Spark color and s&s jetting... another time...

All Panhead related topics
Post Reply
Teo87
Posts: 13
Joined: Sat May 18, 2019 10:51 am
Bikes: 63 panhead
Location: Piacenza
Been thanked: 5 times

Spark color and s&s jetting... another time...

#1

Post by Teo87 »

hello everyone, I searched a lot in the forum but I still can't solve the problem (one of many) ...
I have been struggling with carburation for a long time ...
motorcycle configuration: s & s super E, bird deflector, 2 in 1 without silencer, engine completely redone (63, i have change the head with 2 almost new)
the bike starts at the first shot and runs perfectly ...
slow jet 29.5
main jet 72, 74.76 ...
with 72 and 74 it looks perfect, with 76 fat ...
Spark ngk bp5s
the spark are always the white
on the tip they are white, on the ring and deep black ...
they seem divided in half ... the tip is always clean ... the rear one slightly darker ...
does the color have to be gray? or with the current gasoline is it different? I am reading many different opinions ...
tomorrow I try with the bubble test (I have to build the plate)
I don't usually tighten the o-ring bands too much ...
can this be?
lately I have also used high temperature silicone ... I'm waiting for the ultra black permatex ...
Any advise?
thank you very much
Matteo



RooDog
Site sponsor
Site sponsor
Posts: 1770
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 793 times
Been thanked: 669 times

Re: Spark color and s&s jetting... another time...

#2

Post by RooDog »

Matteo
Why are you using silicone sealer anywhere?
The main jet is relatively unimportant for day to day running, in fact the motorcycle will run perfectly well without any main jet in place at all up to about 4000 RPM.
The slow/intermediate jet and the idle screw control most all your carburation around town and even on the highway until you open up the throttle and get above 4K.
I do not look to the plugs for tuning a street engine, I tune by behavior. If the engine starts and runs well at all RPMs what is there to learn from looking at the plugs? Unless they are oil fouled, leave them be.
Follow S&S's tuning instructions, and you should have a good running scooter.
I have two $&$ G models, one from Zippers with a Thunder Jet installed is on a 90" Shovelhead . The other is on a 100" Evo clone. The tuning procedures also hold true for Bendix and Keihin butterfly carbs too....

https://www.sscycle.com/tech-info/instr ... uick-guide

And if you are running an open exhaust pipe, especially dual drag pipes, do not expect perfect results....
Best Wishes....RooDog....
Last edited by RooDog on Thu May 21, 2020 9:36 pm, edited 1 time in total.

RooDog
Site sponsor
Site sponsor
Posts: 1770
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 793 times
Been thanked: 669 times

Re: Spark color and s&s jetting... another time...

#3

Post by RooDog »

=

Teo87
Posts: 13
Joined: Sat May 18, 2019 10:51 am
Bikes: 63 panhead
Location: Piacenza
Been thanked: 5 times

Re: Spark color and s&s jetting... another time...

#4

Post by Teo87 »

:D the silicone was a magic for the leaks from the Exhaust collectors ... I tried to use it also in the Intake ...
I read the link and I noticed that it talks about removing a screw (auxiliary bawl vent plug) if a filter other than the drip one is used ... can it create problems?
I mounted the new carburettor but I never unscrewed anything ...
I have already done the procedure to adjust the carburetion screw and it seems ok ... I always have the same result, just over 1 3/4 of a turn ...
I can try to go from 29.5 to 31 but I think it's big ...

when I go around the city at low rpm the sparks become dark, if I add the fast road they become half black (part passes) and half white (tip) ...
the detachment is clear and not nuanced ..

RooDog
Site sponsor
Site sponsor
Posts: 1770
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 793 times
Been thanked: 669 times

Re: Spark color and s&s jetting... another time...

#5

Post by RooDog »

If it don't sputter or miss, takes throttle without hesitation I wouldn't worry about the plugs. If you want to change that slow jet either up, down, or even try both, and see how it feels. I found that I needed to go up one more size on the intermediate jet to dial out a small hesitation I had at highway speeds due to the alcohol content of today's fuel. Still not looking at the color of the plugs.....
....RooDog....

Sarre
Posts: 104
Joined: Sun Nov 26, 2017 5:14 pm
Bikes: 1950 HD FL customized
1971 Honda CB750 K0 chopped
2003 Buell XB12s tuned
Location: Netherlands
Has thanked: 48 times
Been thanked: 48 times

Re: Spark color and s&s jetting... another time...

#6

Post by Sarre »

You can "safely" use a sealant for the exhaust, but I wouldn't use one for the intake and especially not for the carb.

My plugs look like this, a bit too dark to my likening but I'm not that worried:

Image

I think the fuel mixture screw on the S&S super e (only one I have experience with) actually has a big effect on the colour of the plugs at lower rpm's.

As @Roodog wrote, if it starts OK and runs good, and not oil fouled, then ride it.
Teo87 wrote:
Thu May 21, 2020 11:16 pm
I have already done the procedure to adjust the carburetion screw and it seems ok ... I always have the same result, just over 1 3/4 of a turn
You can always lean out the mixture by turning it inwards another 1/4th of a turn and see what the plugs do..

RooDog
Site sponsor
Site sponsor
Posts: 1770
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 793 times
Been thanked: 669 times

Re: Spark color and s&s jetting... another time...

#7

Post by RooDog »

Those plugs look like mine. Now take it out for a ride, say, 20 miles @ 70 MPH, and see how they look. Personally, I wouldn't worry about them, Just have a beer and chill....
Again, if you tune by the plug color at street level, you'll not like the way the bike starts or how it runs....
Also: Turn down that accelerator pump to a minimum it will quickly blacked plugs....
....RooDog....

