Sunday, September 20, 2020

Sunbeam S7 Deluxe - Oil Pressure Switch

 The oil pressure light has not been extinguishing on the Sunbeam S7 Deluxe.  I removed the switch and put some pressure to it, which did not open the contacts.  The stamp mark on the body of the switch is 10psi.  I was well above 10psi air pressure and the switch did still not open.

Figuring that there are replacement switches available, it would not hurt to try to take this one apart to see if it was repairable.  The switch was not leaking oil, so it seemed reasonable it may be just something with the contacts preventing it from opening at the correct pressure.

The adjustment pin has a slotted head inside the electrical contact stud and would not move.

There is a pressed sheet metal collar around the switch body.  I put it in the vice and began prying at the collar.  It eventually slipped up over the switch body and exposed two cutouts with a view of the contacts.  The diaphragm pushes against the outer contact which lifts it from the fixed contact.  The fixed contact was initially factory set at 10psi, and then fixed in place with a center punch mark.  This explained why the adjustment would not move.

After cleaning the inside of the contact chamber with contact cleaner, I was able to see it operate.  Using two small flat bladed instrument screwdrivers, I could hold the fixed contact against the adjustment pin and slightly bend the profile of the contact.  A few iterations of this yielded a nearly perfect contact break point just around 10psi.

The tool I'm using in the video is a continuity tester.  It has a small buzzer and battery in series.  The pointer end is connected to the buzzer and the other side of the battery is connected to the wire clip lead coming out the back.  I built this long ago for general electrical testing.

(Forgive the state of the workbench, I usually don't leave it that dirty.)

If it continues to act up, I will probably order a new pressure switch.  For now at least I know how the original switch works.

I fitted a tee to get the oil pressure switch out into a little bit of cool air.  I'm told that will lengthen the life of the switch.

Thursday, September 3, 2020

Additional Cooling for the Vespa PX engine

 My friend Bill installed Stella Auto cowls on his 2 stroke Stella shifty.  These are vented cowls that maintain a tasteful original look.  The Auto version of the Stella was only imported in small numbers in the United States (300 I believe) and parts are not readily available.  The claim was that additional engine cooling helped pull fresh cool air into the engine compartment to be available for the fan.  The engine does run cooler with no cowl at all, so any advantage is a plus.  Bill was seeing 15 to 20 degrees cooler cylinder head temperature.  That is an advantage I could use!

 I don't have the means to cut louvers or vents into the original cowl and make them look have decent.  The original cowl on my bike was damaged in a crash before I bought it.  The body filler and stickers make it look presentable today.  I do have a square sheet metal punch that is slightly smaller dimension than the checker tape on the lower part of the cowl.  This gave me an idea that I thought was pretty brilliant.  If I cut square holes in the center of a few of the black squares of checker tape, the holes wouldn't really be noticeable.  The additional airflow should be exactly what is needed to give the additional cooling.

The final carburetor settings after all the modifications DR177 kit, SITO+ exhaust, UNI foam air filter come out to be:

Stock 20/20 carb
40/120 idle
160 air
BE3 atomizer
106 main jet

I take the same road over Reesers Summit every Wednesday to meet up with the Three Mile Island Scooter Club.  This road run is the temperature test bed to prove if I knocked holes in the cowls for any good reason.

CHT without holes = 315 °F

CHT with holes = 306 °F

Stella PX DR177 kit

I may have mentioned in a previous post that always wanted a Vespa PX, but due to pressures of my biker friends that nothing less than 500cc's was going to keep up with them, I avoided purchasing scooters when they were at their height of popularity when the PX was re-released in the early 2000's.  When this wrecked Genuine Stella 2T came available locally on craigslist, it was too cheap to pass up.  That combined with my recent career move to a job closer to home, the time was right to jump into the scooter world.  Wrecked and abused, she served well for about a year or so.

The crank big-end bearing failed in a catastrophic manner.  Though she got me home that night, it was time for some major upgrades.

