06 Buddy 125 - Help, Out of Ideas

OKMatt · Post by **OKMatt** » Tue Aug 15, 2017 11:49 pm

Hi All

Just bought a 2006 Buddy 125 on the cheap that had been sitting for a year. After much work, I can't get the scooter to idle and it surges between 0 and 20mph. After that it lines out. Let off the throttle at a stop and it dies. Below is a list of things I've done so far:

New battery
Drained gas tank
Changed oil and oil filter
New air filter
Cleaned carb twice (absolutely positive the jets are clear)
New fuel filter
New fuel lines (from petcock to carb and engine intake)
Reset valves to .08
New petcock
Checked vacuum lines (seem to be ok)
Idle screw on throttle assembly is bottomed out--no more adjustment available

What next? Any help would be appreciated...Thanks!

Post by **jrsjr** » Wed Aug 16, 2017 1:19 am

I've been fooled before by intermittent electrical gremlins and once by a stuck valve, but this sounds for all the world like a carb problem. I see that you cleared the jets, but there are also internal passages in the body of the carb. Did you soak the carb in solvent and blow out those passages with compressed air?

OKMatt · Post by **OKMatt** » Wed Aug 16, 2017 1:26 am

Yeah, definitely seems fuel related to me as well. I pulled the bowl, float, needle and jets. Soaked the jets and ran a guitar string through them. The rest of the carb I just sprayed and let it sit. Think I oughtta pull the whole thing apart? I didn't go so far as to what you're suggesting.

Thanks for replying...I'll give it a go tomorrow.

Post by **jrsjr** » Wed Aug 16, 2017 1:42 am

OKMatt wrote:Soaked the jets and ran a guitar string through them. The rest of the carb I just sprayed and let it sit. Think I oughtta pull the whole thing apart?.

Yes. Soak the carb body in solvent. Make absolutely, positively certain that all rubber/plastic parts are removed first. Just the metal carb body should go into the solvent bath. Then you are going to need pressurized air to blow through the internal passages.

P.S. That guitar string you used was an E string, right?

Seriously, those carb jets are made from soft metal so be a little careful with the guitar string trick.

OKMatt · Post by **OKMatt** » Wed Aug 16, 2017 1:46 am

Martin, high e. Medium gauge

I did try to take it easy but I'll just use air in the future.

DeeDee · Post by **DeeDee** » Wed Aug 16, 2017 2:21 am

Are you sure the vacuum diaphragm is seated properly? It can look correct, but often isn't.

OKMatt · Post by **OKMatt** » Wed Aug 16, 2017 2:28 am

Ok, now my ignorance is going to show...I'm a rookie with all this. The diaphragm that you mentioned, is this in the carburetor? I didn't break it down that far when I pulled it.

Post by **jrsjr** » Wed Aug 16, 2017 3:38 am

OKMatt wrote:Ok, now my ignorance is going to show...I'm a rookie with all this. The diaphragm that you mentioned, is this in the carburetor? I didn't break it down that far when I pulled it.

Ah, here you go. This is our best thread on that, I think.

BuddyRaton · Post by **BuddyRaton** » Wed Aug 16, 2017 2:04 pm

OKMatt wrote:Ok, now my ignorance is going to show...I'm a rookie with all this. The diaphragm that you mentioned, is this in the carburetor? I didn't break it down that far when I pulled it.

Good advice on carb rebuild. Take it all the way apart, soak in carb cleaner, blow everything out. Keep us updated!

Post by **jrsjr** » Wed Aug 16, 2017 3:26 pm

Because of an editing error, I accidentally didn't post the blow-up diagram of the carb that I meant to last night. Here it is:

Syd · Post by **Syd** » Wed Aug 16, 2017 6:02 pm

Pay close attention to parts numbered 3 - 8. Extra care is needed when reassembling those parts.

ucandoit · Post by **ucandoit** » Wed Aug 16, 2017 7:00 pm

Also, make sure the float height is correct. If too high, it will flood the carb. The scoot will stutter and miss.

