Setting the timing

[sandythelandy]

Hello all, I have a 74 series III with a IIA 2.25 engine. I need to set my timing but really have no idea where to begin. I don’t have a timing light so I want to do it by ear. Can someone please give me the most basic explanation there is! I’ve never done this before so please assume zero previous experience/knowledge on the subject!

Also, the PO installed a weber carb that I’m told is running too rich (black stuff spurting out tailpipe and gurgles a bit), how do I adjust that?

Thanks for your help

[Billy5]

Which Weber do you have? I have a 32/36 DCV on mine. On this one, the following is the procedure. First back out the idle screw then back in just until it touches the arm. Screw in 1-1/2 turns. Then the mixture screw. Here you want to screw it in until it stops. Do not force it, just till it stops. Then back it out 2 full turns. Start the truck. Screw the mixture screw inward until the truck runs worse, then back it out until runs good. You shouldnt have to go more than 2 turns out for it to run well. I had an issue because I didnt realize my servo failed, and the vac leak messed everything up. I am running about 1-1/2 turns out. This is of course all depends on timing as well. Here I assume your truck is running and driving ok, and you want to just check it. I would suggest a timing light. I have three marks 6-2-0 ( I think). reading from left to right standing in front of the truck. One of two must be set to zero. Either the light or the truck ( using an advance light). When I did mine, I set the light to 8 degrees BTC, then moved the dizzy until the mark lined up with zero on the pointer. I am now at 8 degrees ( again I think I am new at it too). Truck runs great. As for ear, I have read that you can run the truck, then advance the timing until you hear pinging under load. Then retard it until it goes away. I would say do timing first then carb. Idle is affected by both so, the more advanced you are, the higher the idle. I am around 900 rpm. Hope this helps
Billy

[sandythelandy]

Thanks for the response. Although I would like to use a timing light, I can't afford one right now. So I guess I need to know everything there is to know about doing it by ear. Can anyone give me a quick run down??

Thanks

[Apis Mellifera]

Assuming the truck is in decent tune otherwise, start it up and with the distributor pinch bolt slightly loose, twist the distributor in each direction. You will see how the engine runs as you go from extreme advance to extreme retard. You'll have a range of motion around 180 degrees. The truck probably won't run unless it's somewhere in the middle 90 degrees. Somewhere in between the extremes, the engine idle will smooth out. If the truck runs now, you're already in the right neighborhood. Go for a drive, accelerate, go up some hills, etc. You should be able to find the balance of enough advance where you're making max power, but no so much advance that you get detonation under load.

If there is wear on engine, chances are the timing parts will have enough slop that you wouldn't get precise timing anyway, so a light wouldn't help much.

[LaneRover]

Thanks for the response. Although I would like to use a timing light, I can't afford one right now. So I guess I need to know everything there is to know about doing it by ear. Can anyone give me a quick run down??

Thanks

The Rover books I have list how you can do the timing static with a 12v bulb and some alligator clips.

I am surprised the beer method hasn't come up yet!

I'd describe it but others do a much better job!

[stomper]

I'll saveyou the search. Here is all you need to know.

http://www.roversnorth.com/forums/showthread.php?t=8887&highlight=timing+beer