Board index Flathead Power-Technical Questions, Answers, and Suggestions Pans S&S P93

S&S P93

Post Wed Oct 19, 2016 3:26 am

Posts: 10
P93, runs well, starts on kicker and electric ok.
After warm up, enricher off, engine drops back to idle and seems to drop rear cylinder. Soon as I bring engine above idle, rear cylinder kicks in.
At idle rear cylinder seems to fire randomly and not often, engine runs fine other than this idling issue.
Faulty coil? Could voltage be an issue with electric ignition, problem seems rpm related?
Charge light flickers at idle, brand new CE generator, but is the low amp 12v version I think.
Any one seen this with the P93??

Post Wed Oct 19, 2016 3:15 pm

Posts: 1204
Location: Ojo Caliente,NM,USA
Intake air leak?
Dusty

Post Wed Oct 19, 2016 9:09 pm

Posts: 10
don't believe so, everything seems tight and leak free. have not done a comprehensive leak test though.
Engine is new, done around 1000 miles.

Post Thu Oct 20, 2016 8:02 am

Posts: 3322
Location: Central Illinois, USA
Welcome Stix, again...

I forgot to add in my reply to your intro post:
"Never does only one thing go wrong at a time"....

If your timing, valve adjustment, and all other things are in order, then a thorough test for vacuum leaks is in order: http://virtualindian.org/11techleaktest.html

Testing while assembling will alert to overtightening of the clamps.
Please be certain that you have a secure mounting bracket to support the carburetor assembly.

Beware also that S&S manifolds are not immune to casting porosities:
S&SPORE.jpg
Forgot who to credit, sorry.
S&SPORE.jpg (31.68 KiB) Viewed 3175 times
S&Spore2.jpg
Forgot who to credit, sorry.
S&Spore2.jpg (95.02 KiB) Viewed 3175 times

So please be thorough,

.....Cotten

Post Fri Oct 21, 2016 3:19 am

Posts: 10
Cheers for the advice and link Cotten
Leak test will highlight or eliminate, I'll get onto it

Another thing I'm interested in, peoples thoughts on the S&S electronic ignition and pro's/cons of converting to points.
How would a shed mechanic like myself go about fitting a points ignition, what bits would I need if going down that road.

Post Sun Oct 23, 2016 11:03 pm

Posts: 21
Location: Snohomish Co., WA
stix wrote:
Another thing I'm interested in, peoples thoughts on the S&S electronic ignition and pro's/cons of converting to points.
How would a shed mechanic like myself go about fitting a points ignition, what bits would I need if going down that road.
I don't know about the S&S electronic ignition, but I've been running an eBeyond electronic ignition setup for the past 4 years in my 48-ish Pan (with '55 engine), and I'm very happy with it. I switched from a points ignition to electronic, and the changeover was pretty easy, so going the other way would be pretty easy, as well. All I needed to do was to remove the points and condensor, and the long wire going to the coil. After that, I installed the sensor on the timer plate and mounted the magnetic doodad on the timer shaft.

If you go with a points ignition, you'll almost certainly need to change the coil -- electronic ignitions work with coils in the 3 ohm range, while points ignitions work with coils around 5 ohms, if I'm remembering things correctly. When I changed over to electronic ign., I changed my plug wires, as well, following the advice of the manufacturer, to shielded wires. If you're running points, you don't need to worry about the electricmagnetic field that surrounds solid-core wires.

Pro's of points
They're lots cheaper than electronic ignition components,
You can always carry a spare set of points/condensor in your tool kit,

Con's of points
Quality of condensors - some brands fail right out of the box,
Points have to be checked for adjustment fairly often.
If the condensor fails, your points won't last long.

Pro's of electronic ignitions
Once they're in and the timing is set, you don't have to do anything more to them.
Many people report that starting is easier (that was the case for me as well).

Con's
If the diode in the sensor craps out on you, you're stuck, unless you happen to have a spare sensor with you, which almost no one does. I've had excellent results with mine for the past four years, though. Excess heat inside the spark timer seems to be the major killer of these things.

Post Mon Oct 24, 2016 7:35 am

Posts: 3322
Location: Central Illinois, USA
Mark44 wrote:
Many people report that starting is easier (that was the case for me as well).
Golly Mark,

You mean you can start it with less than one hot kick?

