The $100 Buddy 125 Project

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buzzvert
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The $100 Buddy 125 Project

Post by buzzvert »

As my wife has a 2017 Buddy 125 she won't let me get within 100 feet of if I have a screwdriver in my hand and I have a Vespa GTS 250ie, I wanted to find a cheap Buddy to gain some knowledge from and have some wrenching fun with.

Lo and behold, from the depths of scrapland and salvage police auctions, one C-note later I came into the possession of a 2007 Buddy 125 with clear signs of a checkered past. 9000 miles on the clock and abuse evident on the body panels, this Buddy was at a crossroads. Scrap it, or save it? I chose the latter.

Did the standard unknown-scooter-mambo, which is draining the fuel system, removing and cleaning the carburetor and jets, changing the oil and gear oil, and airing up the tires. So far so good. Starter did the thing it does, but obviously it wasn't going to fire off.

Pictured is the $100 buddy, complete with cafe-racer style wire-tied headlamp assembly that I CHALLENGE ANYONE TO MAKE FUN OF.

Opening up the pet carrier revealed the stock CDI and coil and sure enough replacements were freshly installed. Ah. Electronic issues. Cool. Let's check spark! Well, we have spark! And then we don't. And then we do! And then... yeah, you get the idea- the subsystem that tells the coil/CDI "hey, idiot, chamber full of gas, light this sucker up!" was intermittent. That's the stator and the teeny little hall-effect sensor giving me a hard time- likely the sensor. Boom, replaced that, we're running! The previous shadetree ALMOST got there. And then I'd put $5 on him getting frustrated and throwing this in a nearby dumpster. Or landfill. Or ditch. Easy! Yeah, no. Not so fast.

Getting the fuel/air mix close to right based upon what lit I could find, making sure I had no vac/air leaks, etc. resulted in a buddy that is quick to start, idle like a champ and accelerate wonderfully all the way... to... 40mph? No. That can't be right. That's Buddy 50 territory and my wife's 125 can do 65 all day long even with my portly ass on it.

So that's where I'm at on my $100 special. My question to the forum, after that lengthy diatribe is: would valve adjustments have that large an effect on top end/power on this drivetrain? What else could I be missing? Some more clues include random backfires upon deceleration. This seems to happen all around the fuel/air mix settings, I've tried leaning it out and enriching.

I'm all ears. And at least 5% grease/dirt from unknown origins.

Oh! Before anyone says anything, yes, the trans cover is off as I just upgraded the variator in my wife's 125 and had a nice new stock one laying around, so I threw it on to replace the never-serviced variator and used-to-be-rollers-but-now-are-sliders. Performance did not change significantly unless it's the rear clutch, it's not a tranny issue.
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scootERIK
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Post by scootERIK »

Might be the diaphragm in the carb. Either it isn't fully seated or it might have a hole in it.
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Post by buzzvert »

scootERIK wrote:Might be the diaphragm in the carb. Either it isn't fully seated or it might have a hole in it.
Yeah- I wondered about that. it looks kinda wrinkly and terrible. Intact, it seems, but also I'm a little confused as to what makes that needle go up and down with the diaphragm as the only air/gas lines going to the carb are the drain line from the bottom and the gas line. I see the two vac lines, one from the manifold connected to the air intake, and the other operating the vac draw for fuel... but maybe my brain is missing something.
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Post by buzzvert »

Pulling the needle, reseating results in a whole new world of initial bog on throttle and other fun! Yeah, this has to be in the carb.

If the dang throttle assembly wasn't a little different I'd just throw in a GY6 carb with the same in/out spec laying around. But yeah the CVK model PGO is using is... just a little different.

And pricing a new Buddy carb is... no. Just no.
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Post by buzzvert »

Before I get myself in trouble- a generic GY6 carburetor is not functionally different. The auto enricher, etc. all hook up nicely. What IS different is the distance from the throttle connection bracket to the throttle cable attachment. On a GY6 carb it's about an inch longer. That means you'd have to modify your throttle cable to suit. Not a big deal for many, but something I'd rather not do in testing mode.

