Chinese Carb Success(?)

[Wheelman-111]

Greetings:

For over 4000 miles since MeatBall sent me a 34-mile AF16, all we've done is put premix in the tank and ride it.
Lately it had gotten fussier to start, then wouldn't hold idle once it did, and refused throttle unless given quick flicks until the revs came up.
I installed Noisy-Guy's awesome filter (added 12 MPH before... ) and it improved for a bit.
Symptoms returned, and a new plug didn't help.
The Clue was that I was getting it to run a little better closing up the air screw - a sure sign of a Pilot Jet becoming increasingly clogged.

A long time ago, for reasons I don't recall (morbid curiosity? Spare parts?) I bought a Chinese PA clone carb. It was under $30. It sat on my workbench for almost 2 years after a brief inspection.

Now that I had to give the Honda carb a Berryman's Bath, it seemed a good time to see if all the negative scuttlebutt about these things was true.
So I installed it.

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The main issue was that my throttle cable now had a ton of free-play. Different cap design. Adjusted throttle cable almost all the way out. I toyed with the idea of swapping the Honda throttle slide and enrichener, but eventually left the Chinese ones on. The Chinese needle is considerably thinner than Honda's - another reason to leave it in...The only thing I did swap in was my Keihin 90 main jet. Fortunately, it fit.

Once primed, it fired up. I had to back the throttle stop down, and adjusted the air screw to 1-3/4 turns out from seated. (The Honda had gotten to 5/8 for it to run at all...) Too rainy for a real test ride, but dodging showers down the street and back the bike's "personality" was different. When you ride a scooter several times a week for this long, you can feel the difference. I can describe its behavior as more "Coarse", but it did run pretty well.

I'm not sure how and why these carbs got bad press. Maybe the plastic bits dissolve, or the floats fill with gas, or the float needle valves eventually start leaking. I'll run it as long as it runs as well as it did today and post back. (The Honda PA should be clean soon.)

[Meatball]

I picked up a basket case Spree for quick flip that had no carb. Instead of investing in an oem, I optd for a chinese ebay carb for about $22. For starters, the mounting flange to the intake was not flat. So bad that the o-ring would not seal so I needed to slather it with Hondabond.
Next, the slide was sticky. Upon investigation I determined the barrel had major casting flaws so I needed to run a dremel down there a few passes and then polish it.
The final straw was when I was changing the main jet. Tightening it down with “finger tip tight” strength and the threads popped out. Soft chinesium metal got me seeing red at that point.

It took $22 and hours of jacking around to validate the ol saying…
”you get what you pay for”.

[Wheelman-111]

Greetings:

Huh!! So far none of those issues on this one. Just the different carb cap thing and needing to adjust the throttle cable almost to the limit. I was pretty tame screwing in the Main. When (If...) the weather improves I'll have more to say.

[Wheelman-111]

Greetings:

Garage Therapy Sunday saw the Honda PA carb pulled from Berryman Bath.
Getting ready:

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I had a plastic tub to minimize mess. No carb cleaner on hand, brake parts cleaner had to do.
Attention turned immediately to the Pilot orifice - the suspected cause of recent misbehavior.
The surgical clamp holds a single steel bristle pulled from an old wire brush. Even the 1st "E" guitar string is too thick.
Poked and prodded half in darkness until I was able to dislodge whatever felt Sticky in that little hole.
Held over a flashlight, I was able to see this:

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I partially stripped a Q-Tip and used rubbing compound to shine up the float needle seat.
My particular carb has a float with a metal tab - adjustable - instead of the all-plastic floats on every other PA I've examined. Weird.
Anyway, valve closes before the float is level. I left it alone.

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I didn't have another proper 90 main jet in my collection. I drilled the Chinese jet out to 90-ish. Fortunately no strippped threads.
Thanks Meatball. I omitted eating my Wheaties for this occasion.
Reassembly was concluded. The longer screws bottom out before they compress the hold-down bracket on the enrichener.

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It will be ready to go if (WHEN?!) the Chinese clone PA starts to act up. So far no Gasoline Lake under Flash...

