2020 ScootTerre Bistro 50 CVT

[br4inl3ss]

hi all.

this seems to work properly, right ?




checked the sliding pin inside, checked seals, everythign is dead smooth on hands.

i think its fully engaged wayyy too soon. that may explain such high rpm wot ( 9200-9400 ).
contra spring seems stock, and they said 8.5g is stock.

trying to figure out an acceleration issue.

start very strong up to a specific speed, calm down to low 5200 - 6200 rpm ( still WOT ), then past a specific speed it accelerate good again.

i first tought it was a fueling issue... but twisting throttle so the accelerator pump spit gas into the engine has absolutly NO effect at all. but if i abuse then its getting flooded and has to clear up. but thats like 15+ twist. 1-10 twist has no effect at all. its only at a specific speed no matter the rpm/throttle position.

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[br4inl3ss]

yup all that checked/done.
the noise is gone with cover on dont worry about that.

anyway i have way better quality parts for the cvt. i just need to see it running decenly ( so finding the actual cause ) before i put them on. i dont care destroying a cheap stock vario/pulley, but i do care destroying the pricey Naraku racing variator and NCY Dio pulley.

[br4inl3ss]

update
yeah its definitivly the cvt.
went from 85 to 80 mj, no change.
still the same low rpm acceleration.

its still a bit too cold here to spend the day on it but something is bugging me down.

the rollers are 8.5g. stock, apparently. fine. it accelerate at low rpm ( 5300 or so ). thats fine i know i need lighter rolelrs. but it reach 9300 rpm WOT. ive riden over 15 different scooter, and even my mechanical horror didnt reach such high rpm unless i put really light roller weight in. but then thier acceleration was at a more decent rpm range ( aka in the peak torque +- 6800 ) then increased slowly to 9500 10 000 rpm.

this one doesnt act the same at all. rollers too heavy to accelerate properly but too light to limit the rpm to an acceptable level cruise/wot

what am i missing here ? i mean its either too light or too heavy, not both.
or maybe its jsut the clutch engaging way too early ? didnt notice at what rpm it engage, but at idle ( 900-1100 rom ) the rear wheel spin on its own and at a good speed. if thats the case, then that could explain why it feels like the rollers are way too ehavy to accelerate and way too light at cruise/wot.
but 8.5g on a stock cvt setup, gneh. that seems pretty heavy.

anyway. just trying to see if its in good operation order so i keep them when i put my quality parts in ( this week if possible. i miss those parts so much ).


EDIT 

 
I'M *$%&!?$ DONE WITH THIS LIFE
my old scooter aka 2009 Maverick Viron aka mechanical horror.... it killed my quality NCY rear pulley 








the other slide are damaged too, just a little bit less. but its enought that i'm not even sure it can run this anymore.

[GrumpyUnk]

Reaching 9k while on the stand is not the same as on the road, under load.
8.5g sounds heavy to me.
What color is the clutch mumble-forget-mumble spring that pushes the clutch pulley sides together? It may be on the strong side, and squeezing into upper gear ranges too readily.
How did that get damaged? what happened?
tom

[br4inl3ss]

for 9k rpm i'm talking on the road not on stand. i try to NEVER go over 8k rpm on stand and not for long because i know from my car exprience ( mostly good ole american v8 ) revving with no load is very bad.
yeah 8.5 sounds very heavy to me too. but apparently its stock
CONTRA SPRING is stock color aka dark grey. like all stock contra spring.
by hand, is doesnt seems hard.

i have absolutly no idea how this happened. it was on my mechanical horror scooter. that thing killed every parts that could be destroyed no mattef of care level. even if its unrelated. that thing was possessed. plain and simple.

no explaination oh why this scooter was destroying EVERYTHING, but it did. i knew it was strange that it did 2 full run without major problem. damn i knew it ! and thats why, it was silently kiling my beloved NCY honda dio pulley.
i'm literally crying. i cannot buy another one.

but anyway.... to my short experience, if those 8.5g rollers are too heavy and i install lighter ones, the cruise/wot rpm will get even higher... i'll try because it must be done, but doesnt makes sense. my mechanical horror and brother yamaha vino was acting properly on that part = heavy roller means low rpm top speed.

[snaker]

Not a very clear photo, but if that is a divit on the slotted ramp surface, then yeah, its shot.
There's some weird leverage going on there and the ramps aren't going to slide over the pins without hanging up and sticking.
Since its already bad, you could try milling, filing, grinding the ramp smooth and see what happens,
The wider slot would likely cause sloppy banging while transitioning from upshift to downshift, but its already shot?