Edaddy
Site sponsor
Site sponsor
Posts: 74
Joined: Tue Dec 05, 2017 8:49 am
Bikes: 1965 Panhead
1992 Jammer frame
43" Custom Springer
1991 Std Case
STD dual-plugged heads
Location: Bellingham wa
Has thanked: 6 times
Been thanked: 10 times

Re: Spark color and s&s jetting... another time...

#8

Post by Edaddy »

I struggled with my carb for a year with straight pipes. Added revursion cones and "lollipops" and it made a HUGE difference.

And if you are running an open exhaust pipe, especially dual drag pipes, do not expect perfect results....
Best Wishes....RooDog....
[/quote]

panhead
Site Admin
Posts: 2799
Joined: Wed Dec 12, 2001 9:17 pm
Bikes: 1954 FL
Location: Holland
Has thanked: 31 times
Been thanked: 199 times

Re: Spark color and s&s jetting... another time...

#9

Post by panhead »


Teo87
Posts: 13
Joined: Sat May 18, 2019 10:51 am
Bikes: 63 panhead
Location: Piacenza
Been thanked: 5 times

Re: Spark color and s&s jetting... another time...

#10

Post by Teo87 »

Bubble test done...
I found one leak....
do you think it is better to change or weld it?

Bone Head
Posts: 62
Joined: Wed Jul 31, 2019 5:27 pm
Bikes: 1956 Frankenstein
1998 Harley FXDL
Location: SW Ohio
Has thanked: 196 times
Been thanked: 36 times

Re: Spark color and s&s jetting... another time...

#11

Post by Bone Head »

Teo87 wrote:
Fri May 22, 2020 12:34 pm
Bubble test done...
I found one leak....
do you think it is better to change or weld it?
Exactly where was the leak? At the O-rings or the metal of the intake manifold itself?

O-rings and the metal where they mount should have nothing but a light coating of petroleum jelly applied to them to allow O-rings to seat in the assembly process. As I read your posts I got the impression you were using some sort of silicone sealer on them; this should not be done.

If the manifold itself is leaking somewhere besides at the O-rings, welding it would only be after no replacement was available.

I'll agree with others who say not to pay too much attention to the sparkplugs.

I hope this all makes sense, good luck. I'm eager to see a solution.

ozwick86
Posts: 903
Joined: Sat Jul 17, 2004 4:06 am
Bikes: '59 Pan FLHF
Has thanked: 6 times
Been thanked: 61 times

Re: Spark color and s&s jetting... another time...

#12

Post by ozwick86 »

If you have old rubber o-rings in there I would change them out for the Viton o-rings. The rubber ones swell over time from the Ethanol gas. You also need to check the manifold for pin holes and cracks. Make sure you spray it with soap and water while testing.

The O-rings should be installed dry with no sealants. Just tighten up the clamp until snug don't over tighten.

VITON
James Part Number: JGI-27002-55
JGI-27002-55
Gasket Kit, Intake Manifold,
USED ON: 1940-1965
MODELS : Linkert®, Knucklehead®,
Panhead®

RooDog
Site sponsor
Site sponsor
Posts: 1770
Joined: Tue Oct 31, 2017 1:00 pm
Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Custom Built Evo 100" Bagger
Location: Knoxville, Tennessee
Has thanked: 793 times
Been thanked: 669 times

Re: Spark color and s&s jetting... another time...

#13

Post by RooDog »

James has one of the worst, and hardest sites to navigate, and with a minimal amount of information. I may just as well be on the J&P site....
Or I'm just really incompetent....
....RooDog....

Teo87
Posts: 13
Joined: Sat May 18, 2019 10:51 am
Bikes: 63 panhead
Location: Piacenza
Been thanked: 5 times

Re: Spark color and s&s jetting... another time...

#14

Post by Teo87 »

unfortunately the leak is not from the "o-rings" but from the manifold ... where the "T" pipes cross, precisely halfway between the corner and the "s & s" writing (towards the front cylinder) I saw well the white bubbles of soap that grew ... I cleaned and checked several times ...
in another discussion, I believe user Cotten posted a photo indicating the collector's weak spots, and it was one of them. I followed his guide to test ... (I've been writing recently but I've been reading the forum for 3 years! and thanks to you I have already solved many problems :D)

http://virtualindian.org/11techleaktest.html

the "o-rings" are in Viton by s & s ... by James I find them only in rubber ...
when I bought the new ones I took 4, for safety I have already tried to replace them but nothing changes ...
the silicone for high temperatures I tried to use it thinking it was helpful ... now I reassemble them without ...
maybe it's that hole that gives some carburetion problems ... or running without a filter and without a muffler ...

forgive me, I ask you another thing, which collector do I buy? s & s or Harold?
harold promises a better flow and is much more robust ... but I would not want to throw all this money for nothing (250 € !!!) ...
https://www.wwag.com/cgi-bin/WebObjects ... =%21132329

Raytag
Site sponsor
Site sponsor
Posts: 116
Joined: Sat Oct 05, 2019 8:09 am
Bikes: 1972 FL, 1975FX Bitsa
Location: Germany
Has thanked: 12 times
Been thanked: 56 times

Re: Spark color and s&s jetting... another time...

#15

Post by Raytag »

Nope Roo
the James website is a f****** nuisance and a complete waste of time.

Teo
the manifold is cracked ? :shock:
Without pics it is hard to tell whether the engine is running lean
With a cracked manifold any other considerations are useless.
Maybe it can be spotwelded with TIG ? Just flame no Tungsten wire
However, I never ever heard of a cracked manifold ...

Ray

Post Reply

Return to “Panhead”