Setting Timing On 4k

[Big_Valven]

I'm trying to set the timing properly on my 4K (not hi cam, KE70 though.) I have had issues with it backfiring into the carby and a lack of power at low RPM.

 

I haven't done it before but I roughly understand the process. Timing light on cylinder 1 (front cyl,) timing should be around 8 deg as indicated with vacuum advance line disconnected from distributor.

 

When I first connected the timing light, it indicated at least 30 degrees!? I loosened the distributor but as I adjust it back towards 8 degrees, the engine starts to hesitate and eventually stalls. Even back near 20 deg, the engine will idle but hesitate badly as I try to free rev it. I have tried adjusting idle control which helps the idle, but obviously still hesitates when I try to rev it.

 

I have just put it back to a point where it will free rev properly, but it still seems to be around 30 deg. It is running better at low revs now though so it must be set a few degrees differently now.

 

If anyone can think of anything I'm doing wrong or anything else I can try, let me know. ;)

[Raven]

Where are you from champ?

 

Someone in your local area may be kind enough to come and show you how to do it.

[Big_Valven]

I live in Adelaide but I'm working on the car 3 1/2 hours north east of Adelaide in the Riverland...

[altezzaclub]

How many revs is the motor running at when you have the light on??

 

The centrifugal advance will work over 1100rpm or so, so if you have it up over 1000rpm it will be advanced beyond 8deg.

 

You can set it to start with by taking the top off the dizzy, turning the key on and rotating the motor by hand to the 8deg pulley mark.

 

Then rotate the dizzy until the points just open and you hear the crack of the spark. Make sure you have the points opening on the right shoulder and moving in the correct direction when you do it.

 

While the dizzy cap is off it would pay to suck on the vac tube and see that the points plate rotates and springs back OK. You should be able to rotate it by hand also, and have it spring back.

 

That will be within a degree or so and the motor should run quite happily.

Edited June 20, 2010 by altezzaclub

[Big_Valven]

I've had a quick squiz and also done a slight variation on your method by testing with a multimeter for continuity on the points to adjust static timing with the engine off, but it would seem that the rotor in the dizzy is indeed still about 30 deg off for the engine to run properly - anything less and it just starts dying and won't rev freely, or under load.

 

It would also seem that TDC is at the rearmost cylinder at the moment, is this correct?

 

At it's current setting (basically where it started to rev freely and not bog down, about 30 deg,) it's running brilliantly to drive and low down power is better with no backfiring. but traditional methods tell me it's not set properly.

[KENut]

Sounds like its set right. Probably isnt actually 30 degrees.

Which notch are you using on the crank pulley? Theres one on the back, two on the front.

That caught me out before, use the rear mark.

[altezzaclub]

Yes, check the notches and also check the blindingly obvious things that are easy to miss...

 

Which way does the rotor turn? Are you measuring the correct side of the shoulder?

 

Is it right for the plug lead sequence??

 

Are the centrifugal weights moving in and out smoothly?

 

Numbers 1 and 4 pistons move together so it doesn't matter which one you set the timing on.

 

Maybe work your way around a full turn of the dizzy with the multimeter on it watching the points and the crank pulley together. There is still something very wrong in there that will seem so obvious in hindsight.

[towe001]

Are you using the original crank pulley on the motor or have you swapped it for something else ? Cause the timing marks can vary between motors

Crank Pullies

 

I'd almost be willing to say that the plug leads are in the wrong spots on the dizzy cap....