(I watched a fellow turn his warmed motor over to just the right place where he could open the points with a screwdriver, and the motor just started running like it never stopped.
I have never, ever been able to reproduce that.. )

....Cotten

Post Fri Oct 28, 2016 5:10 am

Posts: 10
the S&S timer runs with reverse gear drive, would a points conversion require to go back to conventional gear drive direction
or will points still time the same no matter what direction i spin them.
In other words, can I just add advance mechanism and points plate, re-time and away I go.
My limited knowledge tells me i may need to change out the gear drive in the cam chest, just trying to confirm this.

Post Mon Oct 31, 2016 9:19 am

Posts: 21
Location: Snohomish Co., WA
Cotten wrote:
Mark44 wrote:
Many people report that starting is easier (that was the case for me as well).
Golly Mark,
You mean you can start it with less than one hot kick?
When I first got my Pan five years ago, it was very difficult to start, especially cold, but sometimes when it was warm, as well. After switching over to the electronic ignition, it was a lot easier to start. My WL is another story -- two prime kicks and one or at most two kicks with ignition on, and it fires up.

I've heard some people say that the flatheads start a little easier than the OHVs, which certainly seems true in my case, but I have no idea what that might be true in general.

Once the Panhead starts up, it runs great -- lots of power -- but it rarely starts with one kick (plus a couple of prime kicks before). And after it has run for awhile, it starts pretty easily.

Post Mon Oct 31, 2016 10:42 am

Posts: 3322
Location: Central Illinois, USA
Well Mark,

With all things in order, the only difference between the Flatty and the OHV should be the oomph needed to push it through.

If OHVs weren't able to be tuned for one kick, police departments around the world would have ignored them.

Back to Stix's issue, it baffles me why any timer would be designed to turn backwards, and how they did it!

....Cotten

Post Thu Nov 03, 2016 1:40 am

Posts: 10
information i have gleaned from others to date about my questions
S&S timer with reverse drive is ok to use, just replace electronic ignition with a 70's cone shovel advance plate, weights and points plate re-time and away we go.
So I'll start gathering parts and see how it goes.

Post Thu Nov 03, 2016 12:24 pm

Posts: 3322
Location: Central Illinois, USA
Stix!

Did it already have a points-style advance cam?
If it needs weights, won't it also need springs?

Frankly, I would keep the S&S unit intact on the shelf, and find a complete '66-'69 OEM auto-advance timer.
The advance cam has a different profile, and a whole lot more friendly.

....Cotten

Post Fri Nov 04, 2016 1:50 pm

Posts: 3322
Location: Central Illinois, USA
Golly Stix,

I just stumbled upon a Shovel advance plate in my scrap bin, and its at least 3/16" or more too big to fit in any pre-'70 timer I've encountered.

If the S&S is that big, it might not be removeable without removing the head!

....Cotten

Post Fri Nov 11, 2016 7:05 am

Posts: 10
Parts will be here in a few days, 1970 shovel advance and points plate with bluestreak points and condenser.
Will let you know the outcome.
P93 has Super Stock ignition from factory in the genny style timer, same ignition that fits in the cone shovel, so I'm fairly sure it all should fit without changing timer housing.

Post Wed Nov 16, 2016 10:37 pm

Posts: 2718
Location: Los Angeles, CA
The MoCo has designed the new FI engines to drop the rear cylinder at idle. Perhaps S&S has followed suit?

Post Fri Nov 18, 2016 5:06 am

Posts: 10
job complete
70 Shovel advance & points plate, blue streak points n condenser,
took 1 hour to fit and static time, bike started first kick, idle is restored to both cylinders.
I'm converted to points forever now.
Image

Post Sat Nov 26, 2016 1:31 pm

Posts: 3322
Location: Central Illinois, USA
Stix!

Does the cover clear the cylinder fins?

....Cotten

Post Sun Nov 27, 2016 2:06 am

Posts: 10
yes mate
Didn't have to change the timer housing from S&S OEM, just pulled the super stock ignition and fit the advance and points plates.
As a side note to this now, when pulling the VOES system off today, the vacuum hose had rubbed through, so obviously that was not helping the cause in any way.


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