need help with tuning

[motulken]

Hi,
  I'm building a scooter for my nephew. It's a 2004 super 9 lc deristricted. Just did rings and piston to freshen up the motor. It ran good with stock pipe and stock 8.5 gm rollers. Of course I want more so I added a Leo Vince tt pipe and lighter ( came with the pipe ) rollers 6 gm.  It pulls good at high rpms and climbs hills good but I have lost all bottom end. When you crack the throttle it revs to 4000 RPMS but will not pull ( move ) at all, after a few seconds of lag time it comes on and runs strong.I have played with lighter rollers but all that happened was I lost top end speed and the motor rev like crazy. At this point it cannot pull out of it's own way and is about dangerous in traffic. Any suggestions? Do I need to change torque or clutch springs?  I hate to just replace parts trying to figure it out. Any body have the same experience?

[thebatman]

Mine don't even move till i have 5g rpm... Which springs are you running

[motulken]

thanks for the reply. I believe they are still the stock spring both clutch and contra spring (big spring).
I have the follwing sets of rollers and have tries several combinations 6gm, 5gm, 3.5gm. I have the stock 8.5 but did not put them back as it seem the the heavyier I went, the worse the take off got. Even with the lighter springs take off never got much better, but the RPMs were reving to 12K and the top end went down from 40 to 30ish and it was screaming. With the stock pipe and rollers, it took off good and topped out at 45-50 (at least on the speedo ) and the RPM's stayed about 10-11K. My buddy and I though the stock pipe was stopped up, it felt like it weight 40 pound. That's why I change the exhaust to the leo Vince tt. The scooter has about 9000 miles on it  What do think I should do?

[motulken]

Thebatman, just noticed your from Asheville. Me to. Saw your post about clutch springs and contra spring on another forum  "Oh yeah, I had use 1500 and 2000 clutch springs on my zx when it was modded stock. the 1500 with a 1000 contra should be good...(then jet the carb. )"

Do you have any of the clutch springs laying around? I'm trying to get the scooter done ASAP.
Thanks

[thebatman]

  Your kidding me right??? Your in town..... Your THE 1ST i've seen on several forums that i'm on. I was the only "mtn man" around..
I'm not sure of the rpms made for the tt.(whether its a low rever or high rever)
I woulda thought the 7s would be close(when i got mine it had 6 g dps in it, i changed pipes to the rs2 and installed 7s. The fine tuning i havent mastered yet. I do have the building/porting,etc down pat tho.. .. Did you stagger any for even more weight combos?... You can use 3 and 3, just stagger them in the variator, good for tuning but dont keep it that way long
I do have some fly springs laying around i do believe. I have a used 1500 main spring.(mine had a "red", going to a "green" today i hope) I had several mains but it seems all mine went bad at one time.. . You can probably get a main spring local. I will be glad to try and help... maybe you can help me with fine tuning at the same time....

[motulken]

I did try staggering them in many confgiurations. Nothing seemed to help. I'm thinking it may be the clutch and or the springs being wore out. I owned this scooter a few years ago and sold it to a buddy. He put 5000 hard miles on it. When I got it back it had 90 lbs of compression and was hardly running. He used it alot and rode it two up alot. When we changed the rollers we did not take the clutch apart to inspect. I guess thats my next move. I'll check with some of the locals first to see what parts are here before ordering off ebay from Tiawan. I have an Aprillia SR50 that runs great. I bought a Leo vince pipe for that one too. I've got a buddy that works there and got a smoken deal, but I'm afraid to change anything cause it runs go good. I'll let you know what happens.

[thebatman]

There are a few good websites for malossi products that are in the states..(i use malossi springs, brand name, good quality).. Provoscooter.com is where i order lots of bits. and mopedhospital is a good one also but they dont sell malossi, they sell jasil...
Ha, i also have an aprillia sr50, '09 model. but i'm seriously considering selling mine. A buddy had actually listed it on C.L for me, w/o my knowledge but it's looking like it's gonna be a reality. It's a sweet ride, i love my kymcos but they don't have a thing on the ap

[motulken]

