1964 FLH Spark Plugs Fouling

[Iacovos]

Cotton,

The float, if working incorrectly, could dialed down the fuel calibration as I stated.
Tightening the clamps, if they are leaking, would do the opposite.

Yes, I have not read an older service manual where the technical writer has published the kilo- volts.

We have come along way with tooling, method's and procedures. Even from the 80's when I started service Shovelheads and the new Evolution series.

A lot has changed over the years indeed and the adaptability of modern tooling and methods has been a positive thing.
I know these things from what is coming down the pipeline
(Future technology) and from where we've been.

I truly feel blessed to have grown up in shops servicing Flatties, Knuckles, Pans, Evo's, Twin Cams and M8's.

The older ones have always been a passion and a challenge to improve upon.

Apologies for getting a little off track,

Duke Kleman

No need to apologize Duke - had not been off track

As i am coming from the generation after….we need to learn from your experiences, expertise and also read on your stories

Jack

[Iacovos]

Modern USA fuels, Jack,

Cause many "rubbers" to expand, and eventually fail:

P4ORING1.jpg
ORING.jpg

Viton resists far, far better.

Its been decades for me, but the traditional "unleaded" kit just meant nitrided valve stems, guide seals, soft castiron guides, and often-disastrous hardened seat replacement (Knucks are already 'hard'),

I doubt the effectiveness of any out-of-a-bottle additive, except to lighten your wallet.

A simple discussion of bubble-testing can be found at http://virtualindian.org/11techleaktest.html; A constant, regulated air supply is critical.

....Cotten

Cotten when you say a regulated air supply is critical, i have seen tests carried out with a bicycle air pump.

Will the bicycle air pump suffice to the test? Will help a lot


Please see pic of the equipment
Also here is a video on youtube


https://youtu.be/qHZ9DMSiehM?list=TL...Y1oxNDA0MjAyNQ

[dukekleman]

Lacovos,

You want an air supply line, from an air compressor, that you can connect to a pressure regulation valve and gauge.

This will allow to to adjust the knob on the regulator to a specific PSI for testing. This then provides a constant and consistent supply of air while searching for any unwanted leaks.

The photo you supplied in your post shows both spark plugs being equally contaminated by the byproduct of a rich combustion chamber. Try to focus on those causes.

This would be locating reasons for too much fuel, slow burn rate of the fuel being supplied/used, lack of spark intensity, lack of proper air supply (filter) and lack of proper oil control in the combustion chamber.

Hope this helps,

Duke Kleman

[Iacovos]

Lacovos,

You want an air supply line, from an air compressor, that you can connect to a pressure regulation valve and gauge.

This will allow to to adjust the knob on the regulator to a specific PSI for testing. This then provides a constant and consistent supply of air while searching for any unwanted leaks.

The photo you supplied in your post shows both spark plugs being equally contaminated by the byproduct of a rich combustion chamber. Try to focus on those causes.

This would be locating reasons for too much fuel, slow burn rate of the fuel being supplied/used, lack of spark intensity, lack of proper air supply (filter) and lack of proper oil control in the combustion chamber.

Hope this helps,

Duke Kleman

Thank you Duke

Will do so

Just a clarification

lack of proper oil control in the combustion chamber - This would had the plugs wet / oily as well right? The plugs are very dry BUT black

[dukekleman]

Lacovos,

In the event of combustion chamber oil control, it can occur at different levels.
Very excessive lack of control issues will exhibit a more visual wet oily appearance on the spark plugs while also showing signs of oil contamination out the exhaust system.

Smaller issue will not show those particular signs. However they will contaminate the air and fuel mixture, changing the burn speed rate of combustion and show up on the spark plugs.

Your spark plugs are the camera that every gas engine comes factory equipped with.
They will tell you many things that are occuring during the 4 cycle events in your engine.
From various AFR's at various throttle positions, to ignition timing and heat events. All connecting the dots...
The next level of informative Data comes from oil sample testing. Inexpensive and very informative!

Hope this helps,

Duke Kleman

[T. Cotten]

You need a constant, regulated air supply, Jack,

Because the manifold cannot hold pressure, as the valvestem to guide clearances are orders of magnitude larger than ordinary leaks at the seals.

Tire pumps, air mattress pumps, and even shop vacs have led people astray with false negative results. (Schrader valves must have their cores removed, and testplates are a lot easier to install when the boltholes are tapped. Mine are made of ABS plastic for safety, and use replaceable solenoid gaskets. Avoid excessive fittings or heavy hoses that can move the assembly before it is tightened.).

With the regulator set to no more than 1 atm (~15psi), you can quickly tell when the intake valves are closed as the pressure will rise and fall as you turn the motor through.

