Keeping the 400ex cool

[tdsongster]

I have noticed that my 400ex runs real hard when first started and then performance goes down a bit. Is this solely do to temperature? It is a fairly new quad and I took great care in breaking it in.

Also, are there ways to help keep the 400ex a little cooler like:
colder plug
thermal coatings
additional oil cooler
different oil tank
etc

Did I miss some.

I also read an article about a 450R that Bgi Gun had build and they thermal coated(???) the outside bottom half? What is that all about?

Thanks

Tim

[Bush0102]

If only honda would give us a liquid cooled 400 motor!!!

[nosliw]

i would like the aircooled 400 over a liquid cooled one. i like the 400 cause it's nice and simple. i wouldn't like having to walk 20miles back to camp when a stick finds it's way up my radiator/hoses/pump/reservoir

[mojoe2878]

just wondering, but what is your jetting set at?
some people say running synthetic oil helps keeep the engine a little cooler.
i know a good race gas will help the temp. but its not really worth the money on a stock motor.
do you run premium in it now?
if you run a colder plug and it doesnt suit your riding style then it will foul the colder plugs out pretty fast.

[TC426EX]

I have done everything possible to keep my 426 running cool. I race MX, and whenever Im riding it period, its always hard on the gas, so I would have to take a break every so often to give the bike a rest during practice, etc. to keep it from fading. I have added a Quadtech scoop hood, air scoops, and also have added the Mickey Dunlap External oil cooler, and run straight 110 octane. I was a little leery about tapping my rocker and clutch covers to run the cooler but now that I have it mounted up and have tested it, it is proving to be one of the best investments I have made. I am going to experiment with running the cooler plug here shortly and see if there are any fouling problems with it. Another great investment was an oil temperature guage that I got from C+D racing. It replaces the dipstick on your oil tank and has a thermometer built in on top. It is separated up by color as well as number. Up until 50 degrees is blue, then up to 200 or 250 is green and anything over that is red. I now can monitor my oil temp and make sure I keep my bike in the green region. Since adding all these features, especially the external cooler, my oil temps have really dropped noticeably. As far as adding a larger oil tank, its questionable how beneficial that would be. It is true that the higher volume of oil would take longer to heat up, but once you ride for a while all the oil temp. reaches a uniform temp anyway so it really only helps you in the short term...

Get ahold of K_Fulk if you want as well, he knows a guy who does some type of advanced coating to metal components that disspates heat and lowers temps something like 10% or more.

[400exrules]

a few ppl on here have installed computer fans onto there quad that suck the hot air off, and i belive it helped them alot. i forgot who is was tho, so do a search, i know there is a big thread about it

[underpowered]

You can buy larger oil tanks with cooling holes built into them. It is an aluminium tank with pieces of pipe welded through the center creating "holes" to let air flow through and cool the oil better.