i have a '88trx310r and its modded a bunch. Some ppl have told me to remove the overflow and re-route the overflow hose over the pipe, then when it overheats u hear/see it sizzle and u know its hot. other ppl have told me to keep it so when the motor is cool more coolant will stay in the radiator and when its hot it may overflow, but when it cools it will go back. i was just wondering what everyones opionion is on what i should do?

 

I'm not familiar with the 250R design, but in general removing the overflow would be a very bad idea. The overflow is a reservoir that coolant flows into when it gets hot and sucks back out when it cools down. Without the reservoir you would spew coolant out when it warmed up, but would never get it back. You would be running very low on coolant after a short time.

 

take it off...all it does is catch expanded fluid....

 

The LT250R's(quadracers) didn't use an overflow, do Banshee's?
ERIC

 

The banshee does use a catch container for overflow..... I don't think I would reccommend this...But at local hair scrambles...alot of the racers route the return line up to the handle bars. When the machine starts spitting fluid, It ends up on your hands. I would not think this is the safest thing to do...But alot of the guys claim it is the only way to tell when they are overheating during a long race.

 

i have to say leave it on i have on my 88 tecate that i race motorcross in michigan. if it overheats you can still run the overflow tube the pipe ,and still have the extra fluid in the tank.
if you take it off theres no extra fluid to spare if you ever need it.

 

the bottle doesn't return the fluid to the radiator anyways, unless it can somehow defy gravity and make its way back out the cap...

 

Dill, you better take a look at you bike because the radiator connects to the bottom of the coolant bottle. The hose on the cap is a vent line.

As far as a need for it, depends a lot on the type of riding you do. Most MX people scrap it for weight and the fact they maintain pretty consistent speeds to provide ample air flow through the radiator. Therefore, the motor is more forgiving to not having it on the bike. Also, most of the Pro's run aftermarket chassis and not all of these chassis have mounts for the coolant bottle. Also, others in the non-pro classes see the pros not using them so they scrap theirs without any thought as to why. The Pros also check coolant levels between motos.

Most woods racers will have the coolant bottles. In this type of riding, the speeds change more, hence airflow and engine temperature. In this case, having and coolant bottle becomes more important to provide for expansion and contraction of the coolant volume in the radiator. These races last 2-3 hours vs. 30 minutes for a MX moto. You also don’t get an opportunity to check the level in the radiator as often.

If you are just trail riding, there is absolutely no reason to take it off.

 

Dill ever heard of hot expanding and cold contracting thats how the bottle works with a sealed coolant system.
unless you have an unlimited supply of anti-freeze coolant at the track or riding sight you better keep that bottle on your quad !

 

well, its been awhile since I took mine off. once you fill up the radiator, you will get a little that spits out due to thermal expansion, after that, its good to go. I've ran my bike wide open for a long long time at SL (Silver Lake) sand dunes in 100 degree heat, and it didn't overheat or spit out fluid, about the only time it will spit fluid is when going very slow (1st gear) the only thing you have to do is check the fluid level every once and awhile, it WONT be to the top to the radiator when cold (thermal expansion) and keep an eye on it, just like you would even if you had the catch bottle, it is just general preventative maintenence.