Carburetor for a 150cc znen joker clone?

MClara · 07-13-2016, 08:59 PM

I've had a znen 150 for a couple of years now--this is my third summer. It was having a heck of a time starting and initial acceleration was flat. I took it to a local shop and they got it running somewhat better--said they cleaned the carburetor, twice, with ultrasound. But it's far from optimal and they said a new carburetor would take care of it. They said the cause of the problem is ethanol in the fuel and recommend I add a stabilizing enzyme to every tank of gas. They want $80 for the carburetor, plus labor, which will make it as much as $160. I looked around online and the most expensive carburetor I can find for a GY6 (which is what I've got, right???) is about $40, so their costs seem more than a little high. Maybe I should do it myself? What carburetor should I get for it, and from where? Thoughts on what this shop wants to charge me? Maybe they're right on the money, what do I know...

Here's the scooter:

Here's the specs:

Engine/Drive Train
Displacement: 149cc, 4-Stroke
Horsepower: 8.4 hp
Max Torque [n.m/(r/min)]: 6.7/5400
Cooling System: Air Cooled
Transmission: Automatic
Drive: Belt
Starter: Electric / Kick Start
Ignition: 12 V 7AH
Top Speed: 55+ MPH (Depending on Riders Weight and Road Conditions)

Thanks!

rks · 07-14-2016, 07:25 AM

Our scooters are similar in appearance, and identical in the specification department.

If you can do it yourself, then that's the way to go. You can get a new, 24mm gy6 carburetor from any number of places, delivered to your door, for $25. If you have doubts about your mechanical skills, maybe a more experienced friend or family member could lend a hand.

The shop was right about the ethanol......I run nothing but ethanol free gas.....certain you could find it somewhere in your area. It's more expensive, but worth it to me.....with over 10,000 miles on my scoot, the only thing I've done to the carb, is replace the auto enricher.

MClara · 07-16-2016, 09:09 AM

Quote:

Originally Posted by rks

The shop was right about the ethanol......I run nothing but ethanol free gas.....certain you could find it somewhere in your area. It's more expensive, but worth it to me.....with over 10,000 miles on my scoot, the only thing I've done to the carb, is replace the auto enricher.

Hey, thanks for the response. I'm curious, how come other small engines don't have the same problems with ethanol as my scooter? My lawn mower is five years old, I stabilize the gas in the fall, but other than that, I don't worry about it, and it starts and runs the same as when it was new.

Irish · 07-16-2016, 03:13 PM

A few yrs. ago , one of my co-workers had worked for the State in the previous yr. He said that at the end of the workday , they would empty every machine. Otherwise the additives would separate overnight & the engines would burn up. Also they would shake the machine before starting in order to mix-up the fuel. This probably will not help with your problem but the lawnmower statement made me think of it.

Irish

rks · 07-16-2016, 06:20 PM

Most small engines do suffer using ethanol blends. Some have a better grade of rubber, or similar synthetic material, used in their fuel systems. This means everything, from the cap on the tank, to the intake manifold. My 2005 Cub Cadet ( which has 1,175 hrs on the clock) has seen a lot of 10% blended gas, and not suffered much....although last year I discovered the gasket on the fuel tank cap had turned into gum. Other small engines I own (chain saws, string trimmers, roto tillers) have all had fuel system failures much quicker. Our later model cars don't have a problem with it......unless it sets unused for extended periods.

I'd bet any (honest) small engine repair place will tell you the same......Just ask them the number 1 cause of failure in equipment they see.

Question: Does this scooter have the damn canisters, and all of the associated emissions hoses still attached?

Shadowfire · 07-17-2016, 01:07 AM

Ethanol shouldn't be a problem in any gas powered device that's been out for more than 2 or 3 years. Every manufacturer that sells in the USA knows about it and what they need to do for it not to be a problem. Even the Chinese scoots are now using DOT-approved fuel lines.