OKMatt · Post by **OKMatt** » Fri Aug 18, 2017 2:05 am

Ok...

Let everything soak and blew it out with compressed air. Put it back together and, voila, I have idle.

Now, not much power. I had power before taking this all apart. It's just that it surged between 0-20. Now it bogs when you first hit the throttle and it has very little giddyup. 25mph fully pegged.

Do you guys think I missed something putting it together? I had pulled the fuel/air screw all the way out to clean...after reinstalling I tried to adjust when idling but couldn't feel any difference. Still wants to bog whether running really lean or really rich.

Also, if I set my valves too tight will that cause a loss of power? Reason I ask is because today is the first day I've ridden since resetting.

It's getting late here so no more working on it tonight...

OKMatt · Post by **OKMatt** » Fri Aug 18, 2017 3:23 am

As I'm looking at the diagram, I'm starting to wonder if I crossed up the order of parts 4 and 5. Will check again tomorrow. I also noticed that the throttle was way easier to turn after reassembling.

OKMatt · Post by **OKMatt** » Sat Aug 19, 2017 12:52 am

It was as I had thought. I installed parts 4 and 5 out of order.

Put it back together and, dangit, back to no idle. Pulled the whole thing apart AGAIN and verified everything inside. I went ahead and put a bigger idle jet in that I had ordered (42) and it barely idles with the screw all the way down. The only way to keep it idling is to tweak the throttle adjustment.

Suggestions from here?

Post by **jrsjr** » Sat Aug 19, 2017 2:42 am

OKMatt wrote:Bought a 2006 Buddy 125 that had been sitting for a year. After much work, I can't get the scooter to idle and it surges between 0 and 20mph. After that it lines out. Let off the throttle at a stop and it dies. Below is a list of things I've done so far:

New battery
Drained gas tank
Changed oil and oil filter
New air filter
Cleaned carb twice (absolutely positive the jets are clear)
New fuel filter
New fuel lines (from petcock to carb and engine intake)
Reset valves to .08
New petcock
Checked vacuum lines (seem to be ok)
Idle screw on throttle assembly is bottomed out--no more adjustment available

OKMatt wrote:Let everything soak and blew it out with compressed air. Put it back together and, voila, I have idle.

OKMatt wrote:It was as I had thought. I installed parts 4 and 5 out of order. Put it back together and, dangit, back to no idle.

So, with parts 4 and 5 reversed, you had idle. That means... when the main jet needle is riding way too high - it idles. I'm out of my depth here in CV carb troubleshooting. Can somebody pls tell us what this means? Somehow this carb has gotten seriously out of whack and I'm afraid I'm making the situation worse.

k1dude · Post by **k1dude** » Sat Aug 19, 2017 4:26 am

I'm wondering if it's just easier to buy a new carb.

Post by **jrsjr** » Sat Aug 19, 2017 4:35 am

k1dude wrote:I'm wondering if it's just easier to buy a new carb.

Easier, maybe, but not cheaper. They're $227.

babblefish · Post by **babblefish** » Sat Aug 19, 2017 5:10 am

jrsjr wrote:
k1dude wrote:I'm wondering if it's just easier to buy a new carb.
Easier, maybe, but not cheaper. They're $227.

Actually, as low as $115 shipped on eBay...

babblefish · Post by **babblefish** » Sat Aug 19, 2017 5:23 am

OKMatt wrote:Ok...

Let everything soak and blew it out with compressed air. Put it back together and, voila, I have idle.

Now, not much power. I had power before taking this all apart. It's just that it surged between 0-20. Now it bogs when you first hit the throttle and it has very little giddyup. 25mph fully pegged.

Do you guys think I missed something putting it together? I had pulled the fuel/air screw all the way out to clean...after reinstalling I tried to adjust when idling but couldn't feel any difference. Still wants to bog whether running really lean or really rich.

