Picked up a 2006 Big Bear 400 4x4

[redhat]

Sold our 2020 Polaris Sportsman 450 and the new (only had 10 miles on it when sold) 2023 Can-Am Outlander XT 700 last year with the intent of buying a new SxS. I got cold feet... these SxS are cool and very nice, but the $35k price tag and potential to only go out a few times a year made me shy away.

I've been wanting something to do some trail riding and work around the house. Nothing too fancy, but wanted a dead-nuts reliable simple ATV. Came across this 2006 Big Bear 400 4x4 and had to check it out. I've kinda wanted a Yamaha. Original owner, only 750 miles on it, only used around the guys yard for rolling his lawn and pulling a cart. Never mudded, never trail rode, didn't sit out in the sun or rain... always stored inside. Doing the math on the mileage, it seems very accurate. Comes out to less than a mile a week. Guy serviced it and frequently and went by the book -- he also gave me a factory Yamaha service manual for the machine.

It is Clean clean clean, dusty and some plastic scuffs, but the plastics still shine, No cracked plastics, the wheels are like new. I am pleased with the purchase.

Come spring I'll go through it, new plug, change the oil and front/rear diffs. Calls for a GL4 80w hypoid lube in the front/rear. I'm thinking a 75W-90 Mobil 1 GL5 would be suitable. I can't imagine diffs having anything brass/bronze where a GL5 would hurt? Also since I like Mobil I'm thinking 10W-40 Mobil 1 4T in the engine. Can't find many filter choices so I guess I'll go with the OE Yamaha filter.

I welcome any thoughts to dos/donts for my service choices. Here's a couple pics. My first Yamaha and first time I've ever owned an auto-clutch/manual shift ATV. Rode it around a little bit and wow I really like how direct/instant feeling it is compared to CVT/belt drive. It seems more fun to ride honestly to me.

 

[AZjeff]

It looks new! Nice pickup.

 

[daves87rs]

Nice!

 

[Hirev]

That looks familiar. That one looks clean. You should be happy with your Yamaha Big Bear they are tanks. I bought a Big Bear 400 new in 2000 it still runs fine. Don't use it much these days but I keep it around because I don't care for all the new CVT/belt drive stuff. I just use the OEM oil filter and change it about every 2nd or 3rd oil change. Enjoy!

 

[nwjones18]

That's a nice one! I really enjoy my Yamaha 350 Grizzly's. They have the CVT which I actually like quite a bit, but I wouldn't be opposed to having another foot shift. The air cooled motors are rock solid ( I think the 350/400 are pretty similar internally, but could be wrong) PH6607 and equivalent filters work fine. Does that one share oil between trans/motor? If so you have to have something like this that's JASO MA rated for wet clutches: Edit ( I see that Mobil product you listed meets this spec so you're good)

https://www.walmart.com/ip/Valvoline-ATV-4-Stroke-10W-40-Motor-Oil-1-Quart/19514362

I honestly can't remember if I put conventional 80/90 or a synthetic 75w-90 in the axle on mine but whatever it was has been fine. I run 15w-40 Delvac in the motor, but no shared trans on mine.

Enjoy the Quad!

 

[redhat]

Thank you!

I bought some new NGK plugs. Some of that Mobil 1 4T 10W-40 and found a genuine Yamaha filter on eBay for $8. The Yamaha filter is expensive usually $17. It’s a tiny cartridge filter. I also bought a K&N KN142 oil filter off of Amazon for $10. I’ll compare both of them quality wise.

Not opposed to the OE but that’s a lot for a tiny cartridge filter. I cannot find an overwhelming amount of choices.

Air filter I see the OE Yamaha is a paper element with a foam outer. I’ll probably go that route. For an ATV that sees dusty trails, I want excellent air filtration. I do not want a K&N for that.

 

[hemitom]

Nice find ! on a very good quad.

 

[Zaedock]

That's a great machine - nice find! One of our friends has one. Easily kept up during our trip to Hatfield McCoy last year and our trips to Northern New Hampshire.

 

[Number_35]

My team used ATVs extensively 2002 - 2005 while checking out potential routes for terrestrial telecom builds.