[br4inl3ss]

i tought about milling it but i just tought the slack would be even wosr than runnign it like that.
anyway i havbe to find a shop that wont ask over 200$ for that job, locally.
they all went full retard for no reason. so much that just doing a porting job they wanted at least 260. pathetic.
didnt call them all tho, just the 4 nearest.
anyway... i used the other slots. they were damaged too but far from this bad.
but it seems to work properly
i installed the ncy pulley, motoforce racing clutch, naraku racing variator, the included 6.5g rollers ( duno if they came with a naraku variator or glixal variator of if its the motoforce rolelr i bought ), and its running decently.
so maybe its fine for a month or two before i ruin myself on a naraku torque driver ?

i have only 2 problems with it right now.
1: this damn racing clutch is too "racing". with soft springs it engage at like 5500 rpm and really grab neat 6200 rpm. that seems high for a 4 stroke.
2: from a stop, when going off, when the clutch grab, we can feel the power of the engine, then rpm drop alot ( like 4000 or so ), then 3-4 "hiccup", then its going as it should afterward.

i also have a carb issue but thats minor since it only happen when we feel the hiccup.
ill try to edit the video i took to post a shot tommorow. or maybe ill forget that too... lol. we'll see.

[snaker]

CVT Torque Sensing (the slot angle) is reactive.
That means the CVT will take off from engagement the same whether the machine has a light load or a heavy load.
Only when the rig starts moving, the TS will sense the extra load and compensate by holding back the upshifting.

So it kind of feels like this:
Normal load:1,2,3,4,5,etc
Heavy load:2,1,2,3,4,5,etc

[GrumpyUnk]

As noted somewhere... Lighter rollers should achieve the same movement of the variator, just at higher rpms, most likely way befoe the 9k figure is reached. I just read that somewhere and it made sense that the variator does not care the grams, it just is more/less aggressive in squeezing the sides together to achieve a final drive ratio between variator and clutch pulley at a lower(heavy grams) or higher(light) rpm, but it WILL BE the same ratio.
OTOH, the 'middle of the range' will likely not be the same, as explained directly previous post...
tom

[br4inl3ss]

there we go with the video.
damn so much better than stock parts !
i probably have a carb issue too.
always WOT on stop-go. what you hear is what happens WOT.



yes the clutch engage high... damn racing clutch ( Motoforce racing clutch aka doppler S2R clone ). its not the brand "Motoforce Racing". its the brand "Motoforce" and model "racing". confusing i know lol. that thing so light even with softest springs it engage higher than id like to. but i have it and thats it.

also notice how it accelerate fast. you guys know those scooter better than me, doesnt it accelerate a bit too fast for a "stock 50cc" ?

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[snaker]

Apr 18, 2024 13:36:05 GMT -5 @jjoshua20214 said:

br4inl3ss:
From reading, it sounds like your carb could not be properly tuned causing a power band issue. You will never be able to tune CVT unless you have your carb properly tuned. Is it stock?

Might be why you feel as if you are "chasing your tail".


Is your top end stock? Because you might wanna start there.
What about your CDI?

When you hit that RPM are you going down hill or flat?

With everything installed properly and assuming the engine case is not somehow mis-shaped, you will have no issues using all new parts.(Unless one is defective)
In my experience a bad clutch can ruin a variator and vice versa. I was wearing my clutches(like yours looked) out from hard accel pulls from red lights to show the car that cut me off they couldn't out run me. (in the city)
I was always using cheap stock clutches though. They were a dime a dozen
Those grooves on the clutch in the picture will cause you to have power band issues you were explaining also.
Those weights are way too heavy, I never used 8g weights in performance engines yet alone 8.5 They come heavy from stock to slow you down for legal purposes. Think of it as a "govenor"
You need between 6-7 gram weights. (Contingent on engine power and final gearing AND RIDER WEIGHT.)
Also, why can't you get another NYC pulley? And how are you sure the damage didn't occur on the other bikes you had it in?

GrumpyUnk:

The "contra" springs ONLY effect when the RPM clutch activates.

Too "stiff" springs will only make tires start moving at a higher rpm.

This can also be done to produce the "burn-out" effect on strong enough engines.

Also, the weight theory may be true. The engine is not powerful enough for CVT tuning to not matter.
More power = heavier weights and vice versa.


Snaker:

There is nothing electronic about these CVT's
The throttle sleave will not "sense" anything and react. There is no shifting involved in a CVT. Hense the meaning "Constant VARIALBLE transmission"
Although it may give off the illusion that it is shifting ONCE as the clutch engages.

Where are you getting this information about how it should feel when it shifts?

Your the only one talking about electronic CVT's
Small engine CVT's have zero connection to electronics

Your the only one talking about throttle sleave's 
Small engine CVT's have zero connection to throttle sleaves

I very clearly wrote that the CVT "FEELS LIKE" manual shifting
Your the one taking that out of context

I truly can't tell if your throwing crap on these posts to mess with the OP's or if you really are babbling that level of stupidity?
Do you know how to read? Do you understand English?

Your comment about the contra spring vs clutch makes no sense as well.
The contra spring and the clutch are two separate components of the driven pulley and have a pretty small association to each other.

[Deleted]

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