Roelof

Depending the fuel it can be a very clean burn shows like a new piston and head with on both a black/brown C-mark on the piston to a brown colored piston like coffee with milk. The plugwire will keep a shiny silver color with maybe a little bit black on the 1st winding.

If the piston and head turn to ugly gray with a rough surface the engine is to lean or it has a to high compression, the plugwire can turn to the same and will bend in the same condition

gfilos

in my mega zx 12 dsII+ engine i have a total 0.4 mm of head shims. Run a picco 6 cold plug.

If your orion engine is picco based (version 2008), the button is the same as well as the carb.

roger999

iTrader: (13)

that's strange.... On exploided view of mega zx is 2 gaskets one is 0.1 and 0.2... Now im confiused.....
if you can check clerance in engine would be great....

gfilos

my engine has 2 of 0.2mm head shims (from stock) and 0.4 mm shims is what all people use for mega zx and piccos for 16% nitro. Now, i am on a vacations, when i come back i can check it for you.

roger999

iTrader: (13)

ok thanks, now i just wonder what difference would be if i put 0.3 not 0.4? Can i destroy .it or what? That engin will be like spare i need it just for one race now....

gfilos

just put a new plug in, run it hard for a 1-2 tanks, bring it back in and inspect plug wire, color of piston and for pitting. pretty much what Roelof said just before.

roger999

iTrader: (13)

ok will do, thanks

roger999

iTrader: (13)

hi, im just back from the track...
engine looks fine.. is nice color... piston almost silver... button little bit like light gold )) plug on wire is more caramel but just the and, all wire is silver... any way engine working very well

about gearing... still something wrong... now is 2 gear but veeeery late.... sounds like engine is struggle on 1 gear and after that is second... i have changed just bell... will change next time one way... dont have new shoe... yet. will try on 2 used spare... will see..
im not sure how much tight screw on shoe...

gfilos

ok, the way you describe sounds like a good tune. Light gold color is a good indication. As far as the 2-speed:

1) First adjust the gap. Screw both grub screws equally until the shoes touch the bell (moving the bell will also move the shoes), then back off 1/2 of a turn on both grub screws. This way you ll have a clearance between bell and shoes, but it will be minimal. You can use a feeler gauge instead. Having a small gap helps the consistence of shifting and also reduces the wear on the shoes. Having a large gap, makes shifting harder, sometimes inconsistence and wears the shoes a lot.

2) The problem you described can be solved by adjusting the two allen screws on the shoes. just unscrew them equally until shifting comes when you want to. By unscrewing them,shoes can be open with less rpms and thus 2speed comes earlier. Do very very small adjustments (1/8 of a turn) until finding the perfect shifting point. Motor has to be in temp and tuned.


First adjust the gap at home to mimimum and then adjust the shifting point at track.

good luck

Roelof

The number tof turns you use to set the right gap must be losened on the shift setting screws.

gfilos

usually when you adjust the gap to smaller, you have to tighten the shift screws (not loosen) because shoes have to travel less to contact with the bell.. I dont know if the number of turns is the same, but i have no reason not to believe it

Geezatec

Serpent 2sp gear box. You have(2x)M3x16, and (2x)6x7, Use 2mm & 3mm allens.

3mm allens Tighten the Screw down till it freezes the flywheel, then loosen till freewhells freely.

2mm allen Bottom out the two screws, then turn each one 4 turns out. That should take you close. Loosening the 2mm screw early shifting, Tightening the screw delays the shift. 2mm screw should be adjusted at the same time. 1/8th or 1/16th turn each adjustment.

I paint the 2mm screws red, and 3mm screw white. It'll be easier to ID the screws when adjustment is needed.

Good luck!

begintravel55

sounds like good tips

roger999

iTrader: (13)

ill check saturday on track... Hope will be fine. Have no new parts yet...

gfilos

actually, shifting screws are 3x12mm and gap screws are 3x3mm. Shifting screws need a 2mm allen and gap screws need 1.5 allen. No need to paint them also...