Rhino carb replacement questions

BrandonT · 04-05-2019, 01:27 PM

I bought a new carburetor from WGS to replace the factory one that won’t maintain a consistent idle. And I wanted to put the attached air filter on:
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But the air filter on there is in this weird black plastic housing (red circle).
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And attached to that is a hose feeding back to the motor (yellow arrow).
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What is the purpose of this hose? There’s no way to connect it to the new air filter that I can see. Sorry, this is the first engine I’ve ever worked on before. I’m using this ATV as a learning experience.

Mudflap · 04-05-2019, 01:45 PM

You can just add a length of hose to the crankcase vent so it extends down below the bottom of the engine.

BrandonT · 04-05-2019, 01:48 PM

Okay thx. so it’s a breather for the crankcase? How long of a line? Just long enough so that water doesn’t back up into the crankcase?

Mudflap · 04-05-2019, 01:55 PM

Explanation. As the piston goes up and down it creates pulses of pressure/vacuum. There is also some pressure that gets past the rings and into the crankcase. That hose is a way to relieve pressure so it doesn't build up and blow out the seals. It can just be open to the atmosphere but needs to be long enough that it doesn't suck up dirt when there is a vacuum pulse. It can also spray out a little oil mist so it is routed toward the ground.

Mudflap · 04-05-2019, 01:56 PM

Make it long enough to extend just below the engine.

BrandonT · 04-05-2019, 02:51 PM

Thx Mudflap. That is very helpful. There’s a little elbow on the line going to the crankcase. Possibly a filter. I will install a longer line later today. As for now I have the air filter installed and the carburetor nearly bolted up. But there’s one bolt that is vexing me on the bottom of the intake. It’s hard to get my fingers on it because the carburetor bowl is in the way and I can’t get inward pressure on it to get the threads started. Was a PITA to get off. It’s worse trying to get it back on.

dirtbkr188 · 04-05-2019, 03:17 PM

Is that air filter in the first pic a paper one?

BrandonT · 04-05-2019, 03:28 PM

Okay so I got the carb bolted up. I had to borrow my wife’s tiny hands to get the threads started. I fired it up, and it is indeed better than the factory carburetor was, but it still wants to idle high no matter where I set the idle screw. Is the idle screw captive? Or can it back out and fly off under the spring tension? Also, is there any other adjustments I can do to get the idle RPM down?

BrandonT · 04-05-2019, 03:31 PM

@dirtbkr188, no it’s kinda a K&N knockoff. Here’s the link:

https://www.whygostock.com/k-n-style...d-ssr-125-160/

dirtbkr188 · 04-05-2019, 03:48 PM

You have to adjust the fuel screw to compensate for the now too-lean condition due to the screen air filter. The fuel screw is located in front of the float bowl, under the intake. Because it is a fuel screw, you turn it OUT to richen the mixture.

Just an FYI, if you intend to ride the quad through dirt, dust, mud, and water, that isn't the air filter to be using.

BrandonT · 04-05-2019, 04:15 PM

Thanks dirtbkr188. I didn’t know that. The customer service on WGS said it was much better over the other one. Can you suggest an air filter that will fit the now 42mm? The engine now holds a consistent idle, but it’s still way too high. Would moving the needle down one notch help? I got the idle screw backed out pretty much all the way. Seems like it’s just getting too much fuel.

dirtbkr188 · 04-05-2019, 04:48 PM

If you've ever run a lawn mower out of gas, you'll remember that right before it shuts off, the RPMs soar up and then it dies. that is a lean condition, which is why your idle screw is useless.
As far as a filter, I use the UNI Two-Stage foam air filters, oiling only the inner foam with PJ1 spray foam filter oil and leaving the outer foam dry. If you plan on extensive off-road riding, you might want to also use an Outerwears over the Uni filter, as well.

The filter size is indicated with a * and the Outerwears size listed will fit over the UNI.

david3921 · 04-06-2019, 01:52 AM

Quote:

Originally Posted by BrandonT

Thanks dirtbkr188. I didn’t know that. The customer service on WGS said it was much better over the other one. Can you suggest an air filter that will fit the now 42mm? The engine now holds a consistent idle, but it’s still way too high. Would moving the needle down one notch help? I got the idle screw backed out pretty much all the way. Seems like it’s just getting too much fuel.

Some of us found that we have to use the original carbs top cap. The new one holds the cable higher, pulling the sleeve up. The cable doesn't seat all the way into the new cap. It sounds like you have the same issue. Swap the caps and your high idle should go away.

BrandonT · 04-07-2019, 11:43 AM

I will try this, to Dsvid

BrandonT · 04-19-2019, 02:09 AM

Quote:

Originally Posted by dirtbkr188

If you've ever run a lawn mower out of gas, you'll remember that right before it shuts off, the RPMs soar up and then it dies. that is a lean condition, which is why your idle screw is useless.
As far as a filter, I use the UNI Two-Stage foam air filters, oiling only the inner foam with PJ1 spray foam filter oil and leaving the outer foam dry. If you plan on extensive off-road riding, you might want to also use an Outerwears over the Uni filter, as well.

The filter size is indicated with a * and the Outerwears size listed will fit over the UNI.

