Cold air intake

[tinman]

I have modified the air intake on my OX so now am getting the air to the engine from outside the engine compartment. This has really improved the performance of the machine. The mod was easy enough ( I am not the most mechanically inclined person you will meet) Took a 6 in to 4 in reducer for a heater vent mounted it on the air filter housing, after cutting out most of the end of the housing. Then took an adjustable 90 degree 4 in elbow removed one section and attached it to the reducer, Removed the back of the seat so I could mark where the air intake would contact the engine cowling. Then took a 4 in hole saw, cut where the intake met the cowling. Used metal tape to seal all attach points and the other end of the air intake. I used a 4 in heater vent from a rv for the cover on the intake. Rich with Alaska Mudd Ox had measured the air temp at the intake after 20 min run time at 140 degree F. He figured we were losing about 35 -40 percent of the power from the engine. I will post pictures in the gallery under Mudd Ox cold air intake.
Tinman

[akexpress]

Nice job Mike it allows the engine to maintain more horsepower even when the engine bay heats up. You can get a better understanding if you search for air density charts, there is a mathematical formula for horsepower loss based on combustion air temp and altitude , it really gets bad when you combine two. This info applies to any of the amphibs. I am now working on a ducted fan for the carb body which should help with hot start issues some machine experience. I will post more info when testing is complete but the results look very promising so far. The cold air intake is now standard from the factory on new machines.

[yamadog]

Mark is there a cold air intake kit avaiable. Emailed and called matt but got no responce. Thanks

[akexpress]

Yamadog
there is a cold air intake kit now available but it is very easy to fab one yourself in fact all but 2 of the machine in alaska have made their own. Take the outer cover off of the air cleaner on the rear engine cover side and take it to home depot and get some of the ducting that fits over it (7 inch if I remember right) cut notches for the latches and cut out around the lower part to match contour on the underside. You want to seal as much hot air from getting in to the intake as possible. Cut the outboard end at an angle to match the angle of the rear engine cover. You can make some slits in it and flare the end and place some weather stripping on it to form a seal. I attach it the air cleaner cover with a couple of screws and it just rests against the engine cover. Cut a 3-4 inch hole in the engine cover about 25inches up from the bottom and cover with screen and you are done. I also drill open the end of the air cleaner cover to allow even more cold air into the engine. also if you insulate the fuel line and move the electric fuel pump back to the tank it will help with hard start issues.
enjoy
Mark

[yamadog]

Thanks Mark, I'm glad you're always willing to help with an honest answer. God Bless

[yamadog]

Hey Mark, got my cold air intake fixed today. I wanted to drill air intake to open it up even more but was not sure where you were talking about exactly. Also would like to know where fuel pump is so I can move back to the fuel tank. Thanks again for all your help.

[akexpress]

I open it up below where it says Kohler on the end of the filter cover. You can only move the fuel pump if you have the electric pump then move it to back with the tank. You need to run a hot wire back there (splice into a red wire with a white stripe(ignition controlled) and ground to tank. The fuel pickup is on the passenger side of the tank the fitting on top is the vent hose. I make a bracket out of aluminum to hold the fuel pump and attach to rear body area. Insulate the fuel line in the engine bay for max benefit . You will notice a big difference in power after the engine heats up with the cold air intake.

[yamadog]

You where right Mark. Made the first run today after cold air mod, man what a difference that made. Very little diff in power from start to finish. And it was 94 today in SC. Taped up fuel lines but my fuel pump looks like it is made into the engine. Didn't know if that one could be moved or not. My ox is the secound or third one off the line. There are four little bolts holding it in place. Do you know if that one can be moved. thanks

[Cougar]

You where right Mark. Made the first run today after cold air mod, man what a difference that made. Very little diff in power from start to finish. And it was 94 today in SC. Taped up fuel lines but my fuel pump looks like it is made into the engine. Didn't know if that one could be moved or not. My ox is the secound or third one off the line. There are four little bolts holding it in place. Do you know if that one can be moved. thanks

That fuel pump is the stock one and it can not be moved. The pump on mine is a ele. one and thats the one that there are moving to the back. hope this helps. Cougar

[yamadog]

Thanks Cougar, can that pump be bypassed and another pump installed? Also was wondering how your new ox is doing?

[akexpress]

Yes you can bypass the mechanical pump and in stall the electric one. This has the added benefit of giving you redundancy on a trip. The electric pump seems to work better as a push pump so it works better at the tank end and also keeps it out of the heat area.

[Cougar]

Thanks Cougar, can that pump be bypassed and another pump installed? Also was wondering how your new ox is doing?

I haven't had much time to ride. I did get to go with Matt at Bundy Hill before I went in for surgery. I hope to be back riding in the next 2 weeks. What riding that I have done, I love the OX it just blows my old conquest away. When I get back to riding I will take lots of pics. Cougar

[yamadog]

I was wondering what type of pump and where can I get one. Also do I just plug the old one thats on the engine.

[akexpress]

it is just an electric fuel pump that runs at 2 psi I believe. You will need to run a possitive wire back to the tank area and it should be ignition controlled so just tie into a red wire with a white stripe as they are ignition controlled. there is one near the fan relay on the passenger side that is easy to get to. You can ground to the fuel tank. Just run a piece of fuel line in a loop from the intake to the output on the mechanical fuel pump. If you plan it carefully and make the hoses the right length it is easy to switch from one to the other in the field if the electric one ever failed. You can order the Kohler electric pump from any Kohler engine dealer if you want the exact one. I will see if I can find the part number for you later today.
Mark

[yamadog]

Thanks Mark, you da man!!