Night Flight

A red scooter is the best way to get around,
No other transport is finer that I have found.
A tank full of fuel will take you so far,
To visit with friends or hang at the bar.
After a dinner, its homeward we go,
Travel is pleasant its like we're on show.
Engine burble turns heads, like they've never seen,
So beautiful a cherished painted art scene.
My Italian-descended tibutation in style,
Nothing of late could bring such a smile.
A pinging was heard; whatever to do?
A loss of compression would surely ensue!
Darkness it came and I filled with dread.
It wasn't far to get back to the shed.
Coaxed up the hill giving all that she could,
The crest was ahead; I felt that we would.
Then plunged into darkness; nothing to see,
But a green lamp on the dash shining at me.
Off with the key and in with the clutch,
If I hit a tree, I'm sure it'd hurt much.
The whispers of wind was all that was heard,
The engine had died, and I uttered a word.
Word of complaint ruined my ride,
The headlamp was out! I could'a cried.
Some short distance more under the tree,
The moonlight provided little to see.
No push was needed; she showed such pride,
And that was the end of our valiant ride.

The search for more power is an ongoing effort when you buy a vehicle to rebuild.  I had already fitted the Sito+ exhaust fitted and re-jetted at the time of crank failure.  The logical step was to either buy a 200cc engine or do a kit for more cubes.  In a way it would have been easier to just drop in a ready-built engine, but where is the adventure in that!  I decided on the DR177 kit.  David at Scooter Mercato was a big help in making the right choices for good reliability and more torque.

First, let's say that the PX engine is a NASTY dirty thing when it is abused or neglected, whether it is an Indian or Italian engine.  The gearbox breather sits atop the engine.  The breather is capable of producing enough oil mist to cake the cases over time.  The overflow from the carb should not be a real issue, but it is something to watch.  I abhor dirty engines and oil leaks.  When I heard that most folks stand by the age-old grease on the gaskets approach, I was appalled.  Engines should be built to stand the test of time and not leak.  So after spending DAYS of scrubbing down this filthy mill I vowed to keep it clean.  That meant when it was time for re-assembly I was going to use Permatex "Right Stuff" and spray-on Gasket Sealants.  Whether it was needed or not, I also ran a road tube from the gearbox breather to the back of the engine.  It can't hurt to keep things cleaner.  The other addition is an exhaust spoon.  This is a piece of 1" stainless tubing cut out and cold-formed in a spoon shape.  The end clamps to the exhaust stub and is held in place with a hose clamp.  The idea is to re-direct the oily exhaust away from the rear tire without changing the dynamics of the 2 stroke exhaust chamber.

Another requirement was to keep the autolube system.  I hate mixing, the thought of having to mix oil every fuel stop was not something I ever wanted.  The autolube system is a technological innovation that I believe in.  Since the jump from 150cc to 177cc isn't a big one I figured that things should be lubricated just fine.  I usually dump a little Marvel Mystery Oil in anyway, so a little extra oil should be just fine.  The problem was that the 2009 year LML autolube carb box had a machining issue which would allow oil to go past the check ball and fill the crank chamber with a large charge of oil.  That would result in a large embarrassing cloud of smoke in the morning.  I tried to overcome it on my own, but if I was re-building the engine I didn't want to take any chances.  SIP shop had replacement autolube carb boxes available, so I bought one to put on.
(oh yes, I did!)

Since I was re-jetting anyway, another easy modification was for a more free-flowing air filter.  The white and blue material of the original was all oil-contaminated, so cutting it all off was an easy choice to make.  I had some leftover UNI filter material left over from a previous cycle overhaul.  That was easy to cut into the right diameter loop and slip over the original air filter frame.  It was cut the right shape to completely cover and insure good filtration with the best air flow possible.

The only thing I didn't change was the reeds.  The LML reeds seemed good, so I just put them back on.  This may prove an easy upgrade later.  Goodness knows with all the carb jet experimentation that I've done, going to a bigger jet is as easy as looking in the box of spare parts that I already bought.  So for now the original reeds should do.

