400ex overheating

[ssjrmk]

I was just wondering if the Honda 400ex has any problems with over heating while trail riding?

[honda400ex2003]

It mostly depends on what is done to it. i have never had a problem with my 416. From what I hear the most are 440's that are higher compression. Good luck, steve

[honda400ex2003]

Oh and welcome to the site!!! steve

[rideracelivemx7]

i rammed plaenty of air fuel and compression to my 440 and never overheated it

[ssjrmk]

I was wondering what you mean by 440ex. Is that a 400 bored out?

[honda400ex2003]

Yup, it is bored out using a 89mm piston instead of the stock 85mm. The 416 is 87mm, the 426 is 88mm, and the 406 is the 86mm. I believe. By that they calculate the volume in the cylinder with the stroke and bore to get the cc. The 440 has to be resleaved using a different sleeve but the rest can be done on the stock sleeve. The 426 does get pretty slim though on the stock cylinder, I would say that is the biggest heat generator of the bunch but I amm not sure since I have never checked one for myself. If someone has any experience with that let me know anyway. Otherwise if you don't let it run in the same spot for 10 minutes in 90 degree heat or something you should be fine. just remember it is air cooled and you are good to go. I ride pretty hard sometimes and have never had a problem. good luck steve

[jcs003]

if you keep it moving it will run pretty good.(not too hot) if you are just trail riding and stopping alot it will get hot and you will feel a power loss.

some of the guys on here use an auxilery fan and that is a great idea.

[bigbad400]

air shrouds and a bigger oil cooler wil eliminate all heating problems you could ever have on a stock 400ex. a cbr1000 oil cooler is a good one to use. mounts up easy. and is quite a bit bigger and cools much better. but i only have shrouds and have never overheated and i ride the piss outa mine.

[scuzz]

I never had a problem with mine overheating even with my 250 pounds on it trail riding in the middle of August in Texas.

I wouldn't get let it sit and idle though while you're on the trail.

[ssjrmk]

Thanks for all the info guys.

[honda400ex2003]

hey no problem, good luck with it. steve