1990 Yamaha Big Bear 350 - Throttle Cables

[quintain]

Hi, (Big Bear 350 4x4 1990 +- year, I am still looking for the VIN).

Quad starts and runs and has 2 cables coming out of the throttle cable assembly one goes to the carb the other is not connected.

Where should the unconnected cable be connected to ???

I have a service manual but can only find talk of "Throttle valve cable" and "Piston valve cable" I cannot see where the "piston valve cable connects.

Any help especially with pictures would be good.

[Getch]

Hi There,

New here but was just cleaning the carb on my 1990 Big Bear a few weekends ago. If you cant readily see exactly where that second cable goes I suspect your machine might have a newer carb on it.

On my carb, there are 2 brass "ports" for cables. One on the side for the throttle. One on the top for the piston. One actuates the butterfly, one actuated the recangle-ish piston within the carb body.

Hope this helps!

[oxidized_black]

here's what my '91 looks like with the gas tank and seat removed ....

both of these cables join in a junction box and a single cable goes back to the throttle lever ...

[quintain]

Thanks to you both.

My carb does not have the top connector, the one with the 3 screws holding it down.

My carb looks like your picture but the top piece has no opening.

Any thoughts ??

I can send a pic (later) if it would help.

[quintain]

Hello again

Much dirtier carb top but hopefully you can see what mine is like.

[oxidized_black]

hmmm. i wonder if someone did some custom work on it ???

[quintain]

I'll strip it over the weekend end and see what is under the top !!!

But what should my missing connection do ??

[Getch]

Yeah, your carb is not original but your cables are.

The second cable manually actuates the piston inside the carb body. The kind you have is actuated by vacuum.

search youtube for " yamaha big bear" and there are a couple videos on carb cleaning that shows your style carb.

I believe your carb is just a later model. Not sure if one is better that the other or not but should function just fine.

Edited October 26, 2012 by Getch

[quintain]

Thanks Getch

It could be that the bike is a bit newer than I thought.

I cannot see that anyone would have changed the carb for a newer one.

I have watched youtube on a number of carb cleans and when time permits I will strip it and see whats happening.

I still cannot find the VIN and I am looking in the correct area i.e. frame below or in front of gear shift, I can almost (I think) see some sort of marking on the frame behind the shift.

The bike has had a hard farming life and is banged about and surface rusted. But I hope to eventually get the VIN.

At this moment I am working, when time permits, on the brakes and have just discovered that the bleed screw on the nearside front is damaged so I need to fully strip that down.

Thank you for your interest.

[oxidized_black]

I still cannot find the VIN and I am looking in the correct area i.e. frame below or in front of gear shift, I can almost (I think) see some sort of marking on the frame behind the shift.

The bike has had a hard farming life and is banged about and surface rusted. But I hope to eventually get the VIN.

check where the handlebars go into the frame too ....

[oxidized_black]

I'll strip it over the weekend end and see what is under the top !!!

But what should my missing connection do ??

this is from the service manual ...

[quintain]

Will do.

Email hiccup for the last hour or so, my service provider had a hiccup.

Some messages may have been returned as undeliverable.

All is now good and safe.

Regards

quintain

[quintain]

Thanks o_b

I believe I downloaded your service manual which I am embarrassed to say I did not thank you for; but belatedly I do so now.

As a new user of the or indeed any quad the pic at 4.1 in the service manual did not fully make me aware of the 2nd throttle cable position.

I can see it now including the description of "Piston Valve Cable" on id #8 on the page.

I will be most interested to see what is discovered when I open up the carb. Either a bad alteration or a vacuum operated carb.

Thanks again.

[quintain]

Just for update

These pics of my carb may help someone else.

It is a single throttle cable that operates all that is needed BUT it has been fitted with a twin cable from the throttle assembly with one cable not connected.

The pics show the operating connection with some red tape on it.

Thanks again for help and advice.

"still trying to find my VIN looked everywhere (I think)"

[Fred Washburn]

I have a 1992 big bear 350 who's carburetor has two cables to it; one to the front and one at the top.  I want to install a new carb that requires just one cable to the front.  Which one of the cables do I use from the old set up? [email protected]