After MUCH experimentation, a lot of reading other's accounts of what carb and jets they were using, I settled on the following.  This is based on plug chops, and cylinder head temperature readings.  The TrailTech gauge is battery powered and easily attaches to the glovebox on the scooter.  The wiring had to be extended to reach the whole way back to the cylinder, but that wasn't much of a problem.  Observations were that when the engine was running rich, the CHT gauge would read very low.  If it was too lean, of course the CHT readings would be too hot.  The trick was to find the happy medium of Main Jet that yielded a middle CHT reading without going too far above 300°F on a hard pull.

Stock 20/20 carb 
40/120 idle, 160 air, BE3 atomizer and a 106 main jet.
19° BTDC ignition timing.

Wednesday, July 8, 2020

Sunbeam S7 Deluxe Chronometric Speedometer - Temporary Substitute

The speedometer has not worked reliably on my Sunbeam S7 Deluxe in about two years.  It would work on and off, then finally it quit altogether.  It needs to be properly rebuilt.  With stories of other folks overseas shipments being quarantined or lost in customs, I did not think it was a good idea to send it to England for repair.  Sure there are proper aftermarket replacements but they cost over $300 USD plus shipping and they still need a cable and hall-effect pickup to function.

I had been just dealing with the lack of speedometer, and I wasn't actively looking for another solution.  Fortunately here in the USA if we register as an antique there is no safety inspection or MOT.  Sometimes targeted advertising is actually a good thing.  In my news feed of a popular social media up popped an advertisement for a GPS Speedometer.  Brilliant!  Why didn't I think of that!  It needs no cable, just power and a clear view of the sky.  The antenna could be hidden anywhere on the bike or just strapped on with tyraps in plain view.  It would look plain and not unusual unless you really looked hard at it to find the digital display.

Nobody makes a GPS speedometer for an 80mm diameter speedometer bucket.  They are all 65mm or 85mm.  My grandma used to say "Can't is a coward", meaning if you think you can't then you are already defeated.  There must be a way to fit a 85mm speedometer in a hole for an 80mm unit.  I bought the speedometer for the modest asking price and resolved to figure it out.
ELING MPH GPS Speedometer Odometer 140MPH For Auto Motorycle With Backlight 85mm 12V/24V

Upon arrival like any good engineer, I took it apart to see how it worked.  The mechanism was simple.  The bezel pried off easily exposing the bucket with the speedo unit inside.  Two screws in the back removed, and the speedo pushed out of the bucket releasing the power connector inside.  Another connector went to the GPS receiver hot-glued to the bottom of the bucket.

The plan was to cut the speedo bucket so that half was above the headlamp and half was inside.  I would then contrive a way to join them back up.

Luckily there is just enough room around the edge for some stainless steel sheetmetal.  The sheetmetal was fastened carefully to the inside of the bezel and passed along the inside of the speedo bucket.  It could then be re-attached by drilling a hole through both and allowing the sheet metal to self-tap.

All assembled, but there was naturally another challenge to overcome.  My bike is 6 volt positive ground and the speedo needs at least 9 volts.  No problem.  I bought a boost regulator and set it for about 12 volts.  It gets powered from the original speedo backlight and there you have it.
MT3608 DC-DC Boost Power Converter

 One night's worth of work and I have an operational speedometer.  I can take my time getting the original rebuilt and nothing on the bike was done that couldn't be reversed.  A big fat o-ring from a spin-on oil filter covers the bottom of the bezel which had to be thick enough to support putting four screws in it.  The o-ring could be backed with some RTV if I thought the bike was ever going to get wet... which it usually doesn't.

The maximum speed is a bit optimistic.

Thursday, March 14, 2019

Feel the Love. It's Genuine.

In keeping with our tradition here of getting into something after its already been mainstream-cool, consider the scooter craze of several years back.  Mainstream-cool is like a fad and different than Always-cool.  Sorry, scooters will always be cool.  Remember when gasoline was $4 a gallon and scooters were all the rage?  Today you don't even really see many scooters.  At the height of the fad, I was totally in love with the Genuine Scooters model Stella.  They had just released the 4 stroke version and were developing the automatic.  My heart was with a Vespa-compatible 2 stroke however.  It was hard to justify since the barn already included a couple motorcycles.  So the lust for scooting was forgotten, until recently.