Hey batman,
  Well got the GY6 genric compete clutch  and hub bell here locally. The Stock one looked well worn and pretty thin, the bell hub was very blue and looked like it had been very hot. We swapped eveything and put it back with the 743X20X30 belt. Still no luck. It runs great and pulls hills good but will not take off at all. Tried the 5 GM weights still no luck. I'm going to order the right belt next. Getting ready to replace the front variator with a new GY6 kit. When I  replace the front variator with a generic  GY6 kit will I use the stock sized belt for the Kymco 748 X 18 X 28 or do I need to get the belt meant for the GY6?  If I need to use a different sized belt which one? 729 X 17.7 X 30? I was in a hurry to get this done. I wish I had used Kymco parts now but I was trying to save money. I'm giving this to my nephew and was trying to not spend to much or make it too unreliable. He is hard on stuff.
My SR is a 2004 ditech. I really like it.
 I sent a message to http://www.scrappydogscooters.com/Tech_Talk_with_Mo_.html. I'll let you know if he responds. Thanks for the help.

[thebatman]

Yeah, i think that belt is really to wide to get down in the pulley for a good take off...
Which "shop" did you get your parts?..(im way scared of the 2 on haywood rd,1 in malvern hills)

[motulken]

I'm worried now that I have switch to the chinese GY6 parts the Kymco sized belt won't work.I am concerned with the lengths. Stock is 748mm and most of the chinese with 12" wheels use a 729mm
( maybe the pulleys are a different size because the Motors are the same) Maybe i'm worried for nothing. Parts are on the way. I'll know next week. It looks like the weights controll the RPMs, the 5's let it rev to high IMO. If I send it to my nephew with it reving to 12 to 13K RPMs he will blow it up. The 6's let it rev to about 10.5K, wihich is still above red line but feels safer to me for him. With the 8.5 stock ones it only reved to about 8.5 or 9K which was at or below red line. It looks like 6 or 7's will be what I want. I have delt with both shops on Haywood. They are owned by brothers. Both have treated me well. It depends on who has the part I need. Of the two I think C & J's, has been most helpful on questions and helping with used parts if he has them. When I'm in a bind and need something ASAP I will go to C&J first. Charley the old guy is the one I deal with. I have never had them work on anything. I am usually trying to use my connections to get deals or order myself off ebay and I have a buddy who is a decent mechanic. Mary at City foreign on Merrimon is a great source too but she leaves the hard core scooter stuff to the others. I'll post up after the parts are on. If I can get it to take off I'll be happy, the top end is runnig great. I've gone to the one in Marvin Hills, they were useless.

[thebatman]

Are you going to use the gy6 rear pulley? I would just shange the clutch out
But the var and all should be the same either way. I have bought and used things for "the gy6" on my kymcos. I was blessed with parts after i was addicted but now i've screwed some parts up so i'm back to square 1. I'm going to install my new contra spring and 35 pj today tho and hope that helps out. This carb tuning stuff is killing me..
Yeah, mary is awesome. I go there any chance i get. She can order certain items for the cvt's tho but some are higher than the net of course which sux. I rely on this forum and others for the "hard core" apps...
Yep, that guy is way useless. That's probably why he's had to move 4 times since opening..
There were a cpl things that the old man at c-j's that just killed me. One time i stopped in and i was talking to a guy about shaving the head and setting the squish for more power. The old man told me i was full of sh**, i was lying that it couldnt be done, I had just gotten 4mph from it so I KNOW it works. That just rubbed me wrong, + he was talking about the bbk's being a
"plug and play" type thing. I KNOW that's wrong Unless you don't mind it blowing But yeah, he may have a quickly needed part that does help tho. That's another reason why i'm trying to teach myself so i can avoid the high cost and i KNOW what's being done.

[motulken]

I hear ya on the abitity of the shops. He should have know that you can mill the head down and increase compression the trick is to not let the piston hit the head. Carbs are pretty simple as long as nothing is broken. I have not been into mine on the super 9  but if there is a diphram you need to check it closely. even a pin hole will throw everything off and make it impossible to tune. The 35 PJ seems big. The pilot only controlls the idle and closed throttle once you open the throttle everything goes to the main. I've raced and tuned on carbs for years.
Normally the way to check if the pilot is the right size is to have the bike running at idle then turn the air screw in. If the motor dies when you get it turned in it's right. If the motor keeps running then the PJ is too big. In the end you want the motor to idle smooth at about 1.5 to 2 turns out. That gives you a little adjustability, in makes it richer less air. Out makes it leaner more air. When you turn it in do not turn too tight. Just barely snug it. Are there adjustments on the needle? Slots with a clip. You can change the position to richen or lean it before you change the Main jet sizedropping the clip makes it richer raising the clip makes it leaner Do you still have the stock breather and filter or do you have an after market pod?
  

