'98 Elite SA50 ECO Build

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burnt_toast
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'98 Elite SA50 ECO Build

Post by burnt_toast »

Hey guys,
Been years since I've logged a project, but no time like the present, and gonna give it another go :coolcruise:

This thread is to chronicle the build process of a '98 Elite SA50 I picked up roughly a year ago, with only 900mi! Prime suspect for some mods no :naughty: Alas, all I've managed to do since is: removed rear cover, slapped in a Kymco ZX50 variator, rode around a few times. But its 2020 and time to get crackin!

I've built lots of scoots before, fast scoots, street stuff, rat bikes; well this one will have a slightly different purpose. After recently buying a '14 Mitsubishi Mirage and getting into hypermilling, the MPG bug has bit. SO I plan to modify and increase performance, but with economy more in mind than previous builds, hence the "ECO" title. To date, my best on Mirage has been an outstanding 49.6 MPG! While the Elite has averaged 53.7 MPG.. barely better! This needs to be remedied. To start: a few vari options, gears and clutch pictured (trusty pup Foxx inspecting for quality of course). With some partzilla gear cover gaskets on the way.

Follow along as I eek out what I can, while staying 2stroke and 50cc. But who knows what future holds. cheers

elite01.jpg
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elite02.jpg
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elite03.jpg
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Last edited by burnt_toast on Wed Jan 08, 2020 5:17 pm, edited 1 time in total.
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Re: '98 Elite SA50 ECO Build

Post by Meatball »

:popcorn:
I need to find some new haters...the ones I have are starting to like me.
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Re: '98 Elite SA50 ECO Build

Post by burnt_toast »

Baseline stats
Intake: stock PA35J carb, stock jets (will verify), stock mani, stock reeds
Exhaust: stock pipe
Cyl: stock bore, stock head
Oil: Castrol Go! 2T (Orielly's)
Ignition: OEM boot, NGK B8HSA -washer +CHT probe
CVT: Kymco ZX50 vari, OEM rollers 6x ~6.5g, back half cover removed, stock belt ~1k mi
Trans: Stock gears, 12.115:1, orig oil presumably 10w40 oem

Prelim CHT readings in current configuration:
1.
ambient temp 51F
cold engine 56F garage
1452mi .842gal 87oct $2.03 2.40/gal
280F max uphill WOT
sub 260F flats WOT
2.
ambient 56F
cold engine 58F
282F max uphill WOT
sub 270F flats lots WOT
3.
ambient 68F
cold engine 63F
281F max uphill post:
269-273F max extended flats WOT ~5mi

Current Performance:
Solid 38/39mph GPS verified top speed, on the flats (42mph recorded, but was after downhill assist)
53.7 mpg avg, over 4x tankfills
baseline_12jan20.PNG
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Goals:
Easy 45mph on flats, 50+mph top speed
60+ mpg avg, hopefully better

Methodology:
Keep fueling stock as possible, as long as temps in check. Upgrade intake/carb later on if needed & beneficial. Modify all else, incrementally.

Without giving too much away, upcoming mods to include:
dual density air filter for stock box
cf reeds, ported intake? if hepful
up gear, chosen ratio to be discussed
variator and driven face, several options
clutch, may not be needed but have on hand
cyl & head mods, but stay 50cc
exhuast, several options
Aero mods oooh.. may be silly
Weight reduction

side bar: if she blows, or i get bored on this path.. have 70cc Corsa and Arrow, both NIB on hand to go hamma time :lol: :lol:
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Re: '98 Elite SA50 ECO Build

Post by Meatball »

Hello Burnt!

PM
I need to find some new haters...the ones I have are starting to like me.
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Re: '98 Elite SA50 ECO Build

Post by Ben L. »

Interesting ideas. I'll be following.

Guess I never realized these scoots get such terrible mileage. I bought a 2011 Yamaha C3 50cc scooter brand new and got a best of 137mpg while averaging 110+ mpg. I know its apples to oranges but a swap may eventually be in order :naughty:
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Re: '98 Elite SA50 ECO Build

Post by inCahoots »

Following, any update since January?