Thank you dirtbkr188. I had my doubts to your suggestion, but you were indeed correct. I had to use a flexi-screwdriver to get at the fuel air adjustment screw because I burned my hands so many times trying to use a stubby screwdriver. I adjusted the screw in one full turn and the idle screw out a turn and a half. Isles near perfectly now. Just a tiny bit of up and down on the rpm, but I am happy.

04-05-2019, 01:27 PM	#1
BrandonT Join Date: Mar 2019 Location: Kitsap County, WA Posts: 24	Rhino carb replacement questions I bought a new carburetor from WGS to replace the factory one that won’t maintain a consistent idle. And I wanted to put the attached air filter on: But the air filter on there is in this weird black plastic housing (red circle). And attached to that is a hose feeding back to the motor (yellow arrow). What is the purpose of this hose? There’s no way to connect it to the new air filter that I can see. Sorry, this is the first engine I’ve ever worked on before. I’m using this ATV as a learning experience.
	0

04-05-2019, 01:45 PM	#2
Mudflap Join Date: Sep 2014 Posts: 1,889	You can just add a length of hose to the crankcase vent so it extends down below the bottom of the engine.
	0

04-05-2019, 01:48 PM	#3
BrandonT Join Date: Mar 2019 Location: Kitsap County, WA Posts: 24	Okay thx. so it’s a breather for the crankcase? How long of a line? Just long enough so that water doesn’t back up into the crankcase?
	0

04-05-2019, 01:55 PM	#4
Mudflap Join Date: Sep 2014 Posts: 1,889	Explanation. As the piston goes up and down it creates pulses of pressure/vacuum. There is also some pressure that gets past the rings and into the crankcase. That hose is a way to relieve pressure so it doesn't build up and blow out the seals. It can just be open to the atmosphere but needs to be long enough that it doesn't suck up dirt when there is a vacuum pulse. It can also spray out a little oil mist so it is routed toward the ground.
	1

04-05-2019, 01:56 PM	#5
Mudflap Join Date: Sep 2014 Posts: 1,889	Make it long enough to extend just below the engine.
	1

04-05-2019, 02:51 PM	#6
BrandonT Join Date: Mar 2019 Location: Kitsap County, WA Posts: 24	Thx Mudflap. That is very helpful. There’s a little elbow on the line going to the crankcase. Possibly a filter. I will install a longer line later today. As for now I have the air filter installed and the carburetor nearly bolted up. But there’s one bolt that is vexing me on the bottom of the intake. It’s hard to get my fingers on it because the carburetor bowl is in the way and I can’t get inward pressure on it to get the threads started. Was a PITA to get off. It’s worse trying to get it back on.
	0

04-05-2019, 03:17 PM	#7
dirtbkr188 Join Date: Aug 2009 Posts: 520	Is that air filter in the first pic a paper one?
	0

04-05-2019, 03:28 PM	#8
BrandonT Join Date: Mar 2019 Location: Kitsap County, WA Posts: 24	Okay so I got the carb bolted up. I had to borrow my wife’s tiny hands to get the threads started. I fired it up, and it is indeed better than the factory carburetor was, but it still wants to idle high no matter where I set the idle screw. Is the idle screw captive? Or can it back out and fly off under the spring tension? Also, is there any other adjustments I can do to get the idle RPM down?
	0

04-05-2019, 03:31 PM	#9
BrandonT Join Date: Mar 2019 Location: Kitsap County, WA Posts: 24	@dirtbkr188, no it’s kinda a K&N knockoff. Here’s the link: https://www.whygostock.com/k-n-style...d-ssr-125-160/
	0

04-05-2019, 03:48 PM	#10
dirtbkr188 Join Date: Aug 2009 Posts: 520	You have to adjust the fuel screw to compensate for the now too-lean condition due to the screen air filter. The fuel screw is located in front of the float bowl, under the intake. Because it is a fuel screw, you turn it OUT to richen the mixture. Just an FYI, if you intend to ride the quad through dirt, dust, mud, and water, that isn't the air filter to be using.
	0

04-05-2019, 04:15 PM	#11
BrandonT Join Date: Mar 2019 Location: Kitsap County, WA Posts: 24	Thanks dirtbkr188. I didn’t know that. The customer service on WGS said it was much better over the other one. Can you suggest an air filter that will fit the now 42mm? The engine now holds a consistent idle, but it’s still way too high. Would moving the needle down one notch help? I got the idle screw backed out pretty much all the way. Seems like it’s just getting too much fuel.
	0

04-05-2019, 04:48 PM	#12
dirtbkr188 Join Date: Aug 2009 Posts: 520	If you've ever run a lawn mower out of gas, you'll remember that right before it shuts off, the RPMs soar up and then it dies. that is a lean condition, which is why your idle screw is useless. As far as a filter, I use the UNI Two-Stage foam air filters, oiling only the inner foam with PJ1 spray foam filter oil and leaving the outer foam dry. If you plan on extensive off-road riding, you might want to also use an Outerwears over the Uni filter, as well. The filter size is indicated with a * and the Outerwears size listed will fit over the UNI.
	1

04-07-2019, 11:43 AM	#14
BrandonT Join Date: Mar 2019 Location: Kitsap County, WA Posts: 24	I will try this, to Dsvid
	0