123Ignition Static Timing, Engine will not start Options

[SteveNMaine]

The dizzy drive gear installation and proper position is covered in both the Haynes and factory manual

http://p914-6info.net/PDFs/Group%201%20Engine%20914-4.pdf

I’ll post some better pictures of a properly oriented dizzy drive gear shortly (within next hour) for your reference of what it looks like vs the grainy photo above

The bottom line is the drive is asymmetric - the smaller section goes toward passenger side and is angled about 12 degrees counter clockwise to the case centerline. The drive gear has 12 teeth - so being off 1 tooth advances or retards the timing by 30 degrees. Likewise - these often get installed 180 degrees off.


Note: this needs to be set at TDC of cyl#1 compression stroke (ie both valves closed)

Note: If you have to re-index the drive gear — Be careful when you pull the drive out. There is a thrust washer on the bottom that will stay in the engine under the drive gear. Hopefully you’ve seen this washer before and are familiar with it from the rebuild.

Looking at the installation page it says the timing mark should be at 7.5* on the 1974 1.8, my engine is a 1975 2.0. Whitch mark should I be using?

[cassmcentee]

Here is a pic of how mine is installed, I believe I set it at TDC,,,

[Superhawk996]

Looking at the installation page it says the timing mark should be at 7.5* on the 1974 1.8, my engine is a 1975 2.0. Whitch mark should I be using?

Focus on step 1. The orientation of the dizzy drive gear is set at TDC cyl#1 compression / firing stoke.

Have you verified that is installed properly?

[SteveNMaine]

So, I removed the 123 dizzy and checked the drive gear position, it was at 45* so I reset it to the 12* position and reinstalled the 123 dizzy iaw instructions.

Spark is blueish white and jumps at least 1/2 inch. Checked spark at plug 1, okay.

I loaded several different curves and still no start.

Before
After

[emerygt350]

You need to be more descriptive than 'not start'. Does it try? Did it backfire through the carbs?

[Superhawk996]

Good job putting the dizzy drive to correct position - that was definitely off by a tooth.

For the moment - forget about the dizzy curves - they have nothing to do with starting and idling. It’s just a distraction at this point.

Have you gone back and reset the 123 green light at 0 degree TDC after reorienting the dizzy drive?

Likewise - I’d have the same question as Emery, what exactly is it doing when you try to start? What do the plugs look like after trying to start?

[Superhawk996]

Also have questions about the carbs.

1) Are these brand new carbs as in absolutely new? (That is to say, not just “new” to you but previously used & abused by someone else) Have you set them up according to directions that usually come with a new set of carbs ?

2) Do you have linkages hooked up? If it were me - I’d disconnect all linkages and make sure the throttle butterfly’s are are fully closed on both carbs.

[iankarr]

Hang in there! As others have said, it will be worth it. I agree with Superhawk that going back to basics in a situation like this is best. The engine needs fuel, spark and air to run. Sounds like you've already verified spark and probably fuel...although if the fuel isn't atomized properly and the air mix isn't right, the engine won't turn over. I think this is where Superhawk was going with the carb questions. Does it stumble or kick over at all with starter fluid?

Are the intake manifolds firmly sealed against the engine and carbs?

[SteveNMaine]

The carbs are brand new; linkage is hooked up to both carbs and the accelerator pumps squirt fuel.

With the 123 programmed curve at 10 @500 and 28@3600 it will "chuff" at 1/2 to 3/4 throttle and the cranking rpm will increase very slightly like it is trying to start but that is it.

[Superhawk996]

The carbs are brand new; linkage is hooked up to both carbs and the accelerator pumps squirt fuel.

With the 123 programmed curve at 10 @500 and 28@3600 it will "chuff" at 1/2 to 3/4 throttle and the cranking rpm will increase very slightly like it is trying to start but that is it.

It sounds like carbs are aren’t set up properly. Please look into the things below before we go into carb setup.

The way you’re throttling it, you are effectively disabling the starting / idle circuit of the carbs but don’t have the engine “lit” and your not pulling enough airflow & vacuum to enable the main circuit.