Also, the drive face lock washer, do you have the part number handy for that? I cannot for the life of me find it.
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Re: '98 Elite SA50 ECO Build

Post by burnt_toast »

Ben L. wrote: Thu Jan 30, 2020 4:43 pm Interesting ideas. I'll be following.

Guess I never realized these scoots get such terrible mileage. I bought a 2011 Yamaha C3 50cc scooter brand new and got a best of 137mpg while averaging 110+ mpg. I know its apples to oranges but a swap may eventually be in order :naughty:
Ben, that is fantastic performance! As far as MPG anyway. Indeed a 4S swap is along the lines of what I've considered down the road. Just makes the most sense from a MPG standpoint.

I've since amassed several other active projects, reason for not following up.

Latest mod is 9.8:1 gearing. Something I've always wanted to try. Have usually done 9:1 or 8.44:1 in search of speeds. But the 9.8:1 is simply fantastic on 50cc! Much less lethargic than 9:1 and stock pipe. Still has that pop off the line, almost like stock gears. And hill climbs are a breeze. MPG has almost certainly improved, but haven't checked it. Just don't ride this one enough. At a crossroads of where I want to go with this bike, gas is cheap and mods are fun :twisted: haha
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Re: '98 Elite SA50 ECO Build

Post by micbergsma »

9:1 is 16x42, right? I got that kit and planning to put on my elite along with stock bore and exhaust... planning to upgrade CVT too... should be ok?
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Re: '98 Elite SA50 ECO Build

Post by Wheelman-111 »

Greetings:

9:1 works just fine on 50cc. You might notice a bit of sluggishness just off the line until the clutch is fully engaged. Then the variator does its job after that. The ZX conversion is worth considering if you stay with 50cc.
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Re: '98 Elite SA50 ECO Build

Post by burnt_toast »

Been a while.. :nervous: So here's a long overdue update!! :mrgreen:

A while back, I capped out this bike's 50cc potential at what I will call Stage 1 (see below). This was good for a solid 50MPH gps'd on flat consistently, and returned 59MPG avg routinely. Decent gains from the 38mph top and 53mpg I started with. Really enjoyed this for a whie. Considering back and forth trips were ~10mi worth of backroads with lots of stop and go, and basically %95 of riding at WOT, this seems to be about as good as it gets for a 'performance' 50cc setup. Of course I could tone down the WOT, go slower and probably pick up 5-10pmg.. but whats the fun in that?? :P Also could have used 9:1 or even further to maximize mpg, but losing the bottom end pop and crawling to top speed, not to mention being lethargic on uphills is just NOO fun. Have 9:1 and 50cc back in my TX bike and its 'fine', but def less fun (Arrow on 50cc remedied the fun part on that bike ;), but that's a separate story).

This is an extremely simple and cheap recipe that I recommend for anyone who wants some good pep off line and uphills, but plans to stay 50cc. No other $$mods required. Factor in rider weight, I am about 155#. Can cruise this setup for WOT for miles and not worry at all about overheating.

Stage 1
9.8:1 Straight Cut Upgears (HP4M With Moly 10W40 for gear oil & Jog washer mod)
Keli Variator + SEF Ramp plate, 9g rollers >> (A superior combo to the ZX50 vari I ran at 1st, easily pickd up 3-4mph just by switching to the keli!)
Dual Stage Air filter in stock box, thx noisguy!! https://www.ebay.com/itm/142574702714?h ... SwFSxaBebF
Rear half CVT cover removed
NGK BR8HSA sparkplug
Head gasket removed
STOCK R. Tire 3.0-10

Stock center spring, stock pipe, stock bore, stock carb, stock mainjet. Never worried about temps, because turns out my temps from earlier post were all done with NO airfilter in stock box at all! I'd blame PO, but obviously shoulda done my own due diligence to check 1st. No matter. Saw no reason to go up with mainjet when switching to the Dual stage air filter. Noticed the headgasket was removed also at dissassembly, so wasn't an actual mod 'I' did per say. But it could factor into the overall performance, since small compression bump. Regardless, always ran 87octane on this setup. YMMV

