Project TaoTao : ATM50-A1 Four-Stroke Experiences & Upgrades

[90GTVert]

The weather still sucks, but at least the sun was out this afternoon. 10-20MPH winds, but they weren't changing direction and intensity so much like yesterday, so I took some test runs. The NCY using 50 degree grooves and a 1K contra spring needed 5.5g sliders to be nearest the cruise RPM I was looking for. The SunL's stock torque driver (49 degree grooves) got closest with 6.25g sliders and the 1K contra spring.

Watching the vids of the gauges is actually easier to diagnose what's up than just test riding, because I don't have to watch the road or cars or whatever. It's pretty clear in them that the NCY does a better job of holding RPM steady. For example, the stock SunL TD is at 7,150RPM @ 20MPH (accelerating) and by the time it reaches 30MPH it's @ 7,810RPM and up to 7,950 @ 34MPH (which has been about my avg cruise with any decent tuned setup so far). The NCY TD using 50 degree grooves is at 7,580RPM @ 20MPH and by the time it reaches 30MPH RPM is @ 7,740 and reaches 7,800 at 34MPH. There's an 800RPM gap between 20 and 34MPH with the SunL TD and only a 220RPM gap with the NCY TD.

I'm still planning on a test ride and 0-30MPH times if the wind ever dies down and it's not rainy or the dew point isn't 1 degree from the temperature... but I don't have much hope of seeing gains in gas mileage or acceleration. More or less I wanna be thorough and see what the difference is in the two. Pretty sure I'll be putting the NCY TD back on. I think this has been a combo of things causing all my inconsistencies. The stock TD does indeed have a spot where it hangs, the variator of course ate itself and the new one even needed different weights to work sorta the same, and the stock spring changed stiffness after getting "broken in" on a 100 degree day. I think the quality NCY TD and the Taiwan made Hoca contra spring will be the way to go, but I'll know for sure on a test ride. Whenever I pick a setup, then I'll stick the Hoca ball bearing base in and see what happens.

[90GTVert]

The weather was good enough for a test ride late last night. I was unimpressed to say the least. Average cruise speed was 32-33MPH @ 7,700RPM, about 1MPH shy of normal. I never tried for max speed because there was enough wind that it changed too much. Pretty sure it would be right on track with others, but perhaps just shy. 36-37MPH. It felt much worse than the NCY setup in town as well, low on RPM until I get to cruise speed. I filled up on the way home and gas mileage was down to 82.5MPG.

I took it out this morning for some 0-30MPH runs. 23.26 seconds average over 4 runs in an area shielded from the potential crosswinds by trees. The SunL TD is a definite no-go. Basically these numbers are all back to very near stock. I think it may be a touch slower from the humidity, but it was about the same when I got 19 second 0-30MPH times with the NCY and slightly better mileage and a little better cruise speeds. I suppose the stocker may do better than at least the SunL TD even with it's wear, but I'm just not willing to cause myself the headaches that wear will create sooner or later in the project. I'm ready to call the NCY TD the one and install the ball bearing base.

Ideally I was hoping to get even closer to the 18 second mark that the setup was at before this, and with 90+MPG, but it just may not happen with any reasonable amount of effort.... and I'm tired of the CVT by now. lol

[2strokd]

Sorry man.. Its gotta feel as if you are wasting time, money, etc. at times..
You are helping tons of folks tho!

Thanks

[90GTVert]

The stock mirrors have been annoying me. I don't really like them in the first place, but I have just left them alone. Now they are loosening up and I have to adjust them more than I should.




I ditched them and installed a bar end mirror. I only use 1 on a scoot, so I had 1 left over anyway from a pair. Now I can actually see past my shoulders and I like the look better. The only real downside is that I have to look away from the road farther to check my rear view, but it's not a big deal and at least I can see what's back there better.




Back to the CVT... I installed the Hoca ball bearing spring base. I applied a thin coat of RTV to the base to help it seal to the torque driver since 2strokd has mentioned needing it on these. It goes together easy. Just take the old sleeve off, install this one, place the bearings, and put the top piece on. My biggest issue is dealing with the ball bearings. I dropped a few at one point and then spent a while looking around the floor. They don't give you any spares, so be careful with them. I measured the ball bearings at 3.93mm, so I ordered a pack of 100 4mm bearings on eBay this morning for $7 shipped in hopes of not spending long periods searching them out in the future.






