I have searched but cannot find any listing on how to set ignition timing on the petrol dexta.
I did find the timing cover , and found the mark for TDC with a white dash at TDC.
I assume using a timing light but does it get set to TDC?
and after new cap , rotor, and wires on a new to me tractor that had not run in 10 years . where do I set the distributor at to initially fire it up?
Thanks
Corey
setting timing on petrol dexta
Re: setting timing on petrol dexta
Well, since petrol dextas are a bit rare and therefore the experience group is also a bit rare I will post what worked for me.
I rotated the engine around untill I saw the 0 TDC mark stamped into the flywheel viewed inside the timing hole on the left side of the engine.
I made sure my distributor rotor was in the same area as the number one spark plug terminal and with my timing light hooked up and the trigger pulled I rotated the distributor back and forth till my light pulsed a bright flash. Then I gently tightened the distributor clamp so it wouldn't move and started the tractor. Once running I adjusted the carb till it ran as good as it could then at an idle I used the timing light to set the timing to 5deg btdc. Why 5 deg ? well its stamped into the flywheel and they must have put it there for a reason....
Hopefully that helps someone in the future that also has a petrol dexta.
BTW if anyone has the extra part of the dexta manual that covers petrol engines I would be very grateful for the file or weblink.
Thanks
Corey
I rotated the engine around untill I saw the 0 TDC mark stamped into the flywheel viewed inside the timing hole on the left side of the engine.
I made sure my distributor rotor was in the same area as the number one spark plug terminal and with my timing light hooked up and the trigger pulled I rotated the distributor back and forth till my light pulsed a bright flash. Then I gently tightened the distributor clamp so it wouldn't move and started the tractor. Once running I adjusted the carb till it ran as good as it could then at an idle I used the timing light to set the timing to 5deg btdc. Why 5 deg ? well its stamped into the flywheel and they must have put it there for a reason....
Hopefully that helps someone in the future that also has a petrol dexta.
BTW if anyone has the extra part of the dexta manual that covers petrol engines I would be very grateful for the file or weblink.
Thanks
Corey
Re: setting timing on petrol dexta
Corey,
Here's the manual section you are looking for. You can download or print it. Sounds like your timing procedure was correct.
https://www.scribd.com/document/9585678 ... dson-dexta
Bill
Here's the manual section you are looking for. You can download or print it. Sounds like your timing procedure was correct.
https://www.scribd.com/document/9585678 ... dson-dexta
Bill
Re: setting timing on petrol dexta
That method was not bad but I still had the occasional pop back into the carburetor. I decided to try a method I used years ago on an old car I had using a vacuum gauge. You adjust the timing to get the highest vacuum reading then back it off "just a bit". However the old zenith carb doesn't have a vacuum port. I decided to remove the pipe that goes between the intake manifold and the valve cover. plugging my vacuum gauge into the hole in the intake manifold I started the tractor and adjusted the distributor back and forth till I got the highest vacuum reading then back just a bit till I saw the reading move just a tiny bit and then tightened it down. I also then adjusted my idle mixture screw on the carb the same way . After that it sounded smoother, I could bring the rpm's much lower and it starts easy. Using that method sets everything up the best it can be to your individual engine no matter if its freshly rebuilt, worn out or someone assembled something one tooth off on the timing gears etc. And of course you need to put that pipe back when your done or it wont run at all. 