2018 was a year of unrest.  I changed jobs which resulted in an 9 mile commute, instead of the +30 mile commute that I was previously enduring.  This changed everything.  No longer would I have to travel the highway, and owning a scooter was well within reason.  The lust for scooting was renewed and the search was on!  I found a low mileage 2009 Stella 2T that had been laid over.  The bodywork wasn't too bad and the mechanical repairs were easy.  With a price tag less than $1000, how could I go wrong?  Plus what is the fun of buying something off the showroom floor!

The LML Star / Genuine Stella is an Indian made version of the Vespa PX150.  The parts are interchangeable, and this gives Stella a big advantage for longevity for the future.  The fit and finish is actually pretty good and I was satisfied with the new Stella scoots I had seen on showroom floors.  We can rebuild her... again and again if needed since the parts are interchangeable.  The PX engine clone was sold between 2003 and 2009, but the LML engine was reed valve instead of rotary.  Since LML stopped producing the Stella line, the logical choice was the 2T.  The four stroke and automatic at this point can't be expected to be supported very well.  I love an orphan vehicle as much as the next guy, but there's no point in subjecting oneself unnecessarily.

Key Specs
* Engine: 150cc 2-stroke, air-cooled single
* Power: 8.0 HP @ 5500 RPM (2-stroke)
* Transmission: 4 speed manual
* Bore & Stroke: 57.8 x 57.0mm (2-stroke)
* Fuel Delivery: Carb
* Wheelbase: 48.6”
* Weight: 240 lbs (2-stroke)
* Starter: Electric and Kick
* Seat height: 32.3”
* Fuel Tank: 2.1 gallon
* Oil Tank: 0.26 gllon
* Front Brake: Hydraulic Disc
* Rear Brake: 6” Drum
* Front Suspension: Trailing Link, Gabriel
* Rear Suspension: Single Gabriel Shock
* Tires: 3.5 x 10” (Front and Rear)

Broken headset, broken headlight, missing mirror.

We picked up Stella from a young fellow in Red Lion.  He was the second owner, and the scooter had been laid over.  The damage wasn't too bad.  I managed to straighten the bend in the leg guard enough to make it reasonable.  A little touch-up paint and some stickers and nobody would know.  The headset casting was another matter, that would need replaced.

 Take it all apart.

Disassembly was easy.  The wiring had to be repaired in a few places, but the damage wasn't all that bad.  The only really difficult part was threading the throttle cable through the body.  A word to the wise, make sure you can pull the new one in when pulling the old one out.
 Remember where it all went.
 Lay out all the parts.
 No one wants things bouncing around in the storage compartment...
so why not line the compartment with rubber from an old inner tube!

The Stella storage compartment is actually quite voluminous.  If the capacity were measured in beers, then a 12 pack would fit.  All it has to do is hold my lunch in the box.  The "curry hook" is perfect for carrying a growler full of craft beer.

 New black headset casting, painted red.

 Pound out the dents and fill in the scratches.

The previous owner made a poor attempt to fix the damage by the crash.  The paint didn't even match and the dents were still in the metal.  I'm pretty lousy at bodywork, but I was able to make it look as good as new.  The whole bike had been de-chromed.  Most of the bright work have been removed, so all that remains is a Red / Black color theme.  The only remaining chrome is the turn signal bezels, the mirror stalks, and front spring fulcrum cover.

 We are all smiles here.

 First trip into work.  Then off to get state inspection.

One thing I learned early on was not to fill the oil tank completely full.  The oil tank is above the level of the carb, but a level too high will overcome the check valve spring in the carb.  That causes oil to dribble down into the carb, and onto the reads where it sits waiting for you to kick start.  When that happens the whole crankcase gets a big mess of oil in it.  That results in the whole neighborhood being covered in a huge cloud blue smoke.  So I only fill the oil a little bit above the sight glass now.