I took it down the road to the spot I was running the other setups and when I took off it revved out to almost 8000RPM and seemed like it was slipping in, when normally the clutch grabs at about 6000-6500RPM. I thought it was really changing things radically in the CVT for that to happen. I got to a stop sign near my house where I have to cross 50MPH traffic and when I tried to go it went to around 8000RPM and again felt like it was slipping, but this time I was moving really slowly. Luckily I had been suspicious of the clutch after the first time and gave myself plenty of space between cars when pulling out.

I got home and pulled the clutch off thinking maybe softer springs are necessary with the bearing base, but I found that grease was inside the clutch, clutch bell, and coating the inside of the torque spring.










Didn't really look like it was slinging it out of the sides like I have been more accustomed to.




I took it apart and replaced the top seal with one that looked a bit thicker off of the SunL torque driver. I applied a coating of RTV to the base again, and this time I put a very thin coat at the very top of the inside of the base/cover. I let the RTV setup overnight. I cleaned everything thoroughly with brake cleaner and went over the clutch pads real quick with sand paper just to be sure they were good to go.




Made a test pass and the clutch is grabbing as it should now, but I can't really tell you if there's any change at this point. The wind was about 15MPH gusting to 25MPH and the temp and humidity were high so the wideband was even reading rich. I'll have to try again when it's a little better out for a good comparison.

[190mech]

I guess it was the TD slot lube that made it slip?Did you use any lube on the spring base balls?I kinda like dry moly lube on the spring base and vari rollers..

[90GTVert]

Yeah, it's grease from inside the torque driver. I didn't use anything on the base. I'll have to try out some moly.

[grikjames]

Ive stopped using those bearing torque controllers.
It adds pre load on the spring but reduces actual spring tension because it cancels out the torque/twist of the spring.
I think it's more suited for flat roads than mountain passes.
With those installed I feel my bike wont downshift to proper ratio unless I actually slow down then try to speed up again going up hill.

[90GTVert]

The wind died down late this afternoon, so I got a couple of test runs in with the same setup as w/o the ball bearing base (5.5g sliders, NCY TD in 50° grooves, 1000RPM contra, 15000 clutch springs). It's at just under 7,600RPM @ 20MPH (revs still settling from clutch engagement) and by the time it hits 30MPH RPM is @ 7,650 and reaches 7,750 at 34MPH. Very close to the spread without the bearings, but a little less change. It seemed to me that it wanted to cruise a little lower RPM than usual, so I tried dropping to 5.25g sliders. With those RPM is about 7,800 @ 20MPH, 7,880 @ 30MPH, and 7,900 @ 34MPH. Those are sorta rough numbers, because it seems to fluctuate about a bit while staying in that range. If it keeps that narrow rev range it should be a pretty good performer. I think the cruise RPM will be very close or maybe just a touch higher than most previous setups, but acceleration feels better to me. I'm gonna try it out on a test ride and some timed runs this way when I can.

[camogy6]

Wow Brent! I absolutely feel for u. I would just like to say thanks from everyone out there. You are spending a lot extra time/money/aggravation, and just wanted youbto know we appreciate it! On the intake talk earlier, I have drilled holes in my stock box and used a universal filter that is maybe three pieces of paper thick. I had tried open filters, and justbab everything out there. I found that the gy6 like to have some travel between filter and garb. I first tried seperating the stick filter (took foam away and left the more pourus piece. That's how I found this track. Now I'm not saying a uni on the end of the snorkel is a good idea, it'll be worse I think Imo. And I have found that these gy6 engines are soo temperamental with the humidity. Ive actually had to tune the garb multiple time a day because of drastic humidity changes. Just as a thought, did you try leasing with the drive boss washer. I actually put a thinner one in to help acceleration and changed rollers a bit to get a lol more top end power. Just a thought. The only other thing I wondered is if you are still running the blue cdi? It seemed after you installed that is when you had your rpm issues. JW
THANK You again for taking the time to do all of this. I know there are many people that are following this, just may not comment.

[90GTVert]

I never had a washer in my vari.

I took the blue CDI out when I realized something was wrong. A lot of the reason I am trying so much to get it reliable is so I can test out the CDIs and other stuff and not feel like any change is just the CVT being weird that night. I'm doubting my success in that venture at this point, but still trying. I've got even more updates from this (more aggravation) coming soon. I still need to get out there and check something before doing so though.

