Topic: A little help please! w/vid

[johnsy]

So i finally got around to working on my bike 78 550k and im not burning 1 and 2. ive got spark and the plugs are wet but no burn. any suggestions. you can see me touching 1&2 but nothing. 3&4 are good
heres a vid.
thanks

IMG_3598.MOV

[wedoo2]

Could the valve timing be off?

[johnsy]

Could the valve timing be off?

thanks, ill give it a check.

[scunny]

you haven't swapped the spark leads on 1 & 2 ?

[lucky]

Could the valve timing be off?

Forget valve timing.
Do you have a timing light?

[lucky]

Give us some back ground info.
Did you adjust the points?

Do you know how?
If the points are used you will not be able to
 adjust them with out a dwell meter.

Are the condensers old or new?

There are other possibilities.

[johnsy]

Give us some back ground info.
Did you adjust the points?

Do you know how?
If the points are used you will not be able to
 adjust them with out a dwell meter.

Are the condensers old or new?

There are other possibilities.
 

dont have a timing light. can get one though.condencers are new, checked them for holding charge. im getting spark on both points this is the second bike ive done points adjustment on so im hoping its my newb points knowledge that its an oversite on 1&2 im going to go back into and adjust them again.
thanks for the info.

[johnsy]

you haven't swapped the spark leads on 1 & 2 ?

no i have not.

[seanbarney41]

just keeping things straight here...one coil, condenser, and points set fires 1 and 4, the other coil, condenser and points set fires 2 and 3

[JimM68]

just keeping things straight here...one coil, condenser, and points set fires 1 and 4, the other coil, condenser and points set fires 2 and 3

YES, what he said. If 3 & 4 are running, you have spark from both coils. I suppose you could swap wires between 1 and 4 (or 2 & 3) but that's a long shot.

The carbs are fed paired 1 & 2 and 3 & 4....

If you loosen the bowl drain screw on carb one does fuel drip out?

Thinking a clogged fuel filter, pinched fuel line, or petcock problem for the fuel feed for 1 & 2.

[lucky]

Some confusion here.

One coil fires cylinders 2&3
The other coil fires cylinders 1&4

You can use either wire from 2&3 to go to those two cylinders.
They both fire at the same time.

Same goes for cylinders 1&4, 1 &4 fire at the same time.


If you adjust the points gap and you cannot get the dwell in specs you have to buy new points. You cannot use a thickness gauge on a used set of points. Only on a new set of points unless the used set of points have NO PITTING.
The dwell is the amount of time(rotation of the crankshaft), before the charge the condensers are storing up is released to the spark plug.

Below is a drawing showing WHY you cannot use a thickness gauge on pitted old points. The points gap and DWELL must be in specification at the same time or the spark will be weak or no spark.

[MCRider]

Generally speaking, you can dress up pitted points with a point file. An ancient and archaic instrument, but they did exist. Without one, simply use some emery paper. Hit it with some points cleaner and you're good to go. We did it all the time.

Sure it won't be a primo tuneup, but even pitted points and out of spec gap shouldn't keep you from getting it started on all 4. In my opinion.

As stated by others, the points are paired 1-4 and 2-3. If its 1-2 that aren't firing, I'd have to suspect something else. (carbs)

Though it'll be good to get the ignition as close as possible.

[johnsy]

Some confusion here.

One coil fires cylinders 2&3
The other coil fires cylinders 1&4

You can use either wire from 2&3 to go to those two cylinders.
They both fire at the same time.

Same goes for cylinders 1&4, 1 &4 fire at the same time.


If you adjust the points gap and you cannot get the dwell in specs you have to buy new points. You cannot use a thickness gauge on a used set of points. Only on a new set of points unless the used set of points have NO PITTING.
The dwell is the amount of time(rotation of the crankshaft), before the charge the condensers are storing up is released to the spark plug.

Below is a drawing showing WHY you cannot use a thickness gauge on pitted old points. The points gap and DWELL must be in specification at the same time or the spark will be weak or no spark.

so basically if I do this wire swap with say 2&3 and 2 then fires its an old points issue, would that be the correct assumption?

[Killer Canary]

What they're saying is that if you're getting fire on 3&4, points and coils aren't the problem with 1&2.

[johnsy]

What they're saying is that if you're getting fire on 3&4, points and coils aren't the problem with 1&2.

ahh got it.

[MCRider]

What they're saying is that if you're getting fire on 3&4, points and coils aren't the problem with 1&2.

ahh got it.

Right. If its an ignition problem, whatever is wrong with 1, would show in 4, not 2.   Whatever is wrong with 2 should present in 3.

And old points can cause a poor running condition, occasional misfire, rough idle, etc. Something that you would want to fix. But rarely do old points by themselves cause no fire. Though it is possible, I suppose.