Plugged jet on carb, or... ?

[roadnsky]

What's kind of cool Jerry is if a guy insisted on numbering from the trans end to the flywheel end the firing order would still work out fine.

Yeah, I can see it. (Distro 180 out)
But I'm worried that Newbies who might read this will be confused with the basic A4 wiring??

[ndutton]

Yeah, I can see it. (Distro 180 out)
But I'm worried that Newbies who might read this will be confused with the basic A4 wiring??

As was I my friend.

[keithems]

wow!

i beg to differ...

there is actually a difference between firing order and cylender #...
as stamped on the manifold [i can't even spell it now...]

if u assume the one firing at tdc is # 1 [the first]...then that's the one at 6 o'clock on the distributor [i think -- will check tomorrow]-- .. then --going clockwise ...omg! -- it's late now and i'm pooped.. all i know is my a4 is running great!... first time out tonight -- no problems -- lots of power, etc.

and i'm quite sure if the wires were attached wrong...it would not be working so well..

maybe either way works so long as we remember that # 4 fires before # 3.

i'll photo it tomorrow...

[keithems]

i'm thinking without going to look..

#1 re. firing order means the one u want to fire at top dead center...which u determine by cranking the flywheel around until you feel compression as it reaches 12 o clock high...that cylinder then is the one you want to fire...right?

[keithems]

ok -- per the operation and maintenance manual for the a-4 from medalist-univeral motors form 298249, page 7..."ignition timing":

"the #1 spark plug terminal on the distributor [is] usually toward [the] engine block.."

so i've always attached the wire from that location on the distributor to the plug closest to the trans .....then moving clockwise..#2 -- [at 6 o'clock looking from above] goes to the 2nd one in from the trans .... then the next one is # 3...that wire goes to the # 4 plug..closest to the flywheel..and the last [at noon looking from above] goes to the # 3 plug --2nd in from the flywheel or third up from the trans end...

is this clear now?

[keithems]

maybe it doesn't matter where you start so long as the sequence is 1-2-4-3.

[JOHN COOKSON]

maybe it doesn't matter where you start so long as the sequence is 1-2-4-3.

This is correct.
Jerry's picture is how the distributor was oriented when the engine left the factory. If #1 spark plug wire is in another distributor tower than the one furtherest from the block and the engine starts and runs correctly it means someone has rotated the distributor after it left the manufacturer.

TRUE GRIT

Edit: BTW you mentioned the engine was running a bit rough. Have you tried power timing and cleaning up the advance?

[ndutton]

Distributor and plug wire orientation doesn't matter as long as the rotor points to the post for each cylinder when at TDC and the sequence then follows the firing order clockwise. There is an advantage of belt clearance with the distributor oriented as in Jerry's picture but it has nothing to do with how the engine runs.

The discussion of cylinder #1 at the flywheel end is simply a convention but it's our, MMI's and Universal's convention and important for consistency in our ability to help folks coming here with questions now and in the future.

[keithems]

This is correct.
Jerry's picture is how the distributor was oriented when the engine left the factory. If #1 spark plug wire is in another distributor tower than the one furtherest from the block and the engine starts and runs correctly it means someone has rotated the distributor after it left the manufacturer.

TRUE GRIT

are you sure? the manual i directly quoted from [above] is the original factory owner's manual by universal which came with the motor. it specifically says the post closest to the block is usually the first to fire. since it says usually, it does allow for another post to be the first to fire. i've never changed the orientation of my distributor from how it was when i bought the motor in 2007. that said, i can understand that for reasons of consistency and alternator clearance it can make sense to use jerry's orientation pictured above. in fact i might try it myself, but not until i have a real good reason to mess with the distributor. [see below].

Edit: BTW you mentioned the engine was running a bit rough. Have you tried power timing and cleaning up the advance?

i've learned many profound truths from working on the a-4 and from don and my fellow afourians on this forum. one of the most profound is....d f w i [don't fool with it] if u don't have to.

in fact, i knew the fuel was messed up...so i had to deal with that and got it to run -- fine in neutral but not very well in forward. so, as i said, i changed the plugs. no harm in doing so [cheap and easy] but likely they had nothing to do with the problem. in fact doing so initially made things worse..motor wouldn't start or run at all. obviously, in messing with the plugs i knocked the coil - resistor connection off...in hindsight, that's why it wouldn't start or run. the only real problem was one of the plug wires was defective....hence that cylinder didn't fire..hence i was running on 3. so once i replaced that wire...and corrected the problem i had caused with the coil wire....she ran.

and as i mentioned the motor ran great all last summer. so i had no reason to think the timing had changed -- so i sure didn't want to touch the distributor until i tried something simpler first. which i did -- last night -- i moved the idle mixture screw about 1/8 turn richer...and that was all i needed to do.

took her out on the lake last night for the first time .. motor started and ran great ...so...i'm happy and done....and i'll be way more careful this fall about capping the filler and filling the tank when the boat is hauled out.

[roadnsky]

The discussion of cylinder #1 at the flywheel end is simply a convention but it's our, MMI's and Universal's convention and important for consistency in our ability to help folks coming here with questions now and in the future.

Thanks Neil. That is exactly my intention.

Also agree that one could choose to run their A4 with the distro TDC in another orientation as long as firing order is carefully maintained.
We just don't want to mislead or confuse future newbie readers.
Especially someone drawn to Rob's original post topic.

Please read the hi-lighted section on page 2 of the attached PDF from our host.