Interestingly, it was my next 'mod' that forced me right along into pursuing "Stage 2". I'll explain. I was already geared out at speed and really liked these 9.8:1 gears, but there's more than 1 way to skin a cat right? Another side project I picked up ('87 SE50), had 2X brand new rubbers and BOTH were 3.5-10! Aha, I swap tires and throw that bad boy on my ECO Dio proj and get me more gearing!?! In theory anyway.. Well, I did just that. Rear tire was due for an upgrade anyway, perfect. And the results..

Same top speed!! Also same MPG. BUT now notably more sluggish in launch and midrange :? Which are exactly the characteristics I'm raving about over here talking about the 9.8's paired to 50cc. Imagine this affect to getting the sluggishness of the 9:1gears on 50cc, without ANY of the actual speed gain. The only, and I mean ONLY time I could feel a benefit from this rear tire mod was going down a very very steep hill, could push me up slightly higher top speed. But everywhere else, 90% of time or more it was a total let down. The rear tire weight is just too much! Pretty sure I recorded the weight difference, will try to post that back when I can reread my logs, for science :) lol

The subpar 3.50-10 rear tire results forced my hand. Mpg be damnd. It's time to go 70cc!! This is where Stage 2 begins. Currently breaking in and tuning. Focus will still be to sip fuel, but move out at a more rapid clip. More details to come 8). Thanks for reading.
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Re: '98 Elite SA50 ECO Build

Post by burnt_toast »

for science, tire swap from 3.00-10 to 3.50-10 resulted in +0.8 lb. overall gain. Seemingly low, but apparently significant when at 50cc power levels.

pro: more sidewall = comfier ride.
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Re: '98 Elite SA50 ECO Build

Post by burnt_toast »

Stage 2 has been a mixed bag. Much more fun to ride!! But a harder hit to MPG than anticipated.. Let me break it down.

Stage 2
(All Stage 1 Mods)
-BR8HSA sparkplug
-3.00-10 R. Tire
+
Polini Contessa 72cc Bore kit, chamfered ports, used piston (cleaned up)
NCY Exhaust
Stock carb, needle 1clip richer, 84main jet
Auto-grade fuel/vac linees, in-line filter & ON/OFF valve
B8HS sparkplug
Gutted air shroud
Oil pump zip tied full open + ~70:1 premix in-tank/gal
6x 9.0g rollers 54.5g ttl (actual)
3.50-10 R. Tire

Still stock clutch, bell, center and springs. Big shout out to member bonesv for hooking it up with the used piston to complete this kit! Kit came off a parts bike and the original piston was severely damaged by PO. bonesv sent me some used pistons that had seen better days, but with a friend's help, wirebrush/sander, some elbow grease and time, cleaned them up to be useable. Ah 2stroke simplicity and durability, gotta love it. :love:

Broke in proper with 10+ heat cycles, kept stock pipe on for that. Monitoring CHT temps and added a cheap tach. Current Vari weight tuned to rev 7.6k rpm on flat, just under 7.8k peak power point of the Contessa kit. Translates to excellent pull all around, once on the pipe. Impressed with the NCY performance, while 'V8' variant was just okay in past, this NCY actually hits a noticeable powerband. Diggin it. And 3.50 R. tire weight no longer an issue, plenty of grunt now to overcome it.

Did have some snags running at WOT, tried up jetting, worried it was soft seizing, but turns out it was fuel cut. Also turns out "stock" carb is actually a china copy, hence the mystery main jet from much earlier. Traced fuel cut to the float and fuel valve. Float was too large and limited flow and fuel valve blocked off more fuel at higher flow rates, likely. Swapped in some OEM internals from a spare carb and fuel cut solved! Runs great WOT in almost all conditions, and seeing temps of 350-365F max. Only at WOT down extended hills and holding max speed has it hit fuel cut again, and have a fix in mind for that at Stage 3. But won't get ahead of myself. What's the #'s for Stage 2??