(Update: some dumbass who I see every time I walk into the bathroom reassembled the needle assembly wrong with the plastic piece before the needle. At least I'm back to 40mph.)
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Post by babblefish »

Killer price on your Buddy. Good score!
The CV diaphragm is operated by a vacuum port internal to the carb. When making sure it's seated and sealed, put some rubber safe lubricant on the sealing surfaces. This will greatly help it make a good seal. If this and a thorough clean (an ultrasonic cleaner helps a lot) doesn't fix it then it may be time for a new carb. As you've probably already found out, a new OEM carb isn't exactly wallet friendly. But, eBay can be your friend (sometimes). This carb is a direct bolt-on replacement and the jetting should be pretty much spot on. Doesn't hurt that the price is significantly cheaper than OEM. I've said this many times on this forum, be wary of the cheaper carbs ($18-60) on eBay. While these will allow the engine to run, they are not made very well and lack an accelerator pump like the stock carb has.

https://www.ebay.com/itm/OKO-24mm-CVK-C ... xy14VRWj41
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buzzvert
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Post by buzzvert »

babblefish wrote:Killer price on your Buddy. Good score!
The CV diaphragm is operated by a vacuum port internal to the carb. When making sure it's seated and sealed, put some rubber safe lubricant on the sealing surfaces. This will greatly help it make a good seal. If this and a thorough clean (an ultrasonic cleaner helps a lot) doesn't fix it then it may be time for a new carb. As you've probably already found out, a new OEM carb isn't exactly wallet friendly. But, eBay can be your friend (sometimes). This carb is a direct bolt-on replacement and the jetting should be pretty much spot on. Doesn't hurt that the price is significantly cheaper than OEM. I've said this many times on this forum, be wary of the cheaper carbs ($18-60) on eBay. While these will allow the engine to run, they are not made very well and lack an accelerator pump like the stock carb has.

https://www.ebay.com/itm/OKO-24mm-CVK-C ... xy14VRWj41
Thank you a ton for the research. I've been doing some forensics on this carb... I'm now 95% sure it's a Chinese-sourced CVK26 based upon the markings, accel pump and what little part information is on the componentry. If it is, it's this: https://www.ebay.com/itm/CVK26-26mm-Car ... SwjexboAMR

At the price point I'm going to order one just to satisfy curiosity. Even if the diaphragm and auto bystarter is good, I'm ahead.
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Post by babblefish »

I've not seen that carb but it should be a direct bolt-in like the one I posted. Certainly can't argue the price, though I have to question whether or not it's an inferior copy of the Taiwan made carbs that look the same. One other thing that stands out to me is the picture of the venturi opening. They say it's 26mm but it sure looks a lot smaller compared to the picture of the carb I posted. Looks almost like a 19mm carb meant for a 50cc engine. Of course, it could be just a generic picture they used. Let us know how it works out for you. The only problem I see is that it might be too much carb (26mm) for a stock 125cc engine. The stock carb on a 125 and 150 is 24mm.
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Post by buzzvert »

That was the interesting thing on this CVK carb- "MADE IN CHINA" stamped big as life on the body of it. When it gets in I'll take a micrometer to the specs. the OD (34mm) is the same as the stock CVK carb but the internal being 26mm is reason for concern. At least it should fit on the stock intake. I'm at altitude, so jetting is weird, but I'll figure it out.

In the meantime while that's on a slow boat, I've got a million other things on this Frankenbuddy to work out, including valve adjustment, random bulb issues, a seat cover, and as many local brewery stickers as I can find to cover the cracks and road rash.
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Post by PNWbuddy »

And I thought mine at $300 was a decent price. I bought it for a project like it sounds you did. It was not running but only ended up needing a <$10 voltage regulator/rectifier to make it go. I stripped it down, cleaned it up, changed fork oil, rollers and belt (the original belt looked new at 11,000 miles), did a 161 Prima big bore. Cosmetics included making a new seat cover out of some scrap fabric using the original as a pattern, painted the weathered plastics with Plasti Dip. Made a front rack, added running lights where the dummy turn signal bulbs are, added some strip LED tail lights with a brake light flasher. New Shinko tires 110/80 on the front, 130/70 on the rear. The headlight trim ring on mine doesn't seat properly for some reason which might also be the reason yours was wired on. I had fun with the project and now only need to find some excuse to ride it.
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Post by PNWbuddy »

PS I found this thread when looking for something else, same 40mph as yours and it was the carb diaphragm.

http://www.modernbuddy.com/forum/topic31525.html
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Post by buzzvert »

You guys and your good advice.

