Modern Buddy

After test-driving a buddy and everything running perfectly, it stopped working: Almost immediately after paying for it.

the bike can idle, though if you leave it running too long, it will likely die. the problem is when you turn the throttle, it basically dies.

I checked the plug, it's fine. I'd imagine it's an issue that can be resolved with a carb cleaning.

Can anyone confirm what the problem may be? Is this common for Buddys that sit for a season or two?

You can try draining the tank, adding Seafoam and refilling with fresh gas.

Modern gasoline + setting a season or two = Problems.
Something in the carb is gunked up. My guess.
From experience: if you spray carb cleaner into openings, wear safety glasses, it will come out where you don't expect it.

If you don't ride much, use non-ethanol gas, maybe a fuel stabilizer too.
And check for rust and crud in the gas tank.

I rebuilt the carb, and now it 'goes' but only 5-15 miles an hour max.

A Buddy suggested there may be vapor lock from the gastank to the carb.

How do I resolve this? Replace the fuel line, remove and examine the tank?

This symptom is typical when the rubber diaphragm in the carb is not properly seated. Did you remove the cover over the diaphragm when you rebuilt the carb? If so, that may be your problem.

BUMP: bike hits 30 now, but is no where near it's full speed potential. Here's how we got there:

I drained the tank, I pulled/cleaned the fuel tap in some Dawn dishsoap and water. Blew it out a few times, dried it and re-installed.

Replaced the 5/16th fuel line and fuel filter with a Duralast Fuel Filter FF5-16DL from AutoZone
(universal 5/16 filter: https://www.autozone.com/filters-and-pc ... 246932_0_0)

The air filter looks like it's a little old, so I'll likely order another to be delivered later this week but don't expect that to create substantial performance increases.

I'd imagine some fresh high octane gas could help and I may rebuild the carb again to ensure that the float-box diaphragm is 100% secured properly.

Outside of all of these plans, any additional suggestions or checks that I should do?

You should read and pay attention to what vintagegarage says above. Did you bother to read his reply?

BUMP: replaced the rubber diaphragm entirely with next to no change in performance. The old diaphragm looks fine by the way, no tears or scuffs or anything. it wasn't functioning though. We also replaced the air filter. Pickup is practically identical. Top speed is still at 40 or so. It still creeps up hills, much to the chagrin of my fellow commuters as I drive 23mph passing a hilly cemetary in the morning.

Any additional advice? I'm seeing that this bike should be able to go about 55-60, meaning likely cruising around 50 so that I don't redline.

It's very seldom a case of the diaphragm being bad. The problem is getting the diaphragm to seat properly in the groove. It can look fine, feel fine and still not be completely set. Are you sure it is solid all the way around? Where are you?

Not to sound condescending, but if it looks and feels fine how am I supposed to make sure that it's fine?

If you purchased it used, how many miles and overall condition? You could have a transmission issue as well.

oxymoron wrote: ↑Tue Aug 09, 2022 10:52 pm Not to sound condescending, but if it looks and feels fine how am I supposed to make sure that it's fine?

Your vast experience and years of working on scooters tells you this? One that is fine usually hit's 60.

Use waterproof plumber's grease around the lip the diaphragm rests in. Put a light coating on your thumb, and transfer it around the lip. Gently, but firmly work the diaphragm into the groove starting at one point, and contuining 360 degrees around. Place the cap on without the spring, and apply firm even pressure downward. Then gently lift the cap and reinstall with the spring. Hold the cap firmly in place while you bring it home with the screws.