Best Honda GX160 Round Slide Carb?

DaddyJohn

Well-Known Member
#1
I've got a Honda GX160 engine that I obtained second hand without a carb or governor on it. It's a decent unit, so I decided to get a Mikuni adapter and bolt a Chinese Mikuni VM22 clone (Chikuni) to it.

What I found was the engine runs okay, but you need to start it with the choke lever off, and set the idle a little high to let enough air in to fire it off (you don't want to pull with the throttle held cracked open if you know what's good for you, lol). Also, it feels a bit weaker down low, then comes on pretty strong up top, though this could just be tall gearing... After awhile though, it'll start missing out, as it's sooting up the plug (from running rich obviously).

So... First question, where do you get jets for these things if I want to proceed to try to tune it?
Second, it this 22mm carb even the best one to be using? Since it's common on 196/212 hop-ups, maybe it's too big?
I could try a PZ19 or PZ20 carb (I have one of each), as those are a bit smaller...

My main goal is reliability and ease of starting vs outright performance gain.
The only reason I'm using a slide carb in the first place is I don't want to make or buy a carb linkage and air cleaner for an original style unit.
I'm usually happy with them otherwise though...
 

Li'l Popeye

Well-Known Member
#2
First: On the chinese mikuni vm22 choke (enrichment device) off, means that the lever (and plunger) is down.
Jets: I have several of these Chinese carbs and they have different kind of jets. Seems that you have to figure out what thread size and pitch the jets have and order the correct jets. I have a Chinese VM22 carb that has original Mikuni main jets (M5x0,75 partnr: N100.604) and Mikuni pilot jets (M4x0,7), but I also have a Chinese VM22 carb that has Keihin main jets (M5x0,8) and Keihin pilot jets (M5x0,8, part nr: N424-74C). And i have a Chinese VM22 carb that has Keihin main jet (M5x0,8) and a Mikuni pilot jet (M4x0,7).
I run GX160's with these carbs without any problems, other than the jet thread size problem. The intake port of a GX160 is about the same size as the carb is. I am sure it will run with a PZ20, too.
 

DaddyJohn

Well-Known Member
#3
That’s very helpful, thanks for taking time to respond! That’ll give some info to try and move forward with.

Anyone else’s experiences are welcome too!
 

DaddyJohn

Well-Known Member
#5
Do yourself a favor and install a genuine Mikuni VM22-133. It made all the difference on my built engine and jets are readily available.

-Ray
I agree that’s going to be the better unit. Before that kind of expense though, I’d just install a new box stock Predator 212 and run with it.

In retrospect, maybe I should have gone the easy route, but I got this GX160 “free” in another deal and thought I could salvage it. And I’m sure I can; it does run well past fueling issues. It’s just an ideal equation of: Hassle + Expense = As little as possible :D
 
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