Hi Anil,
Ignition timing for a 999cc FIRE engine is 2 degrees BTDC. This is with the vacuum advance DISCONNECTED and plugged. As far as I'm aware the ignition timing should only be checked this way, and not with the vacuum advance connected.
Yes, you can check the timing yourself. You need what is known as a timing light/ gun, and you connect this to the battery and also to number 1 spark plug (at the cambelt end of the engine). If you look at the gearbox where it joins the engine you'll see a black rectangular cap (unless it's fallen off!) Remove this, and underneath you'll see the edge of the flywheel and also a metal pointer with numbers on it. If you can rotate the engine while looking at the flywheel you will see a notch on the edge of it (TDC on the engine). Highlight this notch with white paint, and also the '2' on the metal pointer.
Remove the vacuum advance tube from the distributor and plug it to stop any air leaks.
Now start the engine. It will idle a bit roughly but that is normal with the vacuum advance disconnected. If you have a tachometer make sure the engine is idling aroung 850 rpm. Point the timing light at the timing marks on the flywheel. The strobe effect of the light should make the flywheel mark appear stationary in relation to the metal pointer. You need to have the timing mark on the flywheel align with the '2' on the pointer.
If the marks are out, stop the engine. Loosen the two bolts that hold the distributor to the side of the cylinder head just enough so that the whole distributor can be rotated. Don't loosen it so much that it is so loose it won't stay in place when moved! You need some resistance when it is rotated.
Now start the engine again and point the light at the timing marks. With the strobe still showing the marks, rotated the distributor so that the marks move towards each other. If they move further apart then rotate the other way!
Once the marks are lined up, stop the engine and tighten the two distributor bolts. Start the engine again and check the timing to make sure it is still correct. Once you are happy with the timing, reconnect the vacuum advance tube, and fit the rectangular plastic plug to the gearbox hole. You have now checked/ set the timing
To answer your last question about your Uno vibrating on 1st start in the morning, I assume you mean when the engine is cold? Mine runs a bit rough until until it has warmed up, which is quite normal on older engines. If it runs fine when it's warmed up (and the choke is off - if yours is fitted with it) then I wouldn't worry!
Hope this helps!
Chas
Thanks rajeev,
i had asked you about pipe that leads to governer mechanism. I will also try to check the airfilter hose condition and engine compression as explained.
By the way I want to know,
- what is the timing of FIRE engine without vacuum diaphram connected and with vacuum diaphram connected.
- Can the timing be checked/adjusted by our selves? if so, what is the procedure?
I have observed my UNO engine is vibrating (appears not normal) more during 1st start up in the morning. Is this due to bad timing?
please advice
Thanks
Anil