serious help needed guys! 2T ignition

[ctrain]

whoops i wrote that last part wrong, i took it for a drive and it runs good, im just waiting for it to crap itself as that was what it done the past few days, so to confirm it runs good for now, im hoping it stays that way, thanks heaps guys for all the advice.

Oh one more thing, with the new coil do i just not connect the ballast resistor to the coil and it will run or do i have to take out the resistor from the loom?

[roadkill]

I'm 99% sure that you take the resistor out all together. The new coil should have 3 connection points. One for 12v running, one for 12v cranking, and one for earth. I think.

bEn

[ctrain]

yeah its got 3 points one -ive and +ive and the lead connection to the dizzy

[ta22fan]

You should see a wire from the loom that connects to the back of the ballast resistor (usually bolted on top of the coil), then a short lead from the front of the resistor to the +ve coil terminal. Just move the wire from the back of the resistor to to the +ve coil terminal. Just be sure that the new coil is a 3 ohm unit (does not require ballast) otherwise you'll burn your points out real fast.

Good to hear that you've got it running Ok.

Cheers,

[Rodger]

When you say you have the piston at TDC and you set the rotor to point at cap position 1, it maybe close to being timed right.

Have you had a timing light on it?

Timing is keyed off the point opening and not the position of the rotor.

Setting the timing first up is almost the way you describe however:

Use the mark on the 2T crank pully which is the timing mark to set base timing, there are degree markings on the timing cover that does indicate TDC #1 but this is at the 0 mark. The engine is turned clockwise, coming up to compression on number 1, the mark is stopped at the desired static timing, say 10 and not at 0. If you over shoot go backwards past the point and come forward to it again.

This is where you install the dizy and set the rotor to point at #1 lead position.

Then rotate the dizy so the points sit on the cam if need be and gap the points.

Then to get the timing close to the desired value (without a timing light) turn on the ignition and slowly rotate the dizy body back and forward listening for the "click" of the point spark as the points rise up the opening cam. As it clicks stop turning and tighten the base clamp.

Install the cap and leads.

Then get a timing light on it.

As you have it now you may find it is not at a desireable timing value, yet you may have hit on a usable one with the slightest movement of the dizy during the course of your investigations. If the timing was set as you describe first up then you may have had 0 advance or even some retard and that would indeed spit vapor back out the carb.

10 degrees static would be a nice value on your motor.

Regards
Rodger

[ctrain]

i have it timed ok, it runs fine for now until i buy a dwell meter as i find timing lights useless on old motors because they dont compensate for wear and tear, the dwell meter gets it perfect, last time we timed it we had it at 10 degrees amd it ran perfect, but as ive replaced everything its all outta whack

[jb_22]

Look for a multimeter, around $25-30 should buy you one with dwell angle and maybe even tach signal. Set the dwell first, then set the timing. What's stopping you from going electric dizzy?

BTW I got mine going

Cheers, Jess

[ctrain]

awesome news mate! so was it 180 degrees out?

the thing is there is no pick and pay wreckers around Geelong their all closed private yards with a counter at the front, id rather go and find the cars myself because I know the exact models, i wouldnt trust some wrecker bum, plus CBF, i dont have the time for it nor the patience, mine runs fine so im happy

[ta22fan]

Dwell angle is a measure of your points gap, not your ignition timing. The dwell angle is a more accurate measure of how your points are set than using a feeler gauge. The only reliable way to set your timing is with a timing light.

[jb_22]

Changing dwell angle will affect the timing though, so every time you change the points gap you got to check the timing

[caam]

But a timing light is very useful regardless of the fact it's an old motor,
best and easiest way to set timing regardless of dwell settings, set them with feeler gauges and chuck your timing light on, couldn't be easier

[ta22fan]

The aim is to get a good strong spark delievered at exactly the right point in the compression stroke.

The points are basically just an on/off switch in the low voltage circuit through the coil. The gap on the points controls the length of time that the points are open versus closed. The coil works best, and delivers optimal high voltage to the spark plugs, when then points are closed for 52 degrees and open for 38 degrees out of each quarter turn of the distributor cam - hence a specified dwell angle of 52 degrees. A points gap of 0.4-0.5mm will get you close, but a dwell meter is more accurate. This setting will drift over time due mainly to pitting/wear on the points contact faces and wear on the cam following arm. Your condensor (basically an electrical capacitor) is designed to minimise this effect, but it can't be eliminated completely.

All going well, this gets you a good strong spark.

To get the spark delivered at exactly the right time - you need to set the timing to 10 degrees BTDC at idle with a timing light. You can set engine timing using a "static" method, but a timing light is quicker, easier and more accurate - and given that you need to re-do this process every 3-6 months, it's worth the investment.

Found a good manual on how to check and tune a 2T/3T engine here:

http://members.iinet.net/~stepho/man...ta/engine%20T/ (02 engine tune-up.pdf)

[jb_22]

Very well said sir! Or just go electronic ignition, eh callum?