on March 20, 2011, 08:19:44 pm
Hi,
Ive weighed these flywheels
250 twinport           1630g
250/360 side pipe    1650g  (same part #)
125,250,380/400     1885g  (same part #) from a 74 parts book
988 Enduro has a different part#  I would assume it would be a heavier flywheel.
you can see the extra size of the heavier flywheels
 a 74 CZ part # is 980-61-110. is that the same as a 71 72 73 ?
 
 these figures are assuming that the ones I weighed were the original fittment and not swapped previously.
cheers
Title: Re: Flywheel swapping
Post by: tony27 on March 21, 2011, 04:55:09 am
Looking at the parts book that shows all the years part numbers on CZmadness it appears that the part number stayed the same from 68 until post 75, might take both to work & weight them next door at the plastic moulders
I'll spend a bit of time & see whether I think the damage is removable or if I need to get off my fat ass & finish the suzuki conversion
Title: Re: Flywheel swapping
Post by: Bamford#69 on March 21, 2011, 09:31:05 am
Hi,
the CZ  parts books list similar, but different part #s

the sidepipe parts book, lists the number as 980-61-010.

the 74 parts book lists the number as         980-61-110

cheers
 
Title: Re: Flywheel swapping
Post by: tony27 on March 21, 2011, 05:37:42 pm
Trust me not to see the extra 1 in the number.
Looks like I won't be using the sidepiper flywheel anyway, the thread for the puller has been beaten up a bit  :(
Anybody got a spare or should I just do the ebay thing?

(http://i788.photobucket.com/albums/yy166/tony27_photo/CZflywheels010.jpg)Taper damage
(http://i788.photobucket.com/albums/yy166/tony27_photo/CZflywheels014.jpg)Taper damage
(http://i788.photobucket.com/albums/yy166/tony27_photo/CZflywheels009.jpg)73 flywheel
(http://i788.photobucket.com/albums/yy166/tony27_photo/CZflywheels008.jpg)Sidepiper lettering
Title: Re: Flywheel swapping
Post by: jimg1au on March 22, 2011, 06:40:29 am
before you buy an other one try to lap the flywheel and taper with valve grinding paste.its the taper fit which holds the flywheel on not the keyway.when you have finished clean it down and put a small amount of coarse past on the taper and lock the flywheel on.a old trick my brother (jap454) told me works.
jim
Title: Re: Flywheel swapping
Post by: tony27 on March 22, 2011, 07:32:48 pm
Thanks for the advice Jim, had already decided on trying to lap in the tapers & brought home the tin of lapping compound from work
Spent an hour or so removing the transferred flywheel taper from the crank with diamond files then lapped the flywheel taper in as best I could, I reckon I've got about 70% making contact- too many deep marks to get out
Will see if I can source a new key tomorrow or maybe make 1 out of silver steel if I have to
Title: Re: Flywheel swapping
Post by: Bamford#69 on March 23, 2011, 09:12:24 pm
Hi,
if you are sure the taper is a good fit and the keyway isn't damaged use a Yamaha key #90280  03017,
should be available from any Yamaha dealer
cheers
Title: Re: Flywheel swapping
Post by: montynut on March 23, 2011, 09:30:33 pm
After lapping the flywheel on a motoplat ignition I had a problem with it still shearing the key. I finally found that the flywheel was going on the taper just enough so that when the nut was tightened down it was bottoming on the crank and flywheel together instead of just clamping the flywheel if that makes sense. Basically the nut was tight and the flywheel was held firmly in place but was not pulled and locked onto the taper. This meant that the key was carrying load instead of just locating the flywheel in its correct position. I made a stepped washer so that all the nut clamping pressure was exerted onto the flywheel and no more problems. It is worth checking as I have only found this on one of my bikes. The same result if the key is even a few thous high meaning the tapers can not lock together
Title: Re: Flywheel swapping
Post by: jimg1au on March 23, 2011, 09:47:02 pm
i found the same problem with the drive side on my 1972 380 made mods and it works great
jim
Title: Re: Flywheel swapping
Post by: bazza on March 31, 2011, 04:33:10 pm
tony what model suzuki parts were you going to use?
Title: Re: Flywheel swapping
Post by: tony27 on March 31, 2011, 05:09:58 pm
Have a ts400 flywheel mounted on cz taper with the stator plate turned down to fit, cdi is ts185er & I havent decided on whether to run the ts185 coil to a single plug or a rd400 coil which is narrower & fires both plugs at the same time
Mainly I need to find time to go back to work with the bike to make coil mounts & extend the wires from the stator
Title: Re: Flywheel swapping
Post by: tony27 on April 07, 2011, 07:03:20 pm
Have gotten round to making the coil mount for the RD400 coil & have spark but no joy in getting the bike running, nice red foot from a couple of kickbacks though
How do you set the timing with this set up?
Title: Re: Flywheel swapping
Post by: Ian P on April 08, 2011, 03:45:15 pm
Need a dial guage. Then set at 3.5mm btdc. Should work fine 8)
Title: Re: Flywheel swapping
Post by: tony27 on April 08, 2011, 03:48:54 pm
About to do that, should the lines on the flywheel & stator line up there or at TDC?
Title: Re: Flywheel swapping
Post by: 090 on April 08, 2011, 05:07:25 pm
firing marks.
Title: Re: Flywheel swapping
Post by: tony27 on April 08, 2011, 05:09:24 pm
Took the head off & checked to see where the lines met up, close enough to 3.5mm btdc-maybe slightly closer to the first line than the centre. Refitted head & checked for good strong spark, doesn't seem to matter which way I connect the cdi unit to the coil
Still no joy, the occasional kickback & the kickstart looks to be developing a bend
Looks like it's back to points for the last mr vmx round & taupo  :(
Hope the lapped in taper holds up
Title: Re: Flywheel swapping
Post by: Ian P on April 09, 2011, 12:49:14 pm
But where was if firing??
Title: Re: Flywheel swapping
Post by: tony27 on April 09, 2011, 01:42:01 pm
No idea, don't have a timing light & have been at work all day, at least I managed to make a decent mount for my dti while I was there
Title: Re: Flywheel swapping
Post by: Ian P on April 13, 2011, 03:22:44 pm
Sorted yet??
Title: Re: Flywheel swapping
Post by: tony27 on April 13, 2011, 04:07:43 pm
Points back in for the time being, will try again after taupo when I have more time
Title: Re: Flywheel swapping
Post by: jimg1au on April 13, 2011, 06:35:43 pm
tony
 how do you set up your points just want to make sure i do it the same as my 400 just dosent go as well as my cr250m 1973
thanks
jim
Title: Re: Flywheel swapping
Post by: tony27 on April 13, 2011, 07:25:33 pm
Use a dti with the head off, I set the phasing(x mark) at 3.5mm then used the thin paper trick to get the points to open at the same point
The bike isn't a first kick bike when it's cold but thats just because I haven't sorted the pilot jetting out properly yet, think I need to throw a #50 at it. When warm it starts easily