 "Dad, when can we go for ice cream?"

"Stella" was the name of my beloved pet mouse, so I needed to personalize the scooter in her honor.  And I love checkered flags.

 Every bike I've brought back to life has worn an "UNDEAD" sticker.
It is simply the way of mad science.

The major complaint about this scooter was a little lack of power.  In talking to a few people about the 2T Stella design, I discovered that the emissions restrictions placed on this scoot really restricted the potential of the engine.  The said it really wasn't making the full 8 hp.  The catalytic converter is just too much of a restriction.  The amount of oily smoke that comes out of a two-stroke, I was convinced this exhaust was clogged with crud as well.  Upgrade to the SITO+ exhaust seemed like the best balance.  There doesn't seem to be a need to go to a 177 kit, or anything that would reduce reliability.  Something like the SITO+ should have been the stock exhaust from the factory.

 More POWER!

Scooter Mercato stocks all these jets.  (Dave is awesome to deal with and usually ships the same day.)
The SITO+ exhaust recommended re-jetting from stock is:
Carb, Idle Jet 55-160
Carb, Air Corrector Jet, 160
Carb, Atomizer Jet, BE3
Carb, Jet, Main SI 100

The worst aspect of this upgrade was cleaning things up before actually installing the exhaust.  It is possible to carry out this upgrade in an afternoon.

 Installing SITO+ exhaust.

Here's a poor video with the first startup with the SITO+ installed.  She started right up and ran with no problems.  Idle mix was about 3-1/4 turns without further tweaking.  I wish I would have actually timed myself climbing the hill in front of the house with a before and after comparison.  I'm quite certain the new exhaust is very much a performance enhancement.

Rejetted and SITO+ sounds great.

Feel the love, it's Genuine.

Sunday, January 28, 2018

Victor Victrola - IV - with a bent gear tooth

The Victrola that I picked up last year at Kutztown has some damage.  You can see in the video wher the casting was once broken and welded back together.  This was presumably from someone bashing the spindle to try to get the platter off.  The spindle is bent slightly and there's a clicking in the governor.  The bent spindle only makes the platter wobble, and doesn't affect music playback.  The clicking is apparently from a smashed tooth on the gear that runs the governor.  I de-greased and re-greased the entire mechanism, but the tooth is still causing a problem.  Carefully removing the spindle again and filing down the offending tooth seems to have fixed the problem.

The old grease from the 1910's was petrified and had to be chiseled off.  Soaking everything in PCS-1000 parts cleaner helped tremendously.  When I re-assembled it for the final time I used Tribol Molybdenum grease.  This stuff is amazing!  Even if it wipes off or goes dry the Molybdenum gets into the crystalline structure of the metals and continues to provide lubrication.

For your enjoyment a little Harry James and his Orchestra!

What it really needs is a genuine Victor Exhibition reproducer.  The Tip Top that came with it is deteriorating so badly that I dare not remove the screws to replace the seals.  The potmetal is cracked and falling apart.  The search is on.

Thursday, August 3, 2017

Sunbeam S7 Deluxe - Crankcase Breather

I recently met up with a nearby Sunbeam owner from Lancaster County (across the river).  We compared our machines and discussed improvements and modifications.

One thing that my friend noticed was the crankcase breather on my Deluxe.  I wanted to avoid fouling plugs, and a disturbed mixture, so instead of routing the breather back into the air cleaner, I used a road tube.  Since there isn't much opportunity for a "draft tube" like on a car, another method was in order.  The standard breather "check" valves stopped working of course.

I obtained a brake booster check valve from Dorman products and mounted it alongside the frame rail, just above the side engine damper.  Since the valve's inlet port diameter was quite large, it needed to be reduced.  So I put another hose inside that one.  The outlet tube then goes along the frame rail behind the silencer.

The larger port is the inlet, the smaller one on the side is the outlet.
Part #: 80189

The brake booster check valve insures that crankcase is well vented.  The front of the engine stays clean, and the vapors are deposited well behind the rear wheel.