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Post by 90GTVert on Jul 26, 2012 12:53:34 GMT -5
I get that it needs to make enough power to make the CVT work. It's just that from the way it feels at times, I believe it may be making more power. The problem is, it's hard to tell with a butt dyno when it's been weak for a while. Maybe it feels better cause I've taken so many crappy test rides? Life would be much easier with a dyno. lol
Before I try any other pipe, I'll remove the spacer. By my logic, if it's making enough power to go 40+ without the spacer, it should be making enough power to do the same with the spacer just by shifting farther. In past test, removing the spacer has not sped it up, because it did not have enough power to pull the gearing created by the pulleys getting closer together. Same thing with even the aftermarket variator. No matter how I spaced it, I was only making enough power to hit a certain speed... unless I spaced it too far and then speed dropped. Seems worth trying anyway. My goal is to get a more clear result of what the porting itself has done, good or bad, so I'm just trying to cover whatever I can think of with the stock pipe in place.
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Post by 90GTVert on Jul 26, 2012 14:16:59 GMT -5
I'm either ready to move on or ready to put one of the 90-100cc engines back in it. The wind kicked up now, and something about fighting a headwind at 30MPH with a 103cc sitting on a shelf just pisses me off. :laugh:
I tried no spacer and I tried the modified face. No real improvement. Went 42MPH without the spacer... but that was with the wind. I guess I'm ready to call it lack of power for now, unless it does the same thing with a pipe, then I'm lost again. lol
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Post by 90GTVert on Jul 26, 2012 15:34:08 GMT -5
I went back to the stock drive face w/spacer. Still 5g sliders/1000 contra as it has been for the majority of tests in P49. I changed to the Leo Vince GP, and went to an 85 main since it ran that before.  48MPH, sitting up, flat ground, but with a tail wind. It did that at just over 9,800RPM. It's dead at lower RPM now. Hard to say for sure because wind screws with my perception of what it's doing a bit, but as of now I'd say it doesn't hit it's best power till probably 8,500RPM+. With the stock pipe it would go at 8,000RPM and get similar speeds as when tuned for 7,500RPM, but it just wasn't quite there. Above 8,000RPM and it basically started to sound like something was going to explode. Now it thrives well beyond 8,000RPM. I was really trying to rule out the pipe being a total mismatch, because Project 90 used the exact same pipe, with even more duration, and had excellent results. I'd have to look back to be sure, but I know it was seeing max speeds achieved at 8,500+ with the same exact pipe. Temps were over 340 degrees, so it's possible I may need more jet. It's also 96 outside, so I dunno. Not sure if I can get better results with different weights or what yet. ...And I know... I know... you all told me so. lol I really wanted to be sure I couldn't tune strength into it before I moved on. Still, thank you for all the help and suggestions getting through the dead zones. It woulda took me a while to figure out that exhaust port issue, if ever. |
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Post by 90GTVert on Jul 26, 2012 19:03:18 GMT -5
Some guy broke down in front of my house with a flat on a scooter. I let him air up his tire and the valve stem blew out. First time I've actually seen a chinese valve stem fail like I hear they do. It looked good to go, he got ready to check the pressure and the metal stem shot out of the rubber seal. He was gonna ride it home on the flat, but I didn't wanna see him ruin a wheel over a valve stem so I took him and his scoot to his home in the truck and let him keep the gas money he offered. Honestly, I don't believe in it, but I'm hoping karma will be my 4 leaf clover. lol Last time I broke down some guy on a scooter taunted me and then turned around and rode off the other way.
I took a ride instead of doing much more tuning. It's too hot to be in the garage day and night. I might post a vid in a bit.
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Post by 90GTVert on Jul 26, 2012 19:32:21 GMT -5
Again, I have not spent the time I should tuning it. Just a vid from the ride. 53MPH max, tucked, tailwind. In the vid I am riding sitting up with a tailwind as well. It's slow getting there, but just seeing 50MPH feels good after thinking I failed miserably on the port job.
This is the modded drive face, 4g sliders, 1K contra. You can see the shift sure came back with the modded face.
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Post by tygertung on Jul 27, 2012 12:32:40 GMT -5
One thing I learnt as an Aircraft Engineer is that it is very important to oil the theads of hardware before you do them up. I noticed that you have been having bad luck with crank threads, maybe you need more oil?
53 mph is very fast for a 50, thats excellent performance. I can only get about 42-43 out of my factory 50 suzuki with very mild porting and more squish. Has a Top Racing pulley kit though.
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Post by 90GTVert on Jul 27, 2012 13:10:43 GMT -5
I never oil the threads in the CVT. The only time I ever oil threads is for setting to specific torque specs. I use an impact and a 38# torque stick to tighten the variator. If oiled, would it not be tightening the nut even more than without oil? Shouldn't that be worse? The right answer would be to use a torque wrench, lock the crank in place, oil the threads, and use a torque setting appropriate for oil. As great as that sounds, I doubt it's gonna happen.
I really believe the biggest contributing factor in crank threads failing on Project 49 and 90 is overuse. I don't believe any sane person would remove and install the variator 10 times a day. In the course of a week I probably take my variator off more than the average rider would in their entire ownership of a scooter.