[thebatman]

I thought turning the screw in leaned it out and out made it richer?..
And of course i thought "raising" the needle richened it, lowering the needle leaned it?
Yeah, i was looking at a s9 database and everybody listed seems to use the 20pj that comes on the arreche carb..(btw, i have a 19mm arreche). A "buddy" that lives on the coast uses the same carb. he's running a 25 now. I should be using a 15pj up here in these hills.....
Yeah, these carbs are really getting me, i have the porting, durations,etc down now i THINK, but the fine tuning sux.. Mine can change daily up here.. Surely you have experianced that as well...

I have a kymco cobra sitting here that one day i'd love to fix or sell also. It don't have enough compression. I think if i had the head done to set the squish(these have a HIGH squish set) i could raise the comp enough to get her cranked. My broke ass figured jus to use it for parts here lately. Kindof hard to have THIS hobby while broke. Yet another reason i should sell the ap, so i can buy kymco parts...
We will have to meet up sometime,mtn ppl here are VERY sparce. I tried a local forum but NOBODY EVER signs in or works it so i stopped pretty soon. I'd love to have a yard full of the s9s. I have another thats being a long term thing cause it needs several more parts. I finally did get to hang the engine yesterday tho...FINALLY.... I hope i can get my ZX back out of the grave one day soon, i miss my z. She's my baby..(have a build thread on her). Been riding the aprilia lately

[motulken]

What's up,  Any luck on your carb? I had to travel for work to Mass and PA. I was waiting on parts to come in for the Kymco. In the mean time I bought an Italjet Dragster from Charlie on Haywood road. It's bad to the bone. Got the right belt from Mary and a new vatiator for the super 9, I bought a chinese gy6 for $20 of ebay. Everything is back together now. Used the 6gm weights that came with the Leo Vince pipe for a starting point. Runs much better. It will pull off and run now. Top end is great acceleration is great. Only small thing I noticed was when you crack the throttle it moves and takes off but it seems like it take a few seconds, too long for me,  for it to switch to the higher gear and really take off. Any ideas? From my research it seems the GY6 139 style clutch that I used comes with a 1000 rpm spring. Everything is stock on the super but the new pipe. When I used the lighter rollers it seemed like it let the engines RPM's rev higher 12K vs 9.5K. In the end I will give this scooter to me nephew. He is a dystroyer and if it revs too high he will blow it up. I'm thinking stronger clutch springs but my mechanic says give it time and ride it. I only did a quick test ride up and down the street. 

On your scoot, there a alot of parts out there on ebay that are cheap. If theres no compression, like my Kymco ( 90 PSI ) when I bought it from my buddy, you can just do the piston and rings. Check out this link, http://www.scrappydogscooters.com/Replacement_Parts.html  Lots of info on coversion parts. I also have a sourse for OEM Kymco parts so you do not have to go to the pirate in Hendersonville.  But Kymco is proud of there stuff pricewise.
 
 

[thebatman]

Oh sh**, Is the new scoot "copper"?... I seen that one, It did belong to the "pretty boy" that worked there. I don't think he is there anymore tho. I thought that was his son in law..IDK.. NICE FIND!!!!!! I wish i'd had known you were looking for a scoot, i need to sell my 09 aprilia...

Yeah, the 1000's may be a little light with a pipe, carb work.. Yeah, if it's revving THAT high, id try 6.5-7g rollers.(i'm not liking the malossi green spring i installed, my sh** hits 3rd "gear" to quickly. i shoulda got the violet spring  (mine had 6g dp's when i got it and that was witha different kit,HARd springs)

Your hesitation COULD be the same thing i am experiancing..When i "rap" the throttle, it bogs?, want to die out type something but if i "roll" the throttle i'm ok. I was told that's in the needle. I did order a different needle but something was way wrong so i put it back. I cant seem to get the tuning side of this down pat..It was suggested that i use the s1 needle witha 80mj.. NOW THAT, would seem a recipe for "meltdown", IDK. Hadnt tried it yet

I think my tester is garbage, my s9 is only reading 90- ISH lbs of comp, but i ride her.... The cobra has 90lbs with the same tester and all it does is soak the plug.. Oh yes, kymco is very proud of there stuff, yeah i try to go to stadium for my oem parts. Seems kymco has dropped the ball as of late. Seems everything is taking forever to ship out