60MPH Gps'd top speed! On flat, with tuck. No tuck is 57. And pulls up strong nearly any hill at 50mph regardless of grade or wind :D (thx 9.8 gears). Launch is good too, but A/F needs work as its boggy down low (rev up and brake launch are the trick for the moment). Will tweak that later.

Quite pleased with this level of performance considering basic bore/pipe combo. But the MPG, suffers.. 41.8 MPG :shock: avg over 5x gas fills. It's so much more fun to ride now at 72cc that I don't really mind it too much, but believe I can improve on it. Swapping to lower ratio gears would be the no brainer, but for time being want to push some other efficiency tweaks via better thermal management etc. Some more tricks up my sleeve, for Stage 3 :twisted: But if all else fails, keeping gear swap as an open option. With that, back to the garage :hi:
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Re: '98 Elite SA50 ECO Build

Post by burnt_toast »

A few pics of the progress :)
Contessa vs Stock bore
Contessa vs Stock bore
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NCY vs Stock pipe
NCY vs Stock pipe
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20210503_205300~2.jpg
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Re: '98 Elite SA50 ECO Build

Post by burnt_toast »

Capture+_2021-06-16-17-42-02.jpg
Capture+_2021-06-16-17-42-02.jpg (45.05 KiB) Viewed 7466 times
Note, noticed boost port had a huge booger glob of case sealant left over from original manufacture. Easily covered 50% area, and probably the easiest thing to fix while I was at it. Probabbly what kept me from getting 60+mpg in 50cc guise... :lol: jajaja
20210403_191509.jpg
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OEM vs China float & fuel valve
OEM vs China float & fuel valve
20210612_104000.jpg (132.68 KiB) Viewed 7466 times
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Re: '98 Elite SA50 ECO Build

Post by burnt_toast »

It has been a long time with no update! Apologies for that. The scoot sure has evolved since the beginning.

It blew up after about 300mi on the last post Stage2 setup. Or so I thought. Dissassembly showed that the piston rings got stuck (on exhaust side I believe) and blow by was so severe that compression suffered. This makes sense, as I was trying to re-use a badly worn contessa piston that was just polished and cleaned, but very likely out of spec.

I went ahead and built back up with nearly the same setup, but this time a brand new-in-box Contessa kit! And a few more goodies, listed below. This new "Stage2+" setup has been dogone reliable for about ~1800 miles or so, with CHT readings peaking at 389F once, and sub 370F on most rides, 355-365F on average. WOT thru-out.

With this latest concoction, top speed stays the same at 60mph GPS. Typical cruise at 55+mph on flat, and still that * hole shot. But now a more respectable 55mpg average! Much much better :smile:

Biggest difference to improve MPG was switching out the china-copy stock-like carb in favor of an OEM Honda carb. Although they look identical on the inside, after lots of riding, trial and error, it was clear the china-copy was leaking! And hence the poor MPG performance of the previous post Stage2 setup.

For fun, the full Stage 2+ modlist:
Polini Contessa 72cc Bore kit
chamfered ports, mild exhaust port
mild intake case port
NCY Exhaust
Stock *OEM* carb, needle 1clip rich, 94main
Stock airbox, modded: 2nd intake slot punched out
Dual stage high flow air filter
Auto-grade fuel/vac lines
high flow in-line fuel filter
in tank strainer deleted
Custom Fel-pro intake gaskets
Polini CF reeds
NGK B8HS sparkplug
Gutted air shroud
Trailtech CHT
Oil pump zip tied full open
Castrol 2T injected
+70:1 premix in-tank/gal Castor927
Keli Variator + SEF ramp plate
3x9g+3x8g rollers 52.3g ttl (actual)
TFC Aluminum outer driveface
9.8:1 Straight Cut Upgears (HP4M With Moly 10W40 for gear oil & Jog washer mod)
Malossi Winged clutch bell
Stock clutch
Stock springs
Daytona Showa R. shock
3.00-10 F. Michelin S1
3.50-10 R. MMG Tire

Will post up some pics, next post. cheers
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