off topic:
The cheapest price for 135 LC SS in KL area. Cash price. anyone know?

yea, quite surprised when a friend of mine who used 60mm block + 28mm KIPS carb told me that his FC is about the same as normal bike. I think it depends on the mechanics who tuned the bike 

Then bigger block ma better loh since FC din inc, charge how much u spend to mod ur bike to 160cc, over 1k??? Or maybe list down all the item n price ^^ wa gatai liao hahahaha

Firing timing should be different at each rpm range.
Advancing or aggressive timing means it fires much earlier... more power but engine not so smooth.
Retarding or less aggressive gives a smoother ride less performance.

The degree in timing terms, is the angle at which the timing sensor pick up the timing marker, usually on something attached to the crankshaft... either the magneto, or for cars, the flywheel. The earlier it picks up, the earlier you 'trick' the CDI to firing the plug, and vice versa.

IMHO, 4 degree is a lot to play with. My guess, 0 degree would be the std setting.

Tuning:
At low RPM, if you bring timing forward, the idling RPM will drop and you can feel the firing less 'explosive'. Bring timing backwards, the engine starts to have knocking sound, and then at some point it will die...
At high RPM, try this, switch one notch to the negative side, do you feel difference? Then another notch...

Warning - making over-aggressive timing will cause engine damage. One explanation is the expansion stroke will work against the rotation of the engine, but your transmission and the movement of the vehicle will force the rotation to continue. This opposing force will damage the engine. This is similar to engine knocking (Happens when fuel too lean, or over-compression).

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Added on June 14, 2009, 12:54 amMy bike just did 150km using 3.6liter fuel...

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Added on June 14, 2009, 12:57 amI like a normal pick up of a race bike, something like 0-60 in 5 seconds.

I prefer a higher cruising speed than good topspeed... which is the speed before you hear the engine stressing. I cruise at 90 on my RGV, and 120 on my TZM...

Topspeed RGV 140, TZM 180 (very small rear sprocket, 44 vs 49).

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Added on June 14, 2009, 12:57 amWhat is TT?
What is TT?
What is TT?

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Added on June 14, 2009, 12:59 amSaranjeevi,
What's your experience with RGV? Boleh lawan ah?
I haven't test ride with a 125Z before...

You mean RGV cannot lawan 125Z or rxz?
The CDI, for long distance, I suggest use standard... Smoother engine and riding more comfortable bah.
If you want pickup, then increase timing by a notch or two.

I can't think of a reason to retard the timing.

The most important is do you feel fast. Its your bike.
retard means... there is some serious problem, as standard CDI is damn retard ady.

Variable spark advancement is the best. Every rpm response to different advance degree. Usually more at high rpm and less at lower rpm.

If your CDI is a programmable one. This is only the 1st phase of tuning.
2nd phase is to put the bike on dyno and verify if the degree advancement produced the best torque curve.

For adjustable CDI, we can only fix at one degree. Mine is 29 deg at the moment. The CDI will automatically adjust.
1500rpm - 5 deg
2000rpm - 10 deg
2500rpm - 15 deg
3000rpm - 20 deg
3500rpm - 25 deg
4000rpm - 29 deg
4000rpm and above 29 deg.

Starting from 5 deg until xxx deg that you set, the CDI will try to make a linear graph up to 4000rpm.
It is not very optimized though, but good enough, as I dont have a dyno machine to fine tune. Just use my butt dyno.

then if now i want to modi minor modifying...what should i modi?
after a long time of 150...a bit bored d...
can someone recommend me minor modi for my bike...cause still new...

Stock is using 10deg only.
Unless you are using stock + racing CDI (dual CDI), else you can't use the stock mapping at all.

Perhaps, the advance 1 - 4 deg is based on the default setting of your racing CDI, not the stock one.

Retard makes sense here then, because, the default may be 30 deg.
If you want 29 or 28, you gotta retard by 1 - 2 deg.

wA sat morning interesting maybe ^^ ask mai calvin.. Ei charge yamahat135 there haen selling 150cc vixion kit good bo??? Is it the FX150 enjine?? http://www.yamahat135.com/forum/viewtopic.php?t=462

Did you also notice an RGV up down left right Penang also? Haha, do you have that GIVI box with you when you did that trip?

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Added on June 15, 2009, 11:24 pmI don't like ppl with no road ethics or courtesy. Overtake ppl close close, or brrrrng loud loud passing by ppl. Really wanna 'gan' those ppl sometimes.
I highlight or double-honk from afar if I need to overtake, what do you guys think?

Paiseh, I no pro lah...

For the powerband, you must be referring to the exhaust valve control mechanism. Wikipedia has more information on the names every maker use, example Yamaha YPVS, Kawasaki KIPS, Honda RC Valve, Suzuki AVACS etc...

2-stroke engines that doesn't have such mechanism does not have the additional powerband (RG*, TXR Gamma, Panther, 125Z etc).

Per my understanding, this mechanism controls the exhaust valve opening. In brief, at certain higher the RPM, it 'opens' to allow earlier exhaust stroke. This causes a major change in the 'acoustics' of the 2-stroke engine and allows the RPM of the engine continue to rise creating a secondary powerband.
To replicate this effect, a race tuned 2-stroke engine will have an earlier exhaust porting to extend powerband to higher RPM. By doing so, performance at lowend sucks...

This is just a part of 2-stroke engine design. Exhaust design is another story. In brief, 2-stroke exhaust system is an expansion chamber that is 'supposed' to resonate at every RPM to increase the back-pressure which in turn, increase the compression ratio of the engine. Notice all 2-stroke exhaust cannot end with a huge tail pipe, else its a design failure.

Now, a bit on 4-stroke... 4-stroke exhausts generally sticks to a no-backpressure design, ie the bigger and straighter the better... and the compression ratio is modulated by cam timings. However, there may be literature that suggests benefits from back-pressure, similar to the effect of the 2-stroke design, that would benefit engine performance - which maybe why for cars, 4-2-1 exhaust manifold is for stock cars and 4-1 is for race tunes.

This is why Charge's LC has higher idle RPM than normal.

I hope can understand la... any clarification please ask lah... I don't mind explain.

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Added on June 16, 2009, 12:47 am

I didn't go to Farlim tho.
Duro racing good? Would you recommend to us? What's your rim size? Mine is 1.25 front, 1.4 rear... Cannot go more than 80 front, 90 rear.

Haha... sounds more like capalang brand to me... Thanks buddy.

Sounds good. Where does TK valves come from? Where is Bee Hock?

The same road as the Perodua sales center.
There are 3 bikes shop along the road. Bee Hock is at the center.

Tokico BM

It's S4 cam if not mistaken.
Ahh... end up I am the only one to the TT...

I dunno what's the difference. I js read the label there. haha.
I know it is a damn high cam, 330 IN / 290 OUT.

RM150.

Anyone noe how much is a new ori LC coverset selling in PENANG?? I juz nid a plain colour (no design).. 1 more thing here is about the MJ :110 PJ:22.5 does it suit for stock performance, and if next time i change carb will it still be fited?? And how much will it cost for those 2 item selling at BEE HOCK??? Anyone using it?? How is it??

OO thx saran...