Also, if I set my valves too tight will that cause a loss of power? Reason I ask is because today is the first day I've ridden since resetting.

It's getting late here so no more working on it tonight...

Take the black plastic cover off and verify that the lip of the rubber diaphragm of part #3 is seated correctly on the carb body. To make sure it's seated well, get some silicone (nothing oil based!) lubricant (not too much) and apply it around both sides of the rubber lip before screwing down the plastic cover. Even a pin hole leak here will wreck havoc with fuel metering. If you find that it's been pinched and damaged, you'll have to buy a new "vacuum piston", p/n 14029232201 ($28.) through a dealer or places like scooterloungeonline.

Worst comes to worst, replacement 24mm carbs on eBay can be bought for around $115 shipped. Don't get the one's with the shiny metal top cover. They do not perform as well as the more expensive black plastic capped versions.

az_slynch · Post by **az_slynch** » Sat Aug 19, 2017 8:53 pm

The original issue sounds a lot like a pilot circuit issue. The idle jet may be clear, but the pilot circuit is what works with the idle circuit to fuel the engine when the vacuum piston is seated full down to nearly halfway up.

Pull it down to the bare carb body again and look for the little port in the floor of the venturi (big passage through the middle of the carb) near the throttle plate (brass valve). You may need to hold the throttle partially open to get to the pilot port. Thread your guitar string down through there if possible. Once you've rodded what you can, you might look at the carb body casting from the bottom (what would be the top of the float bowl). See if you can find the casting for the channel between the pilot port and idle jet housing. This will be tricky to clean. If you can get the guitar string it, excellent. If not, work at it with an aerosol carb cleaner (wear crappy clothes and safety goggles or a face shield) or try canned/compressed air.

A possible reason as to why you had idle the second time is that your main fuel needle was set too high by the assembled out-of-order parts and you were probably pulling fuel up the needle from the main jet; was working like an older carb without a pilot circuit. Once you opened the throttle, the needle position was too out of sorts for proper air/fuel metering and it was bogging. Alternatively, your vacuum diaphragm was improperly seated and not lifting the throttle piston...or the improperly positioned needle was allowing too much vacuum loss through the piston and preventing it from drawing up properly.

I have a Buddy carb in the garage, I'll see if I can get a picture of the pilot port a little later.

Addendum: I noticed on the diagram that the Buddy carb has an accelerator pump circuit. When you had the carb bowl off, did you clean the accelerator pump ports? There's a small port in the bottom of the carb bowl near the pump and a jet-like orifice on the lip of the carb bowl, near the accelerator pump rod. Put a little fluid in the bowl, enough to cover the lower orifice. Push down on the pump rod a few times, it should squirt out the upper orifice. If that's plugged, your off idle acceleration will be stumbly. Still won't cover for the idle issue, but it can add to your problems.

Post by **jrsjr** » Sat Aug 19, 2017 9:51 pm

Thank you so much az_slynch! I thought I had a pretty fair idea how the Buddy carb worked until the OP posted that stuff about the bike idling when it was assembled wrong and then I realized I was out of my depth.

Thank you again for coming to the rescue!

OKMatt · Post by **OKMatt** » Sat Aug 19, 2017 10:59 pm

Az_slynch, thank you so much. Ill give it another whirl tomorrow. I did clean the accelerator port after I soaked it. Blew it out with compressed air.

I was getting so frustrated that I began shopping for a replacement. So expensive.

Thanks to all of you for helping. I'm pleasantly surprised by how responsive you guys are.

az_slynch · Post by **az_slynch** » Sun Aug 20, 2017 2:47 am

Keep us posted. Looked at the carb in my garage, it has a very simple pilot circuit. I'll see how hard it is to rod out, but I don't have guitar strings, just a set of small reaming tools.

Post by **jrsjr** » Sun Aug 20, 2017 2:57 am

az_slynch wrote:... but I don't have guitar strings, just a set of small reaming tools.

