Timing light Antics

[underdog57]

Thinking of intermittant ignition problem check .
On my inductive timing light it flashes around idle , then looks like steady light . Guessing around 5k it seems to look like it breaks up ....
Not sure if this is normal , but its a lot easier than watching plugs firing !!Wonder if this is usfull to look at , as its real easy to switch from one wire to the next .....

Bob

[randy]

Yes, timing light is an excellent plug diagnostic tool. Basically, if the light don't light, then your plug aint firin' either!

Around 5K you have a misfire? could be pickup coils, old plug wires or wrong plug gaps.

[underdog57]

Seeing The Light

Originally posted by randy
Yes, timing light is an excellent plug diagnostic tool. Basically, if the light don't light, then your plug aint firin' either!

Around 5K you have a misfire? could be pickup coils, old plug wires or wrong plug gaps.

The plug wires look like they came from the civil war ...
Might try the run it in the dark wet trick ...

I'm going to look at it again , just seemed on the two plug wires I hooked too , both seemed odd at mid rpm . Will look at all and see what it does ...

Bob

[DiverRay]

Bob, Check the plug caps as well. They get old, and the resistor will break down. New NGK caps are still available from many shops, including auto parts. Mine were about $5.00 each for new.

[underdog57]

See the light

Cool thanks !

Took it out today for a ride, its still rich on #1 plug . Part clean near the tip of the plug and puffy black everywhere else ...

I think the wires / ignition are ok , just the timing light does flash brigher than the bace light sporatically ...
Guessing thats normal ...

Bob

[randy]

Bob,

Have you tried a new plug in #1? Sometimes fouled plugs will not clean themselves if the carbon buildup is enough to continue the misfire

[underdog57]

Originally posted by randy
Bob,

Have you tried a new plug in #1? Sometimes fouled plugs will not clean themselves if the carbon buildup is enough to continue the misfire

Hi Randy ,
I've been switching the plug each time . The other cylinders look a great tan now , and they are like plug cleaners . Put a clean one in #1 and it gets sooty . It cant be too bad as its got a clean spot on it tip and electrode . I can run it and its never died even on a 60 mile trip I did the other day ...Actually more than 60 miles.
I'm sure this bike is getting known around town ...
Today it ran better , goes to idle quicker . It stumbles around 4.5k if accelerating . getting narrow on the dead spot .

I switched floats and mixed up all the idle mix jets . Was going to see if Ether around the idle mix jets did anything , but cant find it ...

I do see slight pitting and brass color worn off the emulsion jets ...
the jet that goes in the emulsion tube ...

But its so close to being right its rediculas . Have to Keep it going if it sits 20 seconds or so . These carbs look like they took some abuse before . Also saw the float bowls were forced to the side a bit . Each end where the gasket sits was smooshed a little . Pliers fixed that . Not sure if it helped or not ...

But if you take off full blast to 8.5k I run out of straight in 5th 7.5k . Does not take long to do that . Not sure hoe accurate the tach is . But the seat of the pants say it moving !!!

Will ride it and goof with the idle , looking into getting new idle jets although they look fine , but the little o-rings look tired ...

Speaking of tired , I have to get up at 4:30 the next three days for work ...
Later...

By the way looked at the pictures of the swamp rat , its awesome !!

Bob

[randy]

Bob,

I don't recall if anyone covered this point, but is the fouling dry and powdery or is it wet and oily? If oily, you cold have leaking valve seals in #1. Dry powdery fouling is from rich mixture.

[underdog57]

Dry and powdery , like lamp black ...
I did the same on all carbs , but this one has a slight hitch to it..
I could try lowering the fuel level more ...it was very slightly high last time I did the actual level check with the 1/4" tube ....
I set the floats to 26mm ....that within spec on the 78/79 carbs.
the xj manual gives you a spec for actual fuel level...

Bob
I dont mind riding it as is . but to get it right would be really cool...

[tommystinson]

Jet needles and needle jets are small tolerance parts. If the gold anodizing is worn off of one of yours then it needs to be replaced. The needle jets/emulsion tubes also suffer from wear with fuel contamination, but not as quickly as the needles. The Keyster carb kits come with the needles, most don't. I have a few extras, PM me and I'll send you one.

[79XS11F]

Out of curiosity .. Are you using a hard wired timing light or an inductive light? I ask because the inductive lights only work on one side of the coils. If I'm not mistaken inductive light only works properly on #1 and # 3 if the coils are wired as per factory set up. It has to do with the coil design. they fire positive and negative charges and on the negative firing wires the inductive lights are unreliable.
Rob

[underdog57]

Originally posted by 79XS11F
Out of curiosity .. Are you using a hard wired timing light or an inductive light? I ask because the inductive lights only work on one side of the coils. If I'm not mistaken inductive light only works properly on #1 and # 3 if the coils are wired as per factory set up. It has to do with the coil design. they fire positive and negative charges and on the negative firing wires the inductive lights are unreliable.
Rob

Hey Rob ,
Inductive , I tried it on #1 and 2 . acted the same on both .
just as it glows at higher rpm it flickers brighter , but it seems to work on both. did not try 3 and 4 ....
my guess would be my ignition is fine , but would like to compare how the light reacts ....on another system to compare ...
Thanks
Bob

[pggg]

If the plug's fouled/sooty then the timing light won't work properly, wirebrush the plug clean, the timing light should flash properly - until that plug carbons up again...