Hi! I'm a fresh "new to me" owner of a Kymco Super 8 and I need your help!
So I purchased this Kymco about 2 weeks ago and have been pouring over manuals and these forums trying ti find a solution. I did what most scooter owners do and tried to get more power/top speed. List of things I've replaced and why:
I ordered a variator kit to derestrict the boss, the sleeve was already derestricted but the belt was frayed and the rollers were horrible...major flat spots and one was even cracked in half. These seemed to help however, being a novice at mechanical repair(I'm more of an IT guy), I'm not sure if I put something on wrong(drive plate?) but it still worked afterwards but didn't really notice much of an improvement.
Replaced the spark plug. It was pretty bad looking.
I cut the lower purple/red wire on the cdi as per somewhere on this forum, noticed it did get better accel and was getting between 28-30 on a straightaway but still felt a lil off.
Next I poured a whole 16oz can of seafoam into the gas. why? because on some forum or search I had read to 50/50 the mix if carburetor was possibly clogged. as soon as I did that once it started working through the system was when things went south.
I presumed I had knocked some debris loose with the seafoam and it has gummed up in one of the jets within the carb. I went ahead and instead of trying to disassemble, ordered a replacement carb as this one looked like the original(no slot on pilot screw). Received replacement carburetor and installed with new intake manifold and fuel filter. Did no adjustment to pilot screw and turned throttle screw all the way in(will detail more in a moment). took solid 30 seconds of revving to get to start, could see fuel going into replacement fuel filter as it was clear.
Now when I try and test ride it up and down a quiet road, it has multiple intermittent issues,l that present when both cold and warm. On a cold start it will start right away usually but sputters and will cut off majority of the time. pulling the tank cap and restarting seems to work but I don't know how I would be getting vapor lock? Either way when idling if I even turn the throttle in the slightest it will cut off repeatedly to where after numerous attempts to restart its like the battery drains and I need to throw it on a charger for a little while. when it does start to warm up it seems to do better with the idle.
today Was the first day I played with the pilot screw. I turned it all the way in and backed it out about 2 to 3 full turns. tried to open the idle throttle screw some and it would cut off unless closed. I can probably back it off 2 to 3 turns max.on the idle screw before it will not even run. when it does run accel at stop seems "ok" but will act like it isn't getting power and bogs down repeatedly and intermittently, I have to go down a dirt road to get to the main neighborhood street and I swear idk if I'm crazy but it's like hitting some bumps, knocks something lose enough to allow it to start running normal even if briefly. I'll get to the main street and accel out and as soon as I get to 8-11mph it just bogs down no power. I have to repeatedly turn the throttle 1/4 turn release and repeat to get it past 11mph and once it gets to 15-18 will start going up but will only max out 23-25 and isn't consistent. once I get.to the deadening and turn around there's a portion of the street that's slightly uphill, I always lose significant speed going uphill anywhere from 5 to 10mph, when I turn around and come back down that incline I can hit 28-30 and it'll drop down to 25/27 once I hit the straight away.
I've got a battery coming, another carburetor, a plug wire, and fuel pump/valve(the one in/under the tank) coming in case the diagram in that is damaged.
I feel like this is either something really silly that can only be attested to my novice scooter repair knowledge or something serious that maybe doing the seafoam wasn't such a great idea lol. please help, I'm at a loss right now.
Update:
So after receiving the new carb today I decided to just swap it out totally opening the pilot from seated to about 3-3.5 turns out. toyed eith the idle til the tachometer was showing pretty steady 1900 or as close to variable(within 100 or so) and took her for a spin. It started up much easier this time although it take a lil bit for the carb to fill. but I noticed at idle it was very response on the throttle. no bogging down and sounded much better than it did before I ever even started messing with it. I did notice where this tab depresses down when pulling the throttle was all jacked up on the one I had just removed. comparing it to the replacement I think I found the main issue, the tab wasn't depressing all the way and was barely even making contact, and slightly crooked. opening full throttle barely even pushed it down 1/4 of the way and seemed like it was sticking sometimes, co.pared to how low it was going when I would press it down with my finger and how fluid the replacement one looked and was depressing normal.
the only thing now is it wants to cut off when coming to a stop or turning around in a cul-de-sac, and having to pull throttle when starting. so maybe too lean? Will adjust the pilot screw half a turn in when it stops raining and see how it does then.
on the test drive I tried many diff things. coasting to a crawl, to a stop, seeing it it would cut off everytime(a couple times it didnt). turning it off, starting it back up, it seemed pretty consistent that it may need a lil more gas to stay idle, other than that, it performed and responded great, getting up to 28 on straightaway, zero bogging down occurred. accel to 20 was acceptable and felt more zippy than it had been, could stand to be a tad more zippy but hey it's a 50cc. going up a slight incline about 15-20° it stayed pretty.steady and maybe only lost 1-3mph at the steepest part, but I'm also pushing 240lb. downhill I was already at 25 before hitting the incline and easily got up to 33 at the bottom and stabilizing on a straightaway to about 26/28. I really wish I could hit 35mph at least but based on everything I've read, my next step would likely have to be a big bore kit if I wanted to achieve anymore speed.