[camogy6]

OK right on! I just didn't catch that you had taken it off. Ya that is definately the best way to go about it, real life results

[90GTVert]

I settled on the 5.25g sliders and took it for a ride a couple of nights ago to get some numbers. It was right about on target with the cruise speeds, averaging about 33-34MPH @ 7850RPM. It felt really "free" when I got to town and started riding around. It never felt sluggish like some setups had. It actually sounded a little too rev happy at very low speeds, but it felt nice that it was picking up and taking off. I thought I finally had it. On the way home RPM dropped off and by teh time I was about 4 miles out I was cruising 2-300RPM lower than I had been. I stopped to refill 2 miles from my house and when I left it was a little better, and by the time I got home it was back to the low revs of before. 89MPG when I filled up BTW.

I wasn't exactly sure what that was all about. The next morning I wanted to get it out for a ride and see what it did. At times it was at 7800RPM cruising and at times it woudl be at 7500RPM around the same speed. It didn't feel very strong either and cruising speeds were a little sub-par. That ride didn't tell me all I had hoped though, because it was extremely humid/muggy out. Something like 75-80 degrees with no sun out and I was sweating like crazy from the moisture in the air. The wideband was showing richer readings than normal.

I brought it home and decided to go over it and see if there was anything I could find wrong while I waited for better weather. Tire pressures were good, oil level was fine, brakes not dragging, fuel lines and filter looked clean. Dug a little deeper. Valves checked out okay. A compression test showed 162psi with the Actron tester and 175psi with the Snap-On tester. Neither far off of what I saw last time I checked, and certainly high enough to be considered healthy. Here's what the spark plug looks like after 815 miles of good to rich WOT readings.





Notice the peppering on the plug. I have heard a sort of marble rattling sound that I suspected to be detonation at times. I wasn't really sure if it was or not though. I guess it was. It's sort of random, as I don't hear it on every ride or even every other ride. I always use premium, so it makes me wonder if there really is anything to be gained with timing or if it's pretty much at the safe daily limit. That's something we'll find out later though, I hope.

I pulled the CVT apart and it looked decent, but there was a good bit of dust building up on the variator's inner bushing where it rides on the drive boss. Some wear there to match. I cleaned it all up and got the scooter ready to ride again.

The sun came out for a while in the afternoon, and by the early evening it was no longer so muggy like earlier. I took another ride around some back roads. It seemed to do better, but still the revs weren't where they were on my first night time test ride. I also started noticing that it seemed even more free at launch after a while. Nothing too alarming though. I did notice that revs drop some after a while. That's pretty normal from heat, but I hoped a little more CVT venting may alleviate some of my troubles.

I cut a big chunk out of the front of the CVT cover with a sawzall and then some final work with a carbide burr and files. Nothing fancy, just trying to keep it cooler. I do wish I hadn't cut quite so deep so I could have left the saw blade of the fixed half less exposed. It would be pretty awkward to actually get a foot or leg in there with the way the engine sits in the frame, but it looks dangerous regardless.



You can see there's so much stuff up front that there aren't a lot of spots for a big vent.



I took it for another test ride to observe performance and fuel economy after all of this late last night. It looked pretty good again on the way too town. Revs were back up to 7800-7900 on average. Speed was close, about 33MPH avg cruising on the way there. In town it was feeling really free at low speeds and taking off. I noticed that I was hitting as much as 8500RPM taking off and it felt like the clutch was slipping in for a long time, especially if I was at part throttle when accelerating from a stop. It still didn't perform bad in town, just not what it was like the night before.

One the way home it was a little high cruising at first. Something like 8000RPM at 34MPH. It crept up, and by the time I stopped to get gas I had seen close to 8300RPM at 33-34MPH sometimes. I filled up and calculated 85.9MPG. RPM went down a little after leaving the gas station, but was still around 8100RPM cruising the rest of the way home.

This afternoon I tore into the CVT again. I found grease under the clutch bell when I removed it.



You can see below that the RTV gave up and let the grease fly.



Not a whole lot of grease left in the torque driver. I left it kinda low on grease by my standards after the leaks before, in hopes that it would remain sealed easier. Obviously it still didn't work.



That would explain the slipping on launches and really slow speeds. I didn't see any greasy or oily residue on the faces of any pulleys. I really didn't see anything that I can say caused the increase in RPM for sure.

