My Zbox 48cc HT Build!

[kjparker]

OK, been a busy weekend!

Noticed that there was a deep crack around the other rim I was using, so I looked in my pile of spares, and grabbed another wheel. This one however has a suntour 7-13 cog on it! 7 speeds all 1 tooth apart. My legs are going to get strong! Ended up fitting the friction shifter off my old 10 speed road bike onto the bars, as the 6 speed shifter wouldnt shift that cog! It's amazing whatr you end up keeping and using!

Ovehauled the hub, and the gearset, cleaned it all up, new grease in the bearings, it now rolls as smooth as butter! One hitch though, it was quite buckled! Took it to the bike shop (wooleys wheels great guys in there btw) and they sorted it for me.

Got the bars finished off, Managed to mount the clutch and brake levers both mounted so that they dont interfere with each other, and can be easily used!

Made my replacement bucking bar - 4 inch bolt+dremel = bucking bar.

Mounted up all the rest of the stuff, The kill switch i bought from Jaycar, fitted as if it was made for it! It had the matching bullet terminals on it all I had to do was put it in line with the blue wire! No cutting, joining, soldering, anything!

Had to clean up the drive gear a little on the motor sothat it would run smooth, might have to clean it up a little more, few teeth are still grabbing.

Didnt have a stand on this bike, and didnt know how to mount one. Managed to use the bolt off the tensioner, after chopping an inch off the end, was all good.....

Was also sick of having to manually align the rear wheel, as one side can go deeper into the dropouts than the other due to the derailer. Out comes the grinder again, and I now have a spacer for the other side that I cut off an old derailer! Works well!

Still to do:

* smooth drive cog on engine a little more
* Grease all cogs
* fit fuel filter, have one, but its a bit big for what i want to do
* Change tyres and tubes. Have a slow leak in the ones on there
* put fuel in and ride!

http://i18.photobucket.com/albums/b108/keithparker/done003.jpg
http://i18.photobucket.com/albums/b108/keithparker/done004.jpg
http://i18.photobucket.com/albums/b108/keithparker/done005.jpg
http://i18.photobucket.com/albums/b108/keithparker/done006.jpg
http://i18.photobucket.com/albums/b108/keithparker/done007.jpg
http://i18.photobucket.com/albums/b108/keithparker/done008.jpg
http://i18.photobucket.com/albums/b108/keithparker/done009.jpg
http://i18.photobucket.com/albums/b108/keithparker/done010.jpg
http://i18.photobucket.com/albums/b108/keithparker/done011.jpg
http://i18.photobucket.com/albums/b108/keithparker/done012.jpg

 

[will_start]

Woohoo, well done, let me know how that big filter goes. I think it will work until you get something smaller. Running without a filter, you risk carp getting into the Carbie.
But you can run without one to test out the setup.
Try it without first, then add it later. Don't cut the original fuel line,
as you may need it. I used Clear 6 or 8mm PVC for the lower half. Zip Tie the lot.

You got the exact same kill switch I did from JCAR, its water-proofed 15 Amper...

So, let me know when you're running, and we'll go for a ride.

 

[kjparker]

it;s Alive!

Hi

well, i took it for the first ride tonight, eeven if it was only up and down the carpark under my building!

Was a bit hard to start at first, but persistance got there!

Ok, now the problems:
* wont start / run at all with the choke on
* feels like its "bogging"
* at lowish speeds it has quite a bad shudder

I'm looking at the carby as being the issue, but open to suggestions...

 

[BoltsMissing]

* feels like its "bogging"

Ok, here's where the fun begins.
Let's start at "restrictions", namely the Exhaust Port/Gasket gas flow.

We already know it's a mis-match as in the shape of Engine's Exhaust Port and the Header on the Exhaust Pipe and it's relevant standard issue gasket.


Try this;
Remove the Exhaust Pipe, try to save the Gasket.
Fit the Gasket and lightly tighten on the Port with washers only, no exhaust pipe. This is to secure the Gasket.

Use a stanley kniife, dremel, file, whatever works and shape the hole of the gasket the same shape of the Port ( inside diameter-rectangle).

Use a nail file after so there is no gas restrictiion hitting up against the gasket like it would have been before.

Re-fit the muffler with a good quality sealant, but you may want to make few spare gaskets for later on while ya at it anyway.