We travelled in teams - two quads, and a 4x4 support truck with a winch.

One of the fellows got badly stuck in a swamp, too far in for the truck and mired too deeply for the other quad to help.

A motorsports dealer in a nearby town sent their Big Bear, which towed the little Polaris out with ease.

 

[redhat]

That's a great machine - nice find! One of our friends has one. Easily kept up during our trip to Hatfield McCoy last year and our trips to Northern New Hampshire.

That is Awesome to hear! I do want to go with some buddies to Hatfield McCoy sometime in the coming years. Good to hear the Big Bear keeps up. I know they're not the fastest but they don't seem bad. Plus (maybe I'm getting older) do you really need 1000cc Turbo? Little single sipping fuel might be a good thing.

 

[redhat]

My team used ATVs extensively 2002 - 2005 while checking out potential routes for terrestrial telecom builds.

We travelled in teams - two quads, and a 4x4 support truck with a winch.

One of the fellows got badly stuck in a swamp, too far in for the truck and mired too deeply for the other quad to help.

A motorsports dealer in a nearby town sent their Big Bear, which towed the little Polaris out with ease.

That must've been quite the job scouting those avenues out. Very cool! I love hearing about that kind of stuff. Not to go to far off but the builds/locations/locales of stuff like the AT&T Long lines Microwave relay stations always interests me. Still have one near by with the massive red horns.

 

[Number_35]

That must've been quite the job scouting those avenues out. Very cool! I love hearing about that kind of stuff. Not to go to far off but the builds/locations/locales of stuff like the AT&T Long lines Microwave relay stations always interests me. Still have one near by with the massive red horns.

We had an old microwave system that was coming out of service due to the radios and amplifiers and so on becoming obsolete, and so were under the gun to design a fibre cable replacement. Lots of overtime, and lots of epic time on the quads.

It was a great time, and seemed amazing to be paid well to ride quads.

A lot of the swampy stuff was winter-construction-only. The ploughs would not have made it through the swamps before freeze-up.

 

[nwjones18]

Thank you!

I bought some new NGK plugs. Some of that Mobil 1 4T 10W-40 and found a genuine Yamaha filter on eBay for $8. The Yamaha filter is expensive usually $17. It’s a tiny cartridge filter. I also bought a K&N KN142 oil filter off of Amazon for $10. I’ll compare both of them quality wise.

Not opposed to the OE but that’s a lot for a tiny cartridge filter. I cannot find an overwhelming amount of choices.

Air filter I see the OE Yamaha is a paper element with a foam outer. I’ll probably go that route. For an ATV that sees dusty trails, I want excellent air filtration. I do not want a K&N for that.

Interesting yours has the little cartridge filter then. I knew some of them had it, but both of my 350's have a standard spin on filter (PH6607 size) which is readily available.

https://www.oilfilter-crossreference.com/convert/K-N/KN-142

Looks like Wix and Fram make options, but not going to do much better than $10

 

[redhat]

Those of you with the Yamaha’s. Is it normal the plugs are threaded at the top? Ordered some NGKs and they don’t have the adapter. Doing reading I guess the plug boot has tiny electrodes in it that make contact? Didn’t go thru it yet. Just wanted to confirm.

 

[Fordiesel69]

Those of you with the Yamaha’s. Is it normal the plugs are threaded at the top? Ordered some NGKs and they don’t have the adapter. Doing reading I guess the plug boot has tiny electrodes in it that make contact? Didn’t go thru it yet. Just wanted to confirm.

Yes. Very nice feature as the plug boot will never fall off! But this rules out AC delco and Autolite plugs.

I had the older 2WD YFM350ERT and it was very reliable well past 3,000 miles, but it had a metal defect in the piston which a hunk broke off between the rings due to porosity. It was an easy fix! Engine looked like new inside.

 

[Chris142]

My team used ATVs extensively 2002 - 2005 while checking out potential routes for terrestrial telecom builds.

We travelled in teams - two quads, and a 4x4 support truck with a winch.

Where do I sign up?

 

[Number_35]

Where do I sign up?

A part I didn't mention - working up north for week one winter, and trying to warm my hands by holding them really close to the quad's exhaust system.