I just recently purchased a 2002 Honda 400EX and I would like to add some extra cooling to it but not sure which option would be the best way to go...

I live in the desert of the Southwest in Las Cruces, NM where the summer temperatures regularly reach into the 90's and low 100's so I figure a little extra cooling couldn't hurt!

My options are:

1. Adding a 2nd, larger, oil cooler on the front of the quad just like the one on this forum post: 400EX Extra Oil Cooler Install - Honda TRX Forums: Honda TRX 450R Forum

2. Adding a Spal 4" Puller fan (147 CFM) on the stock oil cooler like the one in this post: ATV Riders Forum - I got my SPAL fan hooked up today..... scroll down to the bottom, to the post by Wheelie, for pictures.

Ideally I would do BOTH for the best cooling, but for right now I can only afford to do one or the other... Both options will run about $50 each. So which option do you think would give me the most cooling, the fan or the extra cooler?

 

I like the larger oil cooler idea,since it will always do its job no matter what, even if the fan craps out just for the fact it reroutes the motor oil for a longer peroid before re entering the motor.( More oil cool down time).
The Spal Fan can drop dead or a sensor could fail. My Spal Fan died once on my Sportsman also the thermal sensor that tells it to kick on.

Other options are.

Use a higher temp grade of oil would help like 40 or 50 weight rather then 30.
Use Synthetic oil not conventional, it has a higher temp break down tolerance.

Is the the 400ex not a dry sump motor? Thats where the oil is stored in a separate external oil tank and not in the motors crankcase. That in itself acts as one large oil cooler. http://www.atvreviewnetwork.com/enth...hicleCode=1771

 

Thanks for the reply! That is a good point about the fan crapping out vs the oil cooler always there. As for the oil, I just did the first oil change since I bought the quad 3 days ago and wasn't sure when the last owner changed it. I used Mobil 1 15W50 full synthetic oil since so many people on these forums seem to run that same oil. Yes the 400ex is a dry sump, it has an external oil tank. I'm sure it would be just fine without any extra cooling, as long as I don't let it sit idling, but I figured a little extra cooling couldn't hurt just to be safe.

 

15W-50 Syntheic is great for hot days. A dry sump plus a over sized oil cooler will just make it that much better.

My old Yamaha 350 Big Bear had a oil cooler without fan asist but the oil cooler still did its job.

That oil cooler your looking at is 3x larger then most stock ones,I like it.

 

Yeah thats what I was reading, that 15W-50 Synthetic was good for warm weather, or even 20W-50 for really hot days.

I'm definitely going to do the extra oil cooler instead of the Spal fan for now. But I was searching around Ebay and found a 120mm PC Case Fan for only $5 with free shipping that spins at 5300 RPM and flows 220 CFM! Thats even more than the 147 CFM of the Spal fan and at a fraction of the price, so I bought it. The PC Fan isn't going to be water/dust proof like the Spal fan, but I don't ride in water/mud/wet conditions anyway, so I figured for $5 even if it doesn't work out I'm not out much money.

 

No its only the last number that matters at running warmed up temp. 50 is 50.
The first number 15, and 20 are the viscosity at cold start up only, the lower being the better. Thats why its called mulity grade. It has a thickness for cold and hot.
0w is liguid in sub temps while 20W is like jello before warm up.

A do it all oil would be 0w-50 it would start up in the arctic yet handle the hottest desert once to operating temp.



Thats why I used 0w-40 it just has every possibility covered. 0w only comes in synthetic I think.

 

Oh ok! Thanks I did not know that. Good information

 

I'd think as long as you keep it moving it will be fine. I ride a harley and it does fine on hot days, and nothing runs as hot as a harley. It likes it best when I am cruising down the highway and there is lots of airflow. Wintertime is my 400ex's favorite season, it loves these cool temps, pulls harder and is real snappy. But if I was you, I'd do the larger oil cooler and use a heavier weight of oil.

 

Thanks for the reply. I'm definitely going to do the larger extra oil cooler, but I'm also going to try a fan as well. Not sure if you saw my last post but I ordered a 120mm PC Case Fan from Ebay that flows 220 CFM @ 5300 RPM. I know its not going to be water/dust proof like the more expensive Spal fan would be, but I don't ride in wet conditions anyway. Even if the PC fan doesn't work like I hope, it was only $5 including shipping so its not a big deal. As for running heavier weight oil, I just did my first oil change since purchasing the quad a week ago, and I used Mobil 1 15W-50 full synthetic. Do you think I need to run heavier than that?

 

I think that will be fine.