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Post by 190mech on Jul 27, 2012 18:33:33 GMT -5
How long did it take you to get the Sunl(4T turd) to make 50mph??And how much did it cost to get it there?How long did it last after reaching 50mph??? With your present port durations,I'd say a pipe is a must on that little feller..Will be interested to see how it runs with the other pipes..  |
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Post by 90GTVert on Jul 27, 2012 18:47:17 GMT -5
I was thinking about that myself John. There's a reason the SunL got chopped up and sold for scrap. lol
For a pipe that I've read numerous unfavorable reviews on, I'm quite a fan of the Leo Vince GP right now. I'm very impressed with the little 2T. I really thought 50MPH on a 49cc wouldn't happen for me or at least would be a lot more difficult.
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Post by tygertung on Jul 27, 2012 20:57:40 GMT -5
No it is worse without oil as the threads gall up and then they will have a tendancy to strip. If you do up a stainless nut on a stainless bolt without oil they pretty much gall up and strip instantly.
I always oil any hardware I am doing up except into plastic, or if I am using locktite/ anti-seize etc.
I pretty much never use a torque wrench at home, just use engineers feel. You can feel when the bolt etc stops stretching and goes tight. I don't have an impact gun, so I don't use one.
I did notice on the mineralli engine that there isn't really any convenient way to stop the crank from turning. On the Morini you can just wedge a screwdriver in the starter ring gear as it is just splined onto the crank, but you don't have that option on the Minerelli. I just used some giant multigrips on my dads one. A bit rough I know, but what can you do?
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Post by palezu on Jul 28, 2012 8:53:30 GMT -5
The crank can be locked in place with locking pliers in the kickstart "crown" washer. I use that method when I don't mind listening the air compressor to get my impact wrench working ;D But great that you got it working! 50mph is pretty good. My record was 48mph with DIY tuned pipe, completely stock cylinder except the bottom skirt edges rounded as you have, head gasket removed and a Malossi Multivar variator. I was going to tune more, but then the police came and took my licence plates  45km/h (28mph) limit for mopeds sucks here in Finland  Just for giggles try to rev it without the drivebelt in place and see if it revs over 11 000. I'm surprised if it does. Because that is what restricts top speed on these. You said that the 90cc ones rev past 12 000 with the same ignition but, still I am surprised if this 50cc revs over 11 000 with the stock ignition. Here some Yamaha Aerox mopeds go almost 60mph with just a tuned pipe (usually Stage 6 pro replica) and better variator. The porting is almost identical with these and they do have even more "restricted" exhaust port (half moon shaped hole). Some extreme tuners here have tuned old aircooled Suzuki PV50 engines (50cc) to go over 62mph which is absolutely crazy. The engine design is like 30 years old and it has only 4 gears so I'd think that over 62mph should be possible with these scooters too ;D One PV50 record machine I know, had 21mm carb, DIY combustion chamber with 50% squish and gap was under 0,5mm I think, DIY tuned pipe, exhaust port timing was around 190 I think and it had ignition customized from a Derbi moped. And it went 64 mph. Well your mission here is probably not to tune this to go as fast as possible but here are some thoughts ;D |
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Post by 90GTVert on Jul 28, 2012 9:21:59 GMT -5
That sucks about your police. I'm sure it'll happen here someday, but I wouldn't know what to do if I couldn't mod without a constant hassle. That's prob the one reason it's sorta nice that people here think of scooters as a joke or just for people that can't afford a car. No need to make a bunch of laws for the 10 people in my area that ride. lol
I can't imagine an air cooled Chinese 49cc taking a 300lb man to 60+ and being a good street scoot, but perhaps I'm wrong. A week ago I didn't imagine getting to 50.
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Post by 90GTVert on Jul 28, 2012 15:58:42 GMT -5
My first victim :laugh: ...
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Post by 90GTVert on Jul 29, 2012 13:39:49 GMT -5
I'm gonna bash my head into a wall soon. The 49cc (lack of) torque is killing me. I've got it in tune... but I can't get it off the line. It could be seconds faster taking off if I could just get it to leave without bog. Stiff clutch springs make it rev nice and high... but it starts off in high gear. Not so stiff clutch springs make it take off in a good gear... but it doesn't have the power to pull. It's fine past the first 10MPH and runs way stronger than before. I'm not sure that a little engine combined with porting and a pipe to steal what torque it had under 7000RPM is a very good idea for a fat ass. I dunno though. It'll leave my garage fast. Give it 30 seconds of use to warm up and it's junk. I opened up the CVT even more and it didn't do anything. I've got pics, I'm just frustrated ATM. I'll get the pics up later.
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Post by 90GTVert on Jul 29, 2012 13:51:05 GMT -5
I should mention I'm using the Hoca variator. I could get it off the line with the stock variator much better... but I couldn't keep RPM steady. With the Hoca the RPM is way more steady and it gets up to speed very nice by keeping in the power band. The Hoca is far superior until the CVT warms up and then it's only far superior past 5-10MPH. I'm not getting any more speed out of it with the Hoca. That seems to be a power limit still. Just keeping in the power band much better.
Cruising speeds sitting up are low-mid 40s. Get a tail wind and it might sneak up to or near 50. Get a head wind and it'll be high 30s. In most conditions though, it stays between 42-45MPH.
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