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Valve Timing

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3 years 2 months ago #218346 by asw120
Replied by asw120 on topic Valve Timing
I sometimes run them off another battery.
Good also if there is no battery on the engine being checked.

Jarrod.


“I offer my opponents a bargain: if they will stop telling lies about us, I will stop telling the truth about them”

― Adlai E. Stevenson II
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3 years 1 month ago #218803 by cobbadog
Replied by cobbadog on topic Valve Timing
Back onto this head ache today and found an issue.
Firstly it is the wrong model distributor but having said that it did the job in the past. This one is a Model DY4A CA10 instead of being a DZ4A CA10. So I would like to source a correct one just for fun.
Next the rotor button is what appears to be the original David Brown rotor going by the direction of the arm on the end but because this is a different dizzy it is not a good fit onto the shaft. The gap on the end of the shaft is wider than the lug inside the rotor so there is a little bit of movement in this position.
You can see the internal mechanical advance before I cleaned it up by spraying carby cleaner down there but never took it apart and is all clean and lubed now and you can feel the springs pull the shaft back when you release some pressure.
Point gap is at 0.012" on all 4 lobes as it was mentioned to check this for a bent shaft.
Sorry about the pics being arse up, again I corrected and saved them before posting but!

Cheers Cobba & Cobbarette
Coopernook, The Centre of our Universe
Working on more play time.
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3 years 1 month ago #218804 by mammoth
Replied by mammoth on topic Valve Timing
Since you last ran it you have done several tidy-ups so I would suggest at this stage to set the timing (remembering that the auto-advance holds it retarded) and give it a run. I doubt that the one letter difference in the dissy spec represents much difference.
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3 years 1 month ago #218833 by cobbadog
Replied by cobbadog on topic Valve Timing
Yes I have the endoscope on charge at the moment so I can get the best idea of a look inside the front fuel tank looking for flakey rust and also check the fuel tap before doing the start up.
My only concern is the rotor button being able to move a few degrees and I cant imagine of finding a way to stop it moving and setting it in the correct position. But yes another start up will be in order tomorrow I hope,

Cheers Cobba & Cobbarette
Coopernook, The Centre of our Universe
Working on more play time.

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3 years 1 month ago #218837 by Lang
Replied by Lang on topic Valve Timing
Cobba

You could use some epoxy putty or liquid metal two pack paste to build up the rotor engage tag or make the slot in the shaft a little smaller. Not much pressure on there and should hold well to stop it rattling around.

lang
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3 years 1 month ago - 3 years 1 month ago #218839 by wouldyou
Replied by wouldyou on topic Valve Timing
Hello Cobba,
Wind the motor forward until the points begin to open, put the distributor cap on and mark the body below the cap directly below the plug wire the rotor is facing, then remove cap.
The section of the rotor directly above this mark is from where the spark will travel, think you will find a fair bit of unused brass either way and rotor movement on spindle unimportant.
David.
Last edit: 3 years 1 month ago by wouldyou.
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3 years 1 month ago #218842 by cobbadog
Replied by cobbadog on topic Valve Timing
Sounds like a good plan. I do have some U-Nead-It on the shelf that would do the job.
So there is already small raised sections on the dizzy body at those refference points below the plug terminals. So I should centre the rotor button arm halfway over those?

Cheers Cobba & Cobbarette
Coopernook, The Centre of our Universe
Working on more play time.

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3 years 1 month ago - 3 years 1 month ago #218844 by wouldyou
Replied by wouldyou on topic Valve Timing
Yes Cobba,
After having the points just opening when turning motor forward at timing mark on flywheel.
That would be for no 1 cylinder, once timed correctly could be checked on any.
David.
Last edit: 3 years 1 month ago by wouldyou.
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3 years 1 month ago #218849 by JOHN.K.
Replied by JOHN.K. on topic Valve Timing
I would use a timing light ,often you can see the firing point jump about on the flywheel ,caused by wear in the dizzy.....this was a big problem in the old Hyster forklifts ,sometimes the engine would run Ok ,other times it had no power......caused by the distibutor spindle moving and causing variable ,or no ,point gap.........manifold leaks are easily cured with silastic.
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3 years 1 month ago #218908 by asw120
Replied by asw120 on topic Valve Timing
Further to what David said, it is the points opening and not the rotor position that determines exact timing. The rotor only gives it to the correct cylinder.
Another thing - does the mechanical advance return fully by the springs (disregarding movement in the gears) Often the springs are loose due to wear. Can't remember if you've already done that.
Lastly, technically the rotor button is the little carbon plunger in the cap which pushes on the rotor (the bit you are concerned is loose)

Cheers and keep going!

Jarrod.


“I offer my opponents a bargain: if they will stop telling lies about us, I will stop telling the truth about them”

― Adlai E. Stevenson II
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