Hey, good eyes! Yeah, they are stock. The back one is worn from the previous owner riding it with low pressure. I'm kinda sold on Michelin Power Pure. 130/70-12 rear and 120/70-12 front. Going up a size on each, hopefully the speedo will read a lil more accurate. The stock Kymco tires last forever but they do have hardly any grip, so the Michelins will be nice.
Lol guess good eyes and a PC screen does wonders... anyways I didn't know you could squeeze a 130 in the rear, I would've bought a 130 for the zx if I knew xD
2008 E-ton Sport (72cc) Sold 2004 Kymco ZX50 Super Fever II(49cc): Arrow Limited, Stock Cylinder 2004 Kymco Super 9s(49cc): Leovince ZX Chrome (soon), Stock Cylinder 2004 Vento Triton R4(72cc) Sold 2000 Aprilia SR50 Leovince Chrome, Top Performance 72cc.(Rehab 72cc) 1999 Aprilia RS50 (All stock 49cc) 2003 Aprilia SR50 Ditech (part out only)
So sometimes I get too excited and forget to take pictures... but my 81.3cc engine is built and running strong!
I absolutely love the carbide bits I got, they made quick work of the ports.
Here's the stock on the left, my first rough draft on right:
Finished here, looks like the right is larger but it's a weird angle...
Boost port cut, photo was before I port matched the transfers and cleaned up the corners.
I popped in the oil plug, gave it a washer to hold it in place. Not the prettiest, but effective. Also shown is the SSP-G 50mm cast iron kit, chinese "big valve" fiberglass reed intake, 24mm PWK.
I had to open up this bolt hole. Was 2.5mm off.
Then the outside of the transfer touched the intake manifold, so I made quick use of the bench grinder and rounded the edge of the intake. Barely a gap between the two:
Boss man brought the engine to my house after work, I didn't have my trailer to haul it home. While waiting I was able to get the throttle cables swapped out and transmission pulled off of Scootie to use on this engine. Malossi variator, Bando 729 belt, straight groove clutch and all 2k springs.
Easiest engine install ever! Popped everything on, got the wires all connected, everything done fairly quickly. Fired right up! You know, after I kicked it over 5 times then saw the spark plug cap was off, haha...
Warmed it up and went around the block, 6g rollers was too light. Just revved out and really had no torque. Swapped to 7g rollers and it feels much better. Just those 2 little test drives and I parked it for the night. I didn't get any top speed run, was taking it easy rolling on and off the throttle just cruising around. Riding it to work, and probably gonna try some 8g weights... I feel like this pipe is a 7500 rpm pipe.
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
GPS verified 59mph... it just wouldn't jump to 60 😤 The RPMs haven't started to raise yet, either; the stock gearing must be super tall. I forgot to do the wheel vs clutch bell count just now as I tweaked some more things in the CVT.
The 59mph setup was: 9.5g Dr Pulley sliders in a Malossi variator using a Naraku back plate and 37mm boss. Bando 729x18x30 belt. Kymco Agility 50 clutch pads with 2k springs, stock QMB pulley with SSP-G performance driver using the straight groove and 2k torque spring.
I've never had to use such heavy weights before on any "50cc" build... but there's just no torque with anything lighter than 8g (dang pipe). With 9.5g takeoff pulling RPMs are 7600, then when it his 8000 around 40mph it starts to get on the pipe and really pull.
The variator hasn't shown full belt travel, yet. But I kinda went the opposite way, maybe:
Installed Bando PGO 738x18x30 (Genuine Roughhouse belt) and cleaned everything else up. The previous setup had a lag at low speeds, and the belt was pretty deep in the clutch pulleys at idle. With this variator being "overrange" and the longer belt, I am hoping for that snappier low speed and possibly similar or better top speed results. I'll find out later today!
Keep in mind, these speeds are me tucking fully like I'm racing the Polini Cup and I'm on the back straight... Sitting up I'm between 50 and 55 depending on wind, traffic drafting, etc.
The engine still only has 60 miles on it hehe I'm not even pushing hard yet...
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
That’s funny because when I was reading thru all I could thing was “damn those weights are heavy”.
But what works, works!
My guess is the super steep ramps in the Malossi variator. Needs more RPMs to get the weights to climb AND get thrown outwards at the same time. I might play around with a different variator/weights to see if I can get the take off better... it's really a top end tuned ride right now.
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
The 738 belt definitely helped the takeoff. No more low rpms til I get up to speed, this thing takes off and maintains RPMs pretty consistently now. I like the way if feels now, don't know if I lost any top end yet since it's still getting to 55 easy and I'm not pushing for that top speed all out run yet... another 100 miles of average riding then I can really let the beast out!
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
The 738 belt definitely helped the takeoff. No more low rpms til I get up to speed, this thing takes off and maintains RPMs pretty consistently now. I like the way if feels now, don't know if I lost any top end yet since it's still getting to 55 easy and I'm not pushing for that top speed all out run yet... another 100 miles of average riding then I can really let the beast out!
