Paolo M

Jiml,

We apply a program to change the cranks an all the existing engines (on new engines on our warehouse shelf, on new engines on dealers shelf and on used engines on customers hand) So i am pretty sure that if you buy an engine you should get the revised version. Anyway, if by any chance you get one of the previous version, we will send a new crank, either thru your dealer or directly to your home at no charge

I hope with this info you can rest assure that we are comitted to give the best possible customer service.

Paolo Morganti
Serpent USA

jiml

iTrader: (3)

Cool. Thanks Paolo.

theRED5

Bad cranks or not, this is the best engine around. And notice I didn't say "for the money".... Even at much higher price, I'd recomend it.

isuzuguy

iTrader: (1)

where in the states can u purchase a zx-12 ?

markp27

Hi Guys,

I was trying to tune my Mega ZX-12 Race at the track today, but I had to make the bottom end so rich - way beyond what I would expect - I ended up with just over 8 turns out on the LSN!!!
I took my engine apart and I found that it has 0.5mm worth of head shims Is this normal?

I'm running the plug that came with the kit and 16% fuel.

To set the LSN, I used some advice that Paolo gave on the 710 forum. Pinch the fuel tubing about 5mm from the end and if the engine still idles for 5 seconds at the same revs and then goes higher before cutting out, then it is ok.

I must say, once I had done this it was flying, with the engine temp at 90C - but after a few laps, its pickup wouldn't be as good. And when I release the throttle in the corners, the revs remain high for a couple of seconds.
The idle screw is set as low as I can get it without the engine wanting to stall - looking into the barrel, the gap is small - it isn't like I have a big idle gap to hold the engine alive, due to a rich bottom end.

Should there really be so many shims under the head?

Any advice would be welcome.

Cheers, Mark.

markp27

BTW: For Goldfinger and Pyramid (and other 710 runners)

The lower end torque of this engine seems amazing - I had the Pyramid clutch setup (1.8 spring, yellow shoe, black clutch shoe cut into three for the flyweigts - clutch gap 0.6mm endplay 0.2mm + pre-tension 2.0mm) and I couldn't put any power down for wheel spin It was just eating up the road!!!

I increased my pre-tension to 2.2mm and now the power is more controllable and this is with the LSN @ just over 8 turns out!!!!

roadrage

iTrader: (14)

I have a zx.12 and on the track it bogs on bottom end for a sec or to then goes. it is not to lean,only running 220-230 range. i am running the 1.8 spring and yellow cluth shoe. can any one help?

Paolo M

Mark, i ansuwer this in the 710 forum

Paolo

Paolo M

Airleaking.........that's the problem. So far i had same problem in 1 engine. The 2 cams that you use to fix the carb at the crankcase in some case are some tents too long, and so even if you tigth the screw all the way down, still the carb is not really tigth and some air leaks from there (i had 1 engine that with the screw all the way, the carb was loose :weird
To solve this, you need to take out the 2 cams, grind a little bit and then the problem is solved.
Anyway, if there is no airleaking and the engine is running good and progressively is becoming lean, i normally rich the HSN (wich since is the "main" needle, it will also rich the bottom at the same time.

About compression, at sea level with 16% you should use 0.3 mm. Anyway, reading the plug is the best way for me

Another tip is the oring inside the crankcase (there is an internal oring inside the crank where the carb is located. I have had some bad experience with the internal oring cause the fit is so tigth that in several cases when you install the carb you strip the oring and the black parts goes in the crankshaft making a mess (not a big problem, is easy to solve, but anyway). I am using my engines without the oring (i use only the oring that is in the carb and no problem at all.

Paolo
Serpent USA

Paolo M

Isuzuguy,

All our dealers carrie the Mega line and the ZX-12 engines.
At the moment we are out of stock but we should receive a large shipment by the 3rd week of this month. Please check with your LHS about stock.

Paolo
Serpent USA

altezza

What is difference of using the collet that comes with the Mega engine vs the collet comes with the Centax II ?

I am still fighting for a good clutch setup for my 950R/ Mega. Advice from you is appreciated. Many thanks.

speedy100

despite which collet to be used, the most important thing is there will be enough clearance between the flywheel and motor. make sure there will be no binding between the flywheel and motor when they are pressed all the way down.

Joe Chaplow

thanks for the help........

GoldFinger

Congrats !!
If I may suggest you, dont use deeper than 1.7-1.8 mm .
If you do that, your spring height is reduced by 0.1 - 0,15 mm after several tanks. Which is not good for long main.
Maybe add some compression would make more low torque.
Just some thought.

Maxx

iTrader: (1)

When going from one brand of fuel to another, but keeping the nitro % (both 20%), do you need to break the engine in again for the different brand fuel or just adjust the carb to fit the new fuel?