....Cotten

[Iacovos]

You need a constant, regulated air supply, Jack,

Because the manifold cannot hold pressure, as the valvestem to guide clearances are orders of magnitude larger than ordinary leaks at the seals.

Tire pumps, air mattress pumps, and even shop vacs have led people astray with false negative results. (Schrader valves must have their cores removed, and testplates are a lot easier to install when the boltholes are tapped. Mine are made of ABS plastic for safety, and use replaceable solenoid gaskets. Avoid excessive fittings or heavy hoses that can move the assembly before it is tightened.).

With the regulator set to no more than 1 atm (~15psi), you can quickly tell when the intake valves are closed as the pressure will rise and fall as you turn the motor through.

....Cotten

Noted and thank you Cotten.

Both intake valves closed right?

[Iacovos]

Lacovos,

In the event of combustion chamber oil control, it can occur at different levels.
Very excessive lack of control issues will exhibit a more visual wet oily appearance on the spark plugs while also showing signs of oil contamination out the exhaust system.

Smaller issue will not show those particular signs. However they will contaminate the air and fuel mixture, changing the burn speed rate of combustion and show up on the spark plugs.

Your spark plugs are the camera that every gas engine comes factory equipped with.
They will tell you many things that are occuring during the 4 cycle events in your engine.
From various AFR's at various throttle positions, to ignition timing and heat events. All connecting the dots...
The next level of informative Data comes from oil sample testing. Inexpensive and very informative!

Hope this helps,

Duke Kleman

CLEAR

Thanks a lot Duke!

[Iacovos]

Will get working on the old 64 FLH and update as I go along.

THANKS FOR ALL THE INPUT

HIGHLY APPRECIATED!!

[T. Cotten]

Both intake valves closed right?

It is not necessary to release any adjustment on the valves, Jack,

The gauge tells you when they are closed.

..Cotten

[T. Cotten]

Lacovos,

In the event of combustion chamber oil control, it can occur at different levels.
Very excessive lack of control issues will exhibit a more visual wet oily appearance on the spark plugs while also showing signs of oil contamination out the exhaust system.

Smaller issue will not show those particular signs. However they will contaminate the air and fuel mixture, changing the burn speed rate of combustion and show up on the spark plugs.

Your spark plugs are the camera that every gas engine comes factory equipped with.
They will tell you many things that are occuring during the 4 cycle events in your engine.
From various AFR's at various throttle positions, to ignition timing and heat events. All connecting the dots...
The next level of informative Data comes from oil sample testing. Inexpensive and very informative!

Hope this helps,

Duke Kleman

As far as oil control problems, Duke,

A common cause I encountered with customers' machines originated at attempts to seal the sprocket shaft to accommodate a belt drive.

With a sealed manifold and a proper float, Jack can then determine if there really is excessive oil in the chambers or not. He already noted that it was dry sooting.

I used to regularly 'button-off machines while cruising for a plug "reading". But by the early '90s, the fuels made it futile.

...Cotten
PS: About that 'camera', its about time somebody hooked one up to a Colortune! (I'd hope there is already a vid somewhere...)

[Iacovos]

It is not necessary to release any adjustment on the valves, Jack,

The gauge tells you when they are closed.

..Cotten

Noted sir

Thank you

[otis71]

You also mentioned gas was leaking presumably from the vent meaning float level is too high.

[T. Cotten]

You also mentioned gas was leaking presumably from the vent meaning float level is too high.

Even with a proper float at proper level, Otis,..

It will overflow while sitting if the petcock leaks.

No floatvalve is absolute.

....Cotten

[gitguy]

Hello everyone
We had been working on a second 64FLH (not the one we rebuild the carb and changed manifold seals - which is working great).
on this second FLH we did timing, new plugs and reset the carb as per manual.
The bike would run ok however if you tried to open the throttle quickly it would hesitate/cut-out.
After three runs the spark plugs fouled (see pics)
How can i back track and fix this?
Where to start?
Facts are:
1) Carb was rebuilt 2-3 years ago
2) In a box given with the bike i have found a spare brass float (so probably carb was rebuilt with brass float)
3) Have not performed vacuum leak and not sure if manifold seals where replaced at the time the carb was rebuilt
4) on couple of occasions i found some gas leak from carb (believe from small hole)
5) Both plugs appear to “blacked out” the same (see pics)

The idea is to pull off the carb and do a rebuilt and change the float if brass

also change the manifold and carb intake seals

Anything else i could be missing?

Thanks a lot

The service manual states to adjust the low speed needle out five full turns from lightly seated and that the motor will start but it will be rich. My recent experience doing this on a newly rebuilt 48EL is that five turns is WAY too rich and my plugs looked just like the ones in your photo. I discovered that about two turns instead of five did the trick. Of course this is just a starting point. If that fails then any of these other suggestions should be explored. Just my 2 cents . . .