Marui Big Bear

spliffnwesson

spliffnwesson

Well-Known Member
A friend gave me a Big Bear to mess with while I'm on house arrest. I don't know if he gave it to me for keeps or what, should probably clear that up.
Since this truck is as old as I am, and as far as I can tell, all stock except for the molex connector I put on.

Since it's as old as it is, some parts aren't working properly.
When I threw in a battery, it took off across the living room and slammed into the tv stand, breaking off a piece of the bumper.
When I took it to the street, it was steering to the left, then would just take off and I couldn't control it.

Seems like an ESC problem?

I got tired of putting the little plastic steering link cap back on it's post (cap and ball fitting) after it hit something.
Plus it was pointless trying to control an uncontrollable vehicle, so I put it away and haven't touched it since.

I want to rebuild it, mostly replace some electronics and get some new wheels n tires, as the stock tires have flat spots from sitting for years.
The motor seems to still be pretty strong as it was popping wheelies when I had control, but I might yank it just to keep the vintage-ness of it in working condition.

Anyone got any advice? parts suggestions?

These aren't my pics, or my truck.. but for a refresher, this is what it looks like...
(I'll try to get some pics of mine later if I can borrow someone's camera)

 
william g

william g

Retired
Moderator
transmitions in them is very fragile, they melt and strip gears easily :ack

The problem sounds like the servo-msc isn't working properly or the radio has a problem sending wrong info (glitch) to the servo.

The old MSC (mechanical speed control) relies on a servo to provide movement and steps and resistors to control speed. They had problems because of heat, and wear. And worked best with a reciever battery for power.
 
spliffnwesson

spliffnwesson

Well-Known Member
The radio seems fine. It's probably the msc.
With the parts I recently ordered, I should have a few extra things kickin around to play with.
I'll probably try to throw my stock WK motor and esc in it and see how that goes.

Is there a way to get the flat spots out of the tires?

It'd be sweet to get it up and running properly, to have a 24 year old truck to run around.
But if it proves to be too much or annoying to work on, I might get rid of it or stick it on a shelf.
 
C

chuukrc

Well-Known Member
Yep, like Will said trannys are very fragile. I had two and both stripped gears due to gearbox melting. I ordered new parts but the same thing happened again.

They were great fun when they were running though. I changed out the ball cups to stop them from popping off when I hit things.

I can see if I have the old tires if your interested.
 
schofield

schofield

Well-Known Member
i have a half built never run big bear, everything but the electronics. no tires as they were flat do have the rims though, if your interested?
 
spliffnwesson

spliffnwesson

Well-Known Member
I have a few other projects goin on. Newer, stronger, faster trucks I want to finish upgrading/fixing/parts-swapping before I get to the Big Bear.

The tranny sounds like a pain, tho mine seemed fine when I ran it.
Also since it's really old, I doubt parts are readily available, if findable even on ebay, so I probably won't be doing anything to this truck for a while.

Thanks for the offers, I'll keep them in mind if I get around to working on this truck.
 
M

MT TRUCKER14

Well-Known Member
Big bear truck

I have 2 big bear trucks 4 hunters and a galaxie. All use the same diff gear. I have the MIp gear kits in both trucks. No more stripping gears. I also changed the stock motor 480rs to the 540 rs. More speed. The stock speed controls are ok as long as you maintain them. You can upgrade the ball end to durbo ball links 2mm. No more poping off ball ends. I plan to make Aluminum bumpers just like the origional when I have the motovation.
 
spliffnwesson

spliffnwesson

Well-Known Member
Yeah, this truck just sits in a corner... not even on a shelf.
It's not mine and I don't know if I have permission to mess with it. I have newer/better trucks to mess with.
 
M

MT TRUCKER14

Well-Known Member
Flat spot tire fix: for fixing flat tires put the truck up on a box or somthing under the chassis that supports it off the ground keeping the tires from touching the ground when not using it. Frequent running will remove some flat spots. You can also spray the tires with armeral tire shine. Something to rejuvinate the tires again. the tire are better than Taymia tires
 
B.M.T.

B.M.T.

Well-Known Member
I have a rerelease Bigbear in bits in a box. I pulled it down about 5 years ago with the intention of replacing the 11x7mm bushes on the back axle with bearings. At $21 a piece, I put it off... and that's where this story ends... so far.

The rerelease came out in 1991. It had a RS540 as standard, and a 3 pinion diff. The spur still spins straight on the 2mm pin with out any bushings/bearings, so it still has a weak spot.

I will put it back together, some day. Probably one of my favorite trucks of all time. Compared to the other 1/12ths out there, it's proportions look so right for a early '80's mt.
 
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