Snorkle on Honda GX 120

I have a Honda Gx 120 that runs a pressure pump on a spray rig designed to spray Tree Orchards. The problem I am having is that the engine and pump are very close to the ground as the spray rig travels across the field and it is very dusty. After just a few passes through the field, I need to stop and blow out the air cleaner.
I thought one solution to my problem would be to diy myself a type of "snorkel" system to get the air filter up and out of the dusty area.
I took off the air filter and clamped a rigid hose to the collar where the air filter fits in. I extended the hose about 3 feet up and hooked it to the top of the spray rig. I then attached another air filter at the end of the hose. Now the engine runs rough. At full throttle and with the choke open it surges very badly. I can smooth out the surge by either slowing the engine down or closeing the choke about half way.
I can only assume that by extending the filter upwards, I have changed the vacuum or airflow into the carburetor. Is there any way to make an adjustment for this? Is it bad to run the engine at half choke for extended amounts of time?
Thank you for your help

Did you put a K&N style filter on and did you attach the hose well enough to not put pressure on the carb to create an air leak?

Not a k&N Filter. I put this filter on the other end of the hose that I attached to the carb.
https://www.greenpartstore.com/thum...er-element-aw26796-medium.jpg&maxx=300&maxy=0

I have the hose at the carb pretty well clamped down so I do not think there is an Air leak. Are you saying that too much airflow can cause this problem? I was assuming I was creating a restriction.

If you have to use the choke then you are running in a too lean fuel to air condition. The choke cuts off some air and richens the mixture. As long as you are not running overly lean, running with the choke partly closed should not hurt the engine. Too rich might cause some carbon buildup or some gas getting into the crankcase and contaminating the oil.

DBICK said:

Not a k&N Filter. I put this filter on the other end of the hose that I attached to the carb.
https://www.greenpartstore.com/thum...er-element-aw26796-medium.jpg&maxx=300&maxy=0

I have the hose at the carb pretty well clamped down so I do not think there is an Air leak. Are you saying that too much airflow can cause this problem? I was assuming I was creating a restriction.

Click to expand...

I was thinking the weight of the snorkel might be pushing the carb down and causing an air leak at the gasket not the snorkel having a leak. Yes I was thinking you are getting too much air.

Try shortening the snorkle to just enough to connect the air filter. Like 1 or 2 inches and see how it runs.

Thanks for the replies.
I went back out today to take some pictures. I thought it would be easier for everyone to see what I am trying to do. Here is a link to the imgur album:
https://imgur.com/a/BP7a3G5

The engine runs smoothly without the air filter installed. As soon as I place the hose over the collar, the engine either dies or starts running very rough. Even without the air filter at the top, just the length of the hose seems to make it run rough. I tried it with a shorter piece of hose, maybe 1 foot long and I had the same results. The only way I can get it to run a little bit smoother is to close the choke a bit.

If there is no way to adjust the carburetor for this, what else might I try? Is there a different filter/housing that would work in these dusty conditions? Until we get some rain here in California, the field is just so very dusty.

Thanks again for your help

I see problems.

That is a lot of weight pushing down on the carb. I think it might have an air leak behind the gasket. Try holding up all the weight of that hose while it's running and see if it smooths out without the choke partly closed.

DBICK said:

I have a Honda Gx 120 that runs a pressure pump on a spray rig designed to spray Tree Orchards. The problem I am having is that the engine and pump are very close to the ground as the spray rig travels across the field and it is very dusty. After just a few passes through the field, I need to stop and blow out the air cleaner.
I thought one solution to my problem would be to diy myself a type of "snorkel" system to get the air filter up and out of the dusty area.
I took off the air filter and clamped a rigid hose to the collar where the air filter fits in. I extended the hose about 3 feet up and hooked it to the top of the spray rig. I then attached another air filter at the end of the hose. Now the engine runs rough. At full throttle and with the choke open it surges very badly. I can smooth out the surge by either slowing the engine down or closeing the choke about half way.
I can only assume that by extending the filter upwards, I have changed the vacuum or airflow into the carburetor. Is there any way to make an adjustment for this? Is it bad to run the engine at half choke for extended amounts of time?
Thank you for your help

Click to expand...

How did you decide that after a few passes through the field, the air cleaner was so dirty it needed attention? The only accurate way to determine when an air filter element needs to be cleaned or replaced is with a restriction gauge.

The air filter element should be close to the engine, not at the opposite end of the long intake tube. This may be hard to do on an engine that wasn't designed for a commercial-grade air filter system.