You really tempt me to tune my zx50 I kinda want an Polini Corsa matched with a arrow pipe, later do intake and carb... Hmm anyways, sounds like your ZX is running like a champ
2008 E-ton Sport (72cc) Sold 2004 Kymco ZX50 Super Fever II(49cc): Arrow Limited, Stock Cylinder 2004 Kymco Super 9s(49cc): Leovince ZX Chrome (soon), Stock Cylinder 2004 Vento Triton R4(72cc) Sold 2000 Aprilia SR50 Leovince Chrome, Top Performance 72cc.(Rehab 72cc) 1999 Aprilia RS50 (All stock 49cc) 2003 Aprilia SR50 Ditech (part out only)
Still running strong! Took the group over to Tampa and back, about a 90 mile loop. Most guys were on built 139QMB machines, had a good mix of rides though:
Even wide open across Gandy, where I had my only seizure on my 177 Polini kitted Stella, this one did fine at 55mph tucked. Knock on wood, this engine hasn't seized yet!
I finally figured out this one little bug I had, I think. Was having a "running out of fuel" situation happening at random, but got worse and started happening when I'd hit a bump. Fuel system was in check, no problems. Finally swapped out the CDI for a Minarelli stock CDI and it fired up and idled better, and hasn't had any bog down or hiccups yet!
After the Tampa ride I did a CVT inspection and found my rollers already flat spotted. I had installed them 2 days before the ride. Waaaaay too much heat so I did something...
Also been tinkering with belt sizes. Since I had no idea of the true size of the stock Bando belt, I've been experimenting with 729 and 738, both x18x30 sizes. The longer they go, the slower the top speed. I really think the stock length is 723. I seem to get the best speeds with that belt but the takeoff is just a little weaker. Gonna run the stock belt and dial in the weights to get the best outta everything.
Thinking I need to pull the top end down and cut the piston up a bit... like help the boost port out. I left the piston completely unmolested during the build and the more I think about it the more it seems it's choking out the boost port I cut into the case. Just gotta decide on how I wanna modify the piston; thinking one big hole matching the width of the port, and maybe slightly taller than wide. Just an idea, seems to not be as strong as I expected (but I am absolutely happy with the build don't get me wrong).
Oh, finally did the rear fender delete to clean it up a bit. Haven't snapped any pictures yet with the current setup but I'll go get some shots soon. Not completely happy with the looks so I'm gonna button it up then I'll show him off haha
One last ramble... this poor charging system. I converted the lighting system to DC for brighter, more steady lights. Didn't think about the double rear bulb setup... 21/5 x2 when grabbing the brakes is 52w being used in just the rear end, then another 35w up front for the headlight and this stator is prolly 70w max output. Yeah, my battery isn't charging anymore. Time to go full LED bulb!
Happy Friday everyone 🛵💨🤙
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
Well... Ziggy hit 62mph last night! Still haven't got into the gearbox yet. Sure does look like an Agility gearbox. At least I know the Agility wheel fit right on, same as 139QMB. Clutch is the same as well so hmmm do I see 70mph in the future??
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
The Chinesium reeds broke, but they did last longer than I thought they would! The fiberglass material looked to be cut with a cookie cutter... frayed edges and just low quality all around.
I was on my way home, about 2 miles away and at 3/4 throttle pulling up to speed he just lost power. Roll off throttle and it didn't die, just couldn't take more than 1/4 throttle or it would fall on it's face. I held the throttle barely open, maintaining 30mph and had to run a few stop signs to keep going... I knew if I stopped I would be walking.
Made it home and popped off the carb and intake spigot and sure enough, one of the six reed petals was missing. The metal spring on the backside somehow managed to go UP the reed assembly and land on the carb side of the block, not entering the engine (woohoo!).
And crap, looks like my phone didn't save the photos of the broken reed.
After further inspection, I found cracks in the plastic body of the reed block. 3 cracks total, one of them working from the mounting bolt hole all the way along the side. Air leak. The rubber gaskets that came with the kit just disintegrated.
I popped my RD350 Boyesen reeds on a Minarelli block a while back; so I decided to mod it into this engine. I mocked up the bolt holes and only had to make little cutouts on the side of the Minarelli block to get it to fit. Fresh home made gasket material, and viola! a new higher-flowing reed assembly!
Upon first ride, holy crap is this MUCH MUCH better than the Chinese block! Much snappier throttle response and harder pulls. Now to get the YMS V8 exhaust... seems like that's the pipe that'll really wake the beast.
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
Post by chadbullet on Jun 10, 2021 11:49:14 GMT -5
I'm really glad to see that reed mod work! It seems like there are so few options for these engines compared to minarelli. I'll have to take a look to see if my malossi minarelli reeds will work as well.
Here's a short video of me just getting up to speed on US19. Ended up getting 64mph again going down the other side of the hill at the end of the video. I really have good feelings of getting this thing up to 70mph hehe VOLUME WARNING (shitty microphone sorry)
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i
So hey, today I got to 72mph! Holy crap I couldn't believe it... Had some asshat nearly miss me while travelling up US19 so I got a lil road rage and tried catching him...
Haha yeah, on an 82cc scooter. I'm dumb sometimes. But, I was able to catch a top speed of 72! The only thing I've changed since the last post is the crank bearings and I port matched everything a little better. Still using the extremely restricted NextR pipe. I was full tuck, with tailwind and going down hill... But sustained 65 on the flats.
Found some gears today I think will fit, and I might be pulling the trigger on a better pipe soon hehe
Scootie the 88cc 139QMB has been rebuilt too many times ...and... Sonja the 2005 Genuine Stella 150cc ported 2t freebie ...and... Ziggy the Kymco ZX50 82cc street race two stroke ...and... Equinsu Ocha the Kymco People GT 300i