[motormike]

following...I am sometimes amazed by the amount of resistance that a speck of debris can muster when habitating the microscopic but essential pilot orifice. While I have also taken up various probing utensils, I find that the purposely sized (K&L jet cleaning wire set) to be one of the best additions to my tool box.
At best, the Chinese replacement carbs are a crap-shoot.
One guy never has any trouble with them, ten other guys can't get them to run well.
I've had examples that were installed on Elite 80's that performed well.
I also had examples that installed on Honda Urban Express would never run right.
I hope that the Keihin, once re-installed, will differ from the Chinese by smoothing out that coarse-ness.

[Wheelman-111]

Greetings:

Thanks Motormike! I just want to see and learn for myself what life is like with Clone carb. Won't ride too far from home though...

[noiseguy]

12 mph on those dual foam SA50 filters? I've never heard that before. I stopped making them except on request b/c very few people bought them on the ecommerce sites.

[Wheelman-111]

Greetings:

Those filters of yours are The Bomb, Noisy! Lower resistance with light oiling and keep Flash innards squeaky-clean and happy.

So fired up Flash last night for a quick after-dark run to the USPO. Maybe a 2-mile run to the post-office. Temperature 66, relative humidity 92%. This is very common in Coastal Deepinnaharta, Texas. A little four-stroking for the first 30 seconds or so, then clean, linear throttle response with no apparent loss of Lusty power.

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The speed limit is 45 for part of the trip, had NO trouble keeping up with traffic leaving the lights, but couldn't go faster for traffic.

Anyway, I goes intuh th' Post Orifice for maybe 90 seconds and back out. (Excuse me, I seem to have reverted to Dukes of Hazzard momentarily.)
I usually just use the kickstarter especially when the engine's warm, expecting it ALWAYS to fire with a single kick. No start. Uh-Oh!
Tried a few more kicks with the same result. Tried the starter. Nothing. Hmm. A 2 mile push home?

Now I NEVER gave any throttle when starting before. Not with the stock PA Keihin, Oko, Mikuni or Polini carbs I've had. It's just not done!
But sure enough, like my Orange Vespa - Punkin - the Clone seems to like a little throttle. r-r-Fired up and stuttered for a second then rode home with same impeccable behavior. Really no complaints at all, except it's ... Different. I fiddled a little more with the air screw - seemed to like 1.75 to 2 turns out. Short run around the block this evening, engine temp only got to 213, idle stayed above 2500 tonight. Maybe a bit cooler ambient temp and a WHOLE lot drier. I have not yet begun to fiddle.

That's the news so far. Oh except on the ride home. Remember it was dark? I came within 6 feet of acquiring a Bambi front cover ornament. Crossed left to right. I could hear its hoofbeats over the wind and engine. No helmet of course... Flashed across the headlight beam and Gone! That woulda hurt!!

[Wheelman-111]

Greetings:

Another weird thing with this carb - in a good way. So far since it was installed, the scooter starts when cold on first kick. EVEN when it hasn't run in a couple of days. The PA carb would always "dry out" and it would take 10-25 kicks to prime and start. So far no leaks from the Clone, and it continues to four-stroke a bit until warm, but otherwise seems fine.

[Meatball]

You may have just found the one good carb hut in Shanghai. I would pin that seller for future reference. Nice find Mr Wheel.

[Wheelman-111]

Greetings:

Just under 4 weeks, and fired up with a single kick this morning having sat for 3-4 days. Mystery why this is no longer an issue. Weird that it likes throttle to fire when warm, whereas the Honda would NOT want any. Otherwise: Still runs fine, but I'm NOT selling the Honda PA carb just yet...

[Wheelman-111]

Greetings:

3 months in from replacement with eBay $20 Chinese carb. Still doesn't leak (like my particular Honda PA carb did). Still starts first kick, this time after sitting over a week, although it did threaten to stall before reviving. Also still likes some throttle when starting a warm engine. Hard to describe mid-range behavior, just... Different. Still exceeds 55 MPH given a half-mile stretch. Stock airbox and pipe. 9:1 gears.