jumping gear
08-23-2010, 01:11 AM
#1
jumping gear
hi all, my gear jumps from 1 to 2 and 2 to 1 all the time... Is no top speed... Sounds like something blocking engine. Just wonder can be that because my engine is too lean on the bottom? Engine is mega zx .12. Car serpent 720. I just fitted there carb from nova made for mega mf.
08-23-2010, 03:14 AM
#2
Be sure to adjust the shoes of the gearbox very close to the 2nd gear housing. If the gap is to large you will get this.
08-23-2010, 03:23 AM
#3
hi all, my gear jumps from 1 to 2 and 2 to 1 all the time... Is no top speed... Sounds like something blocking engine. Just wonder can be that because my engine is too lean on the bottom? Engine is mega zx .12. Car serpent 720. I just fitted there carb from nova made for mega mf.
2).check the 2sp shoes and bell for excessive wear. (if shoes are worn out, you wont have a consistent change) I would change shoes and bell. Also make sure you have a minimum gap between shoes and bell without any touch between these 2.
Sometimes its about the track and when having a fast turn you have this kind of shifting (jumps to second, then back in first). If this is the case, i would try to make shifting a little earlier so you can pass the turn with 2nd gear. If this happens at the straight, then something is wrong with 1) or 2) above.
and btw, the zx12 isnt happy when its too lean on bottom
actually it likes a bit richer than other motors. however this has nothing to do with your problem.hope it helps
08-23-2010, 04:10 AM
#4
ok thanks, so you mean that problem is with gearbox not with carb? Because i didn't change gearbox settings, i left it same like for orion... Just my orion is gone (back bearing faild) so i had old zx with no head button and i put head button from orion and carb from nova based mf... And its happened... Now i put carb from orion and ill check it on track again... In hand seems to be ok... On full trottle...
08-23-2010, 05:44 AM
#5
Did you check the real head clearance with the other head button?
08-23-2010, 06:49 AM
#6
no have no old button, so i fit orion button and underhead gaskets... You mean can be wrong clerance there?
08-23-2010, 07:05 AM
#7
But i still cant find in which way the motor could affect up-down gearing.
edit: which orion model do you have? there was a version after the first orion engine, which was made by picco, do you have this one?
Last edited by gfilos; 08-23-2010 at 07:11 AM. Reason: info
08-23-2010, 07:23 AM
#8
Yes, take a piece of 1mm solder, bend it into a L-shape and put it into the plughole so the endtip is touching the chrome on the cilinder. Turn the flywheel arround so the solder will be squeezed between piston and button, messure the squeezed solder, with a Picco I believe the thickness must be 0.5~0.6 mm depending the size of the head. If it is far off 0.5mm you have to change it.
If it is difficult to get the solder into the plughole just remove the heatsink and screw only the button head tight with the screws using some spacers.
If it is difficult to get the solder into the plughole just remove the heatsink and screw only the button head tight with the screws using some spacers.
08-23-2010, 08:51 AM
#9
Check one-way clutch. O/W clutch only function on load or acceleration. Clean and lube O/W and shaft. Remove 2speed shoes, and clean them with Scotts Brite. Adjusting screws, both bottom out, the 4 turns counterclockwise for starting out. Adjust to engine tuned. Speed shoes should be adjusted equally.
Good Luck!!
Good Luck!!
08-23-2010, 08:58 AM
#10
yes head clearance maybe wrong with the new button, you ll have to check it. Do your self a favor and buy a button for zx12. Its the same as picco. btw which version zx do you have? the very first one? (DSI?) if you have dsII or later, you dont really need a nova carb, it works just fine with the stock one.
But i still cant find in which way the motor could affect up-down gearing.
edit: which orion model do you have? there was a version after the first orion engine, which was made by picco, do you have this one?
But i still cant find in which way the motor could affect up-down gearing.
edit: which orion model do you have? there was a version after the first orion engine, which was made by picco, do you have this one?
08-23-2010, 09:03 AM
#11
Yes, take a piece of 1mm solder, bend it into a L-shape and put it into the plughole so the endtip is touching the chrome on the cilinder. Turn the flywheel arround so the solder will be squeezed between piston and button, messure the squeezed solder, with a Picco I believe the thickness must be 0.5~0.6 mm depending the size of the head. If it is far off 0.5mm you have to change it.
If it is difficult to get the solder into the plughole just remove the heatsink and screw only the button head tight with the screws using some spacers.
If it is difficult to get the solder into the plughole just remove the heatsink and screw only the button head tight with the screws using some spacers.
Last edited by roger999; 08-23-2010 at 09:19 AM.
08-23-2010, 09:39 AM
#12
Should work.....
Just squeeze it a bit with a pliers and try to get the flat spot in the line of the piston.
Just squeeze it a bit with a pliers and try to get the flat spot in the line of the piston.
08-23-2010, 09:58 AM
#13
but for sure is not less than 0.5. Leave it or put one more gasket 0.1?Ok, i have done it... just found view mega engine with parts and there is under button 2 gaskets 0.1 and 0.2 like in my zx now... i hope that button is same like in picco engines... clearance is about <0.5...
Last edited by roger999; 08-23-2010 at 10:59 AM.
08-23-2010, 11:10 AM
#14
A to large clearance will give a low power engine, when fiering up and running it just cheack the coloring of the piston and buttonhead and the shape of the wire in the glowplug.
08-23-2010, 11:23 AM
#15
ok what color should be ?
tomorrow ill check it on track (if the weather will let me do it), i have changed gearbox like somebody said b4... i hope will be good
tomorrow ill check it on track (if the weather will let me do it), i have changed gearbox like somebody said b4... i hope will be good
