Valve clearances & carburetor synchronisation

Start by removing the tank and everything else that's in the way. Clean it, you don't want sand and other stuff in the engine
And yes, the engine needs to be completely cool before you start this.

Specifications (RD07)

Intake valves: 0.13 to 0.17mm
Exhaust valves: 0.18 to 0.22mm

Don't have the torque values, may hand is my torque wrench


Remove the caps.


Remove the crankshaft end cap and the timing inspection cap.
Start with the rear cylinder, rotate the engine anti-clockwise until the RT mark lines up. (You can unscrew the spark plugs to make it easier to rotate the engine if you want)



Make sure that the cylinder is at the Top Dead Center on the compression stroke by checking for some movement in the rocker arms and valve (= grab it with your fingers and move it up and down).
No movement = exhaust stroke. Rotate the engine 360° to change it to compression stroke. Then insert a feeler gauge of the correct thickness and check that it is "a firm sliding fit".
To adjust: Slacken the locknut and turn the adjusting screw, then tighten the locknut (make sure the adjusting screw don't rotate). Re-check clearence. Then turn it 720° (two full turns) and check the clearance again.



It's the same procedure for the front cylinder. But instead of rotating to the RT mark, rotate it to the FT mark. It's a bit more tricky because of all the crap in the way. You can/should displace the right hand radiator to get better access.


Check the o-rings before you put everything back.


Carburettor synchronisation
Warning: Petrol (gasoline) is extremely flammabel as Haynes would say.

You need something to check the sync with, either buy one or make one yourself. All you need is some clear tube, piece of brake line and some sort of oil.

Before you sync, you need to let it run to reach normal operating temperature. And set the correct idle speed (1200rpm +/-100rpm).


Here's my DIY. Filled with 2-stroke oil.


Made nipples/adapters out of 2 pieces of brake line. Used a threading tool? (don't know the english word for it) M5 threads.


Use something to restrict the flow. The Swedish king helped me out


Attach the nipple here, and the other one to the other side.



The bike need fuel to run, so make some sort of temporary tank. Or use extended pipes from the tank.


Something like this will help you turn the adjusting screw.


Connect the tubes and make sure it's a good fit. Air leaks will result i false readings. Start the engine. If it flutters to much, tighten the restrictor.If the oil starts to rush towards one cylinder, turn it off or you will have a lot of smoke .
If the reading is the same on both cylinders, you're done. If there is a difference you need to adjust.
To adjust: Turn the synchronising screw, it's in the throttle linkage between the carburettors. Accessed from below. Don't press hard on the screw or you will get a false reading. (Don't have a pic of it).
When they are in sync, snap the throttle once and check it again.


When you are done, put everyting back where it was from the start.
And if something went wrong along the way, don't blame it on me.

(If you see something wrong with the guide, let me know. With the steps or with the writing/language).