Once again, after maybe 50 miles since the previous cleaning, I found a good bit of dust in the variator. You can see it built up on the lip here.



What really worries me is looking at the wear inside of the drive boss.



It's not that the wear seems terrible right now, but it seems to me that it's forming a very similar pattern to the one that failed very recently. Look at the pic above and compare it to the one below of the failed variator. Tell me if you agree or if I'm way off with my thinking.



With the variator wear, vibrations at speed (I'm still also suspicious of tire balance on that one), and crank sealing issues, I'm getting more nervous about the possibility of the crankshaft not being true. Not seeing any signs on the flywheel side, but I don't think that means much.

For right now, I think my next step is to ditch the Hoca ball bearing base. It's not doing enough that it's worth dealing with more leaks. Seems like a good idea, but the execution sucks. Perhaps it would seal better on a stock TD than this NCY? Not sure, but I can't say I'd rush to buy another one. It's really tough for me to tell anything about performance for sure ATM with so many fluctuations occurring.

So, step 1 is back to a standard base and clean everything up. Step 2 will be to see what sliders want to work out for me now. Maybe I will get back to normal then, maybe things will continue to do seemingly whatever they please, maybe more parts will fail before I get that far? Part of me wants to give up on this engine and get a whole new replacement. A big part of me would rather keep $350 and not do that, but I'm fearing that it's wishful thinking to believe something isn't wrong somewhere else at this point. I know the cases have taken some abuse from so many seal repalcements. By the time I think about a new crank and a new big case half while I'm at it, a whole new engine starts to seem reasonable. Then again, I can't say I've had any issues with the top end, gearbox, stator/flywheel side, etc... I'm not exactly sure what I wanna do... well... what I wanna do is have a consistent pretty much stock CVT... but again I don't know if that's gonna happen right now.

I had to make sure I got this update done tonight. While I was cleaning the CVT this afternoon, I sprayed the case with brake cleaner to get the oil from the leaky seal out. One tiny little droplet bounced back and landed on the lens of my glasses. I pulled them off and when I wiped it the lens cracked and continued to crack for a couple of seconds. I'm staring at a blurry bar in front of me. Tomorrow I'll have no glasses at all because I need someone else to drop them off since I can't really get out of the house. If I reply strangely to anyone tomorrow, it's probably because I can't read what you wrote. lol

[peterbeater]

i understand that you have gone through hell and back trying to work out the kinks in this taotao 50cc. i have this exact same scoot, but its a 2013. some of us are less than mechanically inclined, and i was wondering... besides changing fuel lines and vacuum lines, oil/gear oil change, and new plug, what are some easy "bolt-on"s that will improve this scooter:? from what ive seen so far, a carburetor with new jets.. what else can i do? ALL help is appreciated (by anyone). ty in advance

[90GTVert]

To be fair, a lot of stuff I've done as of late is consistency related more than anything. Other than when the variator totally failed, a lot of the CVT stuff headaches for me are related to consistency. Since I record 0-30MPH runs and MPG and MPH and so on for the purposes of comparison, I spend way more time than anyone should worrying about a couple hundred RPM here or there. The CVT would need some changes over time I suppose from wear and spring fade, but nothing that couldn't be much more easily handled for someone that just wants to ride.

IMO the best thing you can do to one of these is a big bore kit. That's not the most simple "bolt-on", but it's the biggest change you'll get. If you take your time, most are very capable of doing a BBK install. I've got instructions up step by step in the Tech Library. The toughest part of half the mods you do is the carb and CVT tuning IMO. Both should be done to even the stock scoot IMO and things like filter, exhaust, carb will require re-tuning. The carb is a good one, but at that rate why not throw on a big bore instead of the filter and exhaust first and get a big gain with your work? Ignition stuff, air filter, exhaust, clutch, and variator, are all small gains (some no gains) compared to a BBK.

My choices if the BBK is a little much for you ATM would be good unsealed carb, jet kit, sliders, 1000-1500RPM clutch springs, possibly a 1000RPM contra to at least have around in case the stocker starts losing it's stiffness or to help get in tune with the weights you have.

[peterbeater]

wow man, thanks alot. ill look into the BBK (sounds cool) if i do the kit, will it cause extra strain on the other components that arent engineered for 100cc? i only ask, because this is my daily ride, and i use it to go back and forth to college. i judt dont want to start changing things that may damage my ride. and, again, thanks in advance