What IS going to be a problem, though, is moisture in the fuel. If the bike sits for a long time, ESPECIALLY if its kept outside, moisture gets into the fuel. This causes the fuel to thicken/goop, or "cottage cheese"/"varnish". When it happens inside the carburetor, the varnish WILL narrow or completely plug up carburetor jets and passages. If left alone for years this way, it will actually damage/eat away the brass parts (jets, passage sleeves), and at that point a new carburetor will be the only fix, since you can't unscrew a physically damaged secondary jet aerator or passage sleeving to put in a new one.

I've seen sources that say that varnishing is actually due to the additives in gas, not ethanol. I'd tend to believe that, because its well known by the old timers about how bad fuel storage times are compared to years gone by. As far as I'm concerned, it doesn't matter what the actual cause is, just make sure you don't let the bike sit with a carburetor full of gas for more than a few weeks.

As for the OP, if they ultrasonically cleaned it and it still isn't working, there's really no other option than to replace the carburetor. They tried the cheap fix, but the carburetor was beyond repair. As to whether or not to have the shop do it, that depends on your skill with a wrench and your tolerance for tinkering. If you have the shop do it, they are also on the hook for making sure that the carburetor is tuned properly. If you do it, then it becomes your problem to make sure that the air/fuel adjustments are correct for your bike.

07-14-2016, 07:25 AM	#2
rks Join Date: Dec 2013 Location: Western New York Posts: 454	Our scooters are similar in appearance, and identical in the specification department. If you can do it yourself, then that's the way to go. You can get a new, 24mm gy6 carburetor from any number of places, delivered to your door, for $25. If you have doubts about your mechanical skills, maybe a more experienced friend or family member could lend a hand. The shop was right about the ethanol......I run nothing but ethanol free gas.....certain you could find it somewhere in your area. It's more expensive, but worth it to me.....with over 10,000 miles on my scoot, the only thing I've done to the carb, is replace the auto enricher. __________________ 2011 Jonway 150cc..16,109 breakdown free miles, and counting
	0

07-16-2016, 03:13 PM	#4
Irish Join Date: Dec 2014 Posts: 738	A few yrs. ago , one of my co-workers had worked for the State in the previous yr. He said that at the end of the workday , they would empty every machine. Otherwise the additives would separate overnight & the engines would burn up. Also they would shake the machine before starting in order to mix-up the fuel. This probably will not help with your problem but the lawnmower statement made me think of it. Irish
	0

07-17-2016, 01:07 AM	#6
Shadowfire Join Date: Feb 2015 Posts: 121	Ethanol shouldn't be a problem in any gas powered device that's been out for more than 2 or 3 years. Every manufacturer that sells in the USA knows about it and what they need to do for it not to be a problem. Even the Chinese scoots are now using DOT-approved fuel lines. What IS going to be a problem, though, is moisture in the fuel. If the bike sits for a long time, ESPECIALLY if its kept outside, moisture gets into the fuel. This causes the fuel to thicken/goop, or "cottage cheese"/"varnish". When it happens inside the carburetor, the varnish WILL narrow or completely plug up carburetor jets and passages. If left alone for years this way, it will actually damage/eat away the brass parts (jets, passage sleeves), and at that point a new carburetor will be the only fix, since you can't unscrew a physically damaged secondary jet aerator or passage sleeving to put in a new one. I've seen sources that say that varnishing is actually due to the additives in gas, not ethanol. I'd tend to believe that, because its well known by the old timers about how bad fuel storage times are compared to years gone by. As far as I'm concerned, it doesn't matter what the actual cause is, just make sure you don't let the bike sit with a carburetor full of gas for more than a few weeks. As for the OP, if they ultrasonically cleaned it and it still isn't working, there's really no other option than to replace the carburetor. They tried the cheap fix, but the carburetor was beyond repair. As to whether or not to have the shop do it, that depends on your skill with a wrench and your tolerance for tinkering. If you have the shop do it, they are also on the hook for making sure that the carburetor is tuned properly. If you do it, then it becomes your problem to make sure that the air/fuel adjustments are correct for your bike.
	0