So what I thought was a "good" seal on the diaphragm was... not. Out of an abundance of redneck caution, I ran a tiny thin bead of "tacky glue" into the groove where the diaphragm ring should seat. I wanted to use a water-based glue as this could be a) removed and b) wouldn't eat the rubber in theory.

58 mph attained, GPS verified.

Thank you all for not giving up on the diaphragm diagnosis and pointing me in the right directions.

EDIT: I did attempt the rubber-safe lubricant first- it wasn't sufficient to keep the shrunk CV diaphragm into the seat groove. I'm not a real big fan of using glue on carburetors, but means to an end, and all that.
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FLOOR MAT!

Post by buzzvert »

My wife's 125 has a nice floor mat but I'm always feeling like it's a little too insecure. I just made this from a $9 floormat from Walmart and using my wife's mat as a template. I secured it with short screws after predrilling the plastic in safe locations. Yeah it's three more screws for battery access but I don't think it's going anywhere.
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Post by buzzvert »

Approaching final product. Low profile mirrors and cheeky decals on order. I went with a complete rear tail delete with no grab bar or carrier, and I like the look. So far I'm into it for:

Initial cost of scooter: $100
Partial front fork assembly replacement: $15
Front hydraulic brake fluid replaced, bled, pads serviced
Voltage regulator replaced (preventive maintenance) $10
LED Headlamp: $19
Entire ignition module, w/keys: $99
DIY floor mat: $9
Carburetor removed, cleaned, disassembled/reassembled, reinstalled
Seat cover: $70
Stator assembly replaced: $30
Oil changed: $3
Final drive (gear) oil changed: $1
"new" stock variator/rollers installed ($0 on hand, leftover from upgrade): $0
LOTS of body panel/trim/touchup work


TOTAL: $356
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Post by babblefish »

She's looking great. Outstanding bargain you have there. I also got a great deal on my Buddy but not as good as yours. On the plus side, other than oils, I didn't have to replace anything. If you're interested, here's my on-going post on my adventures: http://www.modernbuddy.com/forum/topic30354.html
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Post by PNWbuddy »

buzzvert wrote:
Thank you a ton for the research. I've been doing some forensics on this carb... I'm now 95% sure it's a Chinese-sourced CVK26 based upon the markings, accel pump and what little part information is on the componentry. If it is, it's this: https://www.ebay.com/itm/CVK26-26mm-Car ... SwjexboAMR

At the price point I'm going to order one just to satisfy curiosity. Even if the diaphragm and auto bystarter is good, I'm ahead.
Did you end up getting this carb, if so does it fit and run well?

Addendum:
I ordered the same carb on Amazon for $30, one day free shipping so I couldn't pass it up because I want to give it a try. I've bought a few Chinese clone carbs for other motorcycles, they have all worked perfectly so I'm hopeful fo this one.
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Post by buzzvert »

PNWbuddy wrote:
buzzvert wrote:

Did you end up getting this carb, if so does it fit and run well?
I was able to finally get the shrunken vac diaphragm seated and I'm using the stock carburetor successfully. The cheapo carb is still on a slow-boat with no ETA, but when it gets here I'll pull out the stock and do some test runs and side-by-side comparisons/photos. I'm particularly interested in the in/out dimensions and the fuel flow/jetting differences. Stay tuned!
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Post by PNWbuddy »

I got the Amazon version of the carb. It is a Keihin exactly like the stock carb including markings on the body of the carb and on the jets. The only differences I could find that I could find was that the fuel line connection is longer and curved instead of the straight shorter on the stock carb. It came with a 38 pilot like the stock but a 118 main jet which was way too rich for my 161 even with the fuel screw turned full in. I put a 96 main in (stock 92) and it ran great and topped out at 51 which is faster than what I got with the stock carb although I had the stock carb jetted a bit richer with a 98 main. So for $30 instead of $300+ you can get a new carb for a Buddy 125/150 and will just need to get smaller main jets. I'm interested to see what you got on Ebay but I'm guessing it was the same carb.
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Post by babblefish »