Ian raised a very valid point to make sure you don’t have vacuum leaks at the heads or at the base of the carbs.

You should be able to start the engine with the throttles closed and pulling fuel exclusively off the idle circuits. Sometimes it may be necessary to use the throttle to shoot a couple shots of fuel to enrich the earliest cranking but even then I’ve usually cranked and started with the throttle butterflies closed or maybe only barely cracked open if the mixture is too rich.


Two asks:

1) try cranking it with the throttle completely closed and linkage disconnected. what happens?
2) post pictures of all 4 plugs

[OrangeBones]

It might be the fueling but if you can shoot video and share here with a link, the experts already engaged can be better positioned to help. Good luck!

[emerygt350]

Engines start easier a little retarded on the timing as well. If I were in doubt I would change that 10 @500 to 7 or even 6 @500 .

[IronHillRestorations]

I’m still not convinced that the timing is set at TDC on #1.

How have you determined TDC @#1 ? Turning it until the mark lines up isn’t enough.

[fixer34]

I’m still not convinced that the timing is set at TDC on #1.

How have you determined TDC @#1 ? Turning it until the mark lines up isn’t enough.

Been watching from the sidelines, yea something basic is still wrong.
We determined fuel is getting to the cylinder.
Spark is getting to the plug.
Now they just have to be there at the same time.

Set the flywheel/dizzy to where you believe is TDC #1. Pop the valve cover for the 1/2 bank and make sure both rockers have play on #1.

OR, swap the plug wires on the cap across from each other 1<->3, 4<->2 (IIRC) and see if it makes any difference.

Doesn't have to be dialed in to start; may run like crap, but it will at least run.

[iankarr]

Is there a new cam in the engine? If so, I'd make sure as much is right with the engine as possible so you can break it in for 20 minutes at 2K rpm. You don't want to stop and start with a new cam.

[Rob-O]

I’m still not convinced that the timing is set at TDC on #1.

How have you determined TDC @#1 ? Turning it until the mark lines up isn’t enough.

^^^^^^ THIS!!!

[IronHillRestorations]

I’m still not convinced that the timing is set at TDC on #1.

How have you determined TDC @#1 ? Turning it until the mark lines up isn’t enough.

Been watching from the sidelines, yea something basic is still wrong.
We determined fuel is getting to the cylinder.
Spark is getting to the plug.
Now they just have to be there at the same time.

Set the flywheel/dizzy to where you believe is TDC #1. Pop the valve cover for the 1/2 bank and make sure both rockers have play on #1.

OR, swap the plug wires on the cap across from each other 1<->3, 4<->2 (IIRC) and see if it makes any difference.

Doesn't have to be dialed in to start; may run like crap, but it will at least run.

Post#10

[IronHillRestorations]

Take the driver side valve cover off and confirm both valves are fully closed
AND the TDC mark on the impeller is lined up with the notch in the hole in the top of housing. Remember it takes two full revolutions of the crank to complete the firing order.

At this point the distributor drive should be indexed as previously posted. Check and verify.

Take a sharpie and mark the lip of the distributor where #1 is going to be.

Install the distributor and use that mark to make sure the rotor is in the ballpark. If you can’t get it close, then you probably have to the change the drive gear a tooth.

Set the distributor orientation (static timing with the LED) as per the instructions. Snug the distributor clamp enough so you can still rotate. If it doesn’t start, have a helper turn the key as you rotate the distributor a few degrees.

I chased my ass a little installing a 123, and it was my bone headed mistake. Once I assumed nothing was correct, and confirmed everything; it was as easy as the other two I had installed.

[IronHillRestorations]

duplicate

[SteveNMaine]

Is there a new cam in the engine? If so, I'd make sure as much is right with the engine as possible so you can break it in for 20 minutes at 2K rpm. You don't want to stop and start with a new cam.

It has a SCAT C25 cam with 96mm x 71mm P&Cs, will that make a difference in the ignition timing?