I did this and it was a bit better, then I drilled holes inside the exhaust's baffle and it made a world of differance in performance at the low end, ( good take off)

It ain't yet perfect, but working on custom header and a slide-on exhaust fitting.
This mis-match is a real "dummie" of a thing, it should all match right at that point, why do thay have these obvious gas flow restrictions on the HT has me baffled.

If you don't cut away the gasket and match it up, it will only build up with gunk and eventually clog the exhaust passage, perforamce will gradually deterioate.

Don't worry about the mis-match in the exhaust pipe yet at this stage, it will naturally occur that it's a "to do" thing later on anyway to.

Once I get this header thing sorted on my builds, it will become the norm to do away with the standard exhaust pipe header we get in the kits.
Because I think, no matter what "upgrade" one does, be it spark plugs, plug leads etc etc, what's the point if the Exhaust Gas Flow Restrictions are not sorted out first ?

 

[will_start]

Man I'm going to print that out its so good,
great post bolts.

 

[nickk]

hi guys

hi guys just finshed fitting my z50 to my bike, and had first longer ride of 8km to work except being cold as **** it went well but surges it anything under 15kph which i think is more chain rattle up setting it more km will help
had to make different mount at front used exhaust clamp and a home made bracket as was very limited in space and did not want to drill frame as thats a weakness and might crack
good to see other peoples bike builds and get ideas from them good luck in your build is it up and running i'v included some pics
nickk

 

[will_start]

we met we rode, we switched parts and I left.

thanks keith, hope you enjoyed it, we'll ride again sometime.

I think it just needs to run-in a bit more and you'll get rid of the bogging.

In my humble opinion, until you have at least 5-10 hours on it, you don't know
what the engine will really be doing yet.

 

[BoltsMissing]

Just a quick update on the exhaust, the actual plate welded on the exhaust pipe that flushes on the engine's exhaust port, may need to be modified with "surgery".
Meaning, cut off the thin plate, shape and weld another thicker plate, I'd say about 1/4" thick, longer allen key bolts as studs lined with about 4 spring washers on each bolt with a flat washer on top and bottom. This is to allow for heat expansion using HT the spring washers.
Straight advice from an exhaust bloke who has done a few small engines on go-carts.
He had a look at mine and a few others and probably that is the way to go in his humble opinion.
Cost about $20 to get the welding done, (plus gaskets and steel plates, DIY with grinder/s and files)
The existing plate on the HT header maybe way to thin, it warps or does not sit flush.

 

[kjparker]

and let there be light!

As Will_Start saw last night have a dynamo light fitted to the front wheel of my bike. Whilst this would probably satisfy legislation, It isnt really a very bright light.

I then had an idea. See below:
http://i18.photobucket.com/albums/b108/keithparker/bike003.jpg
http://i18.photobucket.com/albums/b108/keithparker/bike002.jpg
http://i18.photobucket.com/albums/b108/keithparker/bike004.jpg

It's just held there right now with a hose clamp, I will get a couple of exhaust clamps, which I reckon will hold it solid!

I reckon I'll need about 30 minutes or so of light, and re-charging everynight isnt a problem, Thinking of this one from Jaycar:

7.2 Amp Hour 12V Sealed Lead Acid Battery

SLA
- Size 151(L) x 65(D) x 101(H)mm
- Charge current 720mA for 10-14 hours
- Discharge current 20 hr rate 350mA
Capacity:
- 20hr rate (0.35A) 7.0Ah
- 10hr rate (0.67A) 6.7Ah
- 5hr rate (1.19A) 5.95Ah
- 1hr rate (4.00A) 4.0Ah

- Int Resistance:
Fully charged (20°C,68°F) 25m Ohm
- Max Discharge Current (5 sec):40A
- Constant Voltage Charge:
Initial charging current < 2.1A
Cycle:
- Voltage 14.40V~15.00V @ 20°C (68°F)
- Temp Coefficient: - 30mV/°C
Standby:
- Voltage 13.5V~13.80V @ 20°C (68°F)
- Temp Coefficient: - 20mV/°C

Reckon that'll be good enough?

any idea how long it will last assuming a standard 55wat globe?

 

[Bogaurd]

Keith - 55watt's @ 12v = ~4.58amp current draw.

In theory, this will give you just over 1.5 hours of light - in practice, you're likely to get significantly less, probably around an hour or so. The reason for this is that SLA batteries do not perform well when discharged fast - drawing 4amps off such a battery is a fairly heavy load.