That's interesting that you only got to 51 on a 161 Buddy because my stock Buddy 150 will easily do GPS 60 with a little bit more throttle to go. I'm wondering if the final gear ratio of a 150 is different from a 125 and if so you can change the gears in yours to get a little more top end.
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Post by PNWbuddy »

yeah, I don't know what the deal is with mine. It is running like a scalded cat but won't do more than 51-52 on the flats and it won't go faster even downhill. Besides the new carb I put an unrestricted CDI in, no change with that. I bought some 13g Dr Pulley sliders and will see what if anything they can add. 51mph feels freaking fast on the buddy, to me at least, but if that is all I can get it to do it will have to go. I'm not planning to do anything like changing the final drive gears.
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Post by babblefish »

You can also try getting a so called "overdrive" variator. It's basically a variator with drive plates that are a little larger in diameter to allow the belt to ride higher which essentially changes the drive ratio to give you a little more rear wheel speed.

You're right about the Buddy getting squirrely at higher speeds what with it's light weight and smallish wheels but a lot of that has to do with the stock suspension, in other words, the stock front forks and rear shock. They're both too soft for high speed work or even fast cornering. If you can swing the expense, it's definitely worth getting NCY front forks and a performance rear shock such as NCY or YSS. It did wonders on my Buddy. I don't think twice about taking sweeping curves at 60 MPH now because other than the wind she's perfectly stable. Just regular riding around town is greatly improved too, if you don't mind a firmer (but controlled) ride.
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Post by PNWbuddy »

I'm not looking for a higher top speed than what 125 owners have posted so other than some Dr Pulley sliders I'm not going to change anything in the drive train. Reliable sounding top speed reports are in the mid 50s to very low 60s for the 125 so the 161 should be able to do at least the same.

The suspension on my Buddy is as firm as I think I would like. I changed the fork oil which was low, not the same amount in each fork and like typical old fork oil smelled nasty. I used 5W30 oil, stock is 10w20 so that might have firmed the forks up.
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Post by k1dude »

If 51 feels really fast to you, I wonder if something is wrong with your speedometer or cable. Have you GPS verified your 51?
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Post by buzzvert »

Updated the floor mat by trimming a $6 Wal-Mart doormat to size. I REALLY like the grippiness and thickness.
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Post by tenders »

Love this thread.

Buzzvert, tell us about the looped fastener under the headlight with the Incredibles boy swinging from it in your signature photo. Is that an entire metric threaded fastener, or is it something clipped on? Is it intended to let you unscrew it without a tool, or is it just decorative? (It bears some resemblance to a horse harness clip, which is also amusing.)
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Post by buzzvert »

tenders wrote:Love this thread.

Buzzvert, tell us about the looped fastener under the headlight with the Incredibles boy swinging from it in your signature photo. Is that an entire metric threaded fastener, or is it something clipped on? Is it intended to let you unscrew it without a tool, or is it just decorative? (It bears some resemblance to a horse harness clip, which is also amusing.)
It is indeed a metric threaded single-piece fastener. I have no idea where it came from and what its initial use was, and it was in my big bin of random hardware (edit: if I had to classify it, it most resembles a hoist ring but there's no internal tightening bolt- it's integral to the entire assembly). I initially did use it as you guessed- to be able to remove the front fairing assembly w/o tools while I was building up the bike as the ignition system was in need of replacement.

Also I'm not sure how this happened but this bike is starting to develop a theme (see attached).

(EDIT: Yes, I am aware this plate is expired. Ha. Until I can get this titled in Colorado (in progress), it's going to have to pass itself off as a 50. As far as I can tell it was never registered, even though it lived its whole life in Colorado. The scooter laws here are seldomly enforced anywhere outside of downtown Denver, Fort Collins or Boulder.)
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