Hello fellow Yamma Dogs
My Big Bear 400 4x4 has been running hot - of course while running long distances and riding like it's a sport bike - bigger tires (27")
I keep the oil changed, oil filter clean, air filter serviced and so on

Any ideas?

 

What symptoms is it having when it is overheated?
Is it going dead or sputtering or ?
Is the oil cooler fan coming on?

 

Ya i have an 02 big bear 400 4x4 with 27 inch vampires all around and i don't overheat yet. I have once but not with these tires. But i also think its cause my snorkel and it might be running lean. I know its probably that causing it to get hot. My fan comes on every day if i ride for about an hour or less at speeds of 25-35mph just cruising around. I think my prob is my snorkel.

 

the fan comes on when needed, but the oil light has been coming on, usually after a hard ride.
the engine does not studder or stall, but it "feels" hotter than usual

I should also say I have always used YamaLube oils
have a K&N and Supertrapp pipe
I took it to the dealer to adjust the jets.

any thoughts?

 

we have a bigbear, its all stock but the fan hardly ever comes on. we have never had any problems with overheating, and it is normally run pretty hard for long periods of time. i don't know what could cuase it to overheat, i've never experienced that problem

mini

 

I too had that problem, so I got some of the exhaust pipe fiberglass heat wrap and wrapped the exhaust. I also got a sheet of the manifold heat deflection fiberfoil stuff, and put it on the bottom side of my seat. Lastly, i got a neopreme seat cover from Cabela's for $20.00. this has made all the difference after a long hot summer run....the heat stuff came from "Thermo-tech", off a link to 24/7 auto parts if i remember correctly. wrapping the exhaust made the biggest difference. good luck.[img]i/expressions/face-icon-small-cool.gif[/img]

 

thanks for the info Tackleberry
I'll look into that, maybe the pipe is the source, kinda makes sense...

 

if THAT aint it, you might have the carb checked for proper jetting, I've heard they can sometimes run rich...I've also heard that some carbs aren't tight at their attachment, loose bolt, or something like that. Also, a good coating of MUD (paint) cools it down....lol..good luck

 

Thanks again, Tack.
I will check the carb attachment -
It was jetted by the Yamaha Dealer when I put the pipe and K&N on,
but that was some time ago - I have been thinking the packing in the pipe
(Supertrapp IDS 2) has burned up with all the riding I did on it, less back pressure would change things, too
Thanks again for the help,

Gary C