Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 50, 60, 90 & 100 Talk => Topic started by: ian67 on May 24, 2015, 05:17:12 AM

Title: 90M carb
Post by: ian67 on May 24, 2015, 05:17:12 AM

Next question,

how many throttle close springs should be inside the carb?

My carb had 2 throttle closing springs in it, the smaller spring was inside the larger one and around the throttle cable.
I've looked in the manuals and I can only see one spring shown. I suspect the extra one was put in to try to overcome the dried out and sticky grease in the hand-grip throttle mechanism.
Now that I've cleaned and lubed everything I reckon just the big spring will do the job.

Title: Re: 90M carb
Post by: RayK on May 24, 2015, 05:36:17 AM

Ian
The 90 Mtn carb is a 15mm Mikuni. See parts manual on this site for a diagram. Page 6. There should only be 4 springs:
1. Largest on throttle slide
2. Next smaller spring on starter plunger (choke)
3. Small one on top (idle adjust)
4. Smallest on pilot screw.

If you need to discuss please phone me on 02 64522464 or mobile 0437 401 600.

Cheers
Ray

Title: Re: 90M carb
Post by: ian67 on May 24, 2015, 06:39:36 AM

Thanks Ray.
Now i just need to get a new item 3-27 "packing needle seat" and the carb will be right to go.

Ian.