Are your reaming tools calibrated? The Martin Medium E is 0.013.

az_slynch · Post by **az_slynch** » Sun Aug 20, 2017 3:10 am

Here's what I have:

http://www.ebay.com/itm/Motorcycle-ATV- ... 2749.l2649

One of the item pictures shows the cleaner sizes as stamped on the back of the case. Not small enough for a #38 pilot jet, though.

Post by **jrsjr** » Sun Aug 20, 2017 3:19 am

az_slynch wrote:Here's what I have:

http://www.ebay.com/itm/Motorcycle-ATV- ... 2749.l2649

One of the item pictures shows the cleaner sizes as stamped on the back of the case. Not small enough for a #38 pilot jet, though.

That actually looks really handy. Thanks for the reference!

az_slynch · Post by **az_slynch** » Sun Aug 20, 2017 3:36 am

OK, grabbed the Buddy carb that was in my garage and popped it apart for a look.

The Buddy carb has three small ports in the bottom of the venturi, directly under the throttle plate. You'll need to prop the throttle open to access them. If you look at the bottom of the carburetor body, you'll see a brass plug tapped in to a chamber connected to the hole where the idle/pilot jet screws in. Those three pilot holes open into that chamber.They probably need to be reamed, plus the horizontal hole at the bottom of the idle/pilot jet housing that connects it to that chamber.

My phone won't focus on them, so I'll need to find my proper camera to document them.

OKMatt · Post by **OKMatt** » Mon Aug 21, 2017 1:39 am

az_slynch wrote: The Buddy carb has three small ports in the bottom of the venturi, directly under the throttle plate. You'll need to prop the throttle open to access them. If you look at the bottom of the carburetor body, you'll see a brass plug tapped in to a chamber connected to the hole where the idle/pilot jet screws in. Those three pilot holes open into that chamber.They probably need to be reamed, plus the horizontal hole at the bottom of the idle/pilot jet housing that connects it to that chamber.

That was it az_slynch! I have good idle for sure. Put the throttle adjustments back to normal and backed the idle screw out.

Next issues are lack of top end (takes about 4 large lot houses to get to 25mph while pegged out) and it seems as though the stator is bad. My new battery won't hold a charge.

I'll double check the diaphragm as babblefish has suggested although I've done that a few times already. Also need to try to tune the air/gas.

Does anyone know if an aftermarket stator is compatible with the Buddy 125? Genuine is really proud of theirs...~$70.

az_slynch · Post by **az_slynch** » Mon Aug 21, 2017 1:47 am

Matt,

This one is the option that most folks prefer:

https://www.scooterworks.com/NCY-Stator ... -P491.aspx

Cheaper than OE and seems to be durable.

Before swapping the stator. Make sure the regulator/rectifier is in good order.

OKMatt · Post by **OKMatt** » Wed Aug 23, 2017 1:34 am

Babblefish, az_slynch and jrsjr

Again, thank you for your advice. The scooter is idling well and after FINALLY getting the diaphragm installed properly I have plenty of power.

I found an awesome video online that shows how the diaphragm and slide are properly installed and verified. Definitely worth watching.

https://www.youtube.com/watch?v=cufBK75uYdg

I had installed a larger pilot jet when I was struggling. The bike has a bit of a bog right at the first 1/4 of throttle. I think it might be due to the pilot jet being too large? I'll likely size it down.

Either way, thanks again to all of you that helped me out with this.

Post by **jrsjr** » Wed Aug 23, 2017 2:57 am

OKMatt wrote:I had installed a larger pilot jet when I was struggling. The bike has a bit of a bog right at the first 1/4 of throttle. I think it might be due to the pilot jet being too large? I'll likely size it down.

Glad to hear you got it straightened out! I just got back from seeing the eclipse in Tennessee, but I was thinking while I was sitting in traffic yesterday that I should remind you that you need to put everything back to baseline after you find the problem. I see that you figured it out before I could post...

Happy Scootering!!!