Running lights out, strange carb damage

[Tupperj]

Hoping to verify a diagnosis. Recent acquisition of an 83, required a wiring harness replacement. Bike came alive and after a few gremlins is running. For some reason, the running lights are out. Bulbs are good, and finagling a probe into the connector on the CMS shows 12 volts on the blue wire from the fuse block, but only 0.8 volts or so out on the blue/white wire for the running lights.

 

Current thinking: bad solder joint in CMS, or bad CMS. Any other thoughts?

 

Three of the four carb covers have silicone dabbed on the middle of them. Taking one off it looks like something ground through the cover, leaving a hole that the silicone is now sealing. Can anyone think of a good reason to do this, or how that could happen without a major crash? Kinda baffling.

 

Thanks all!

 

Paul

[mbrood]

Are you talking about those big aluminum carb diaphragm covers...

(Pay no attention to arrowed items...)

http://bergall.org/temp/venture/1stcarbs3.jpg

 

I don't think you COULD get in a big enough crash to even GET to them...

BUT... If someone was to try and buff them on a grinding wheel... you might have to add a dab of silicone when you broke through... I guess after the first one they weren't convinced?

[Neil86]

Perhaps they mistakenly thought they could adjust the height of the needle by moving the screw in top of the diaphragm?

As for the running lights...the front should work regardless of the CMS....the tail light would be affected by the CMS.....going by your voltage readings, yes something is wrong in the CMS....hopefully solder crack.

[Tupperj]

Are you talking about those big aluminum carb diaphragm covers...

(Pay no attention to arrowed items...)

http://bergall.org/temp/venture/1stcarbs3.jpg

 

I don't think you COULD get in a big enough crash to even GET to them...

BUT... If someone was to try and buff them on a grinding wheel... you might have to add a dab of silicone when you broke through... I guess after the first one they weren't convinced?

 

Yep, those are the ones! I agree about crash damage, would REALLY tear up the bike. I'm thinking PO tinkering. This is the same bike with electrical damage that someone attempted to repair with wire nuts. And bypassing the fuse block.

 

People do the darnedest things to bikes.

 

Thanks!

Paul

[Tupperj]

Perhaps they mistakenly thought they could adjust the height of the needle by moving the screw in top of the diaphragm?

As for the running lights...the front should work regardless of the CMS....the tail light would be affected by the CMS.....going by your voltage readings, yes something is wrong in the CMS....hopefully solder crack.

 

Thanks Neil. Really don't understand the carb thing. Glad I have replacements.

 

I'm embarrassed to admit that I don't know for sure if the front running lights come on. Target fixation I guess. Guess I'll have to pull the CMS. And I just got the fairing pieces all buttoned up! Teach me to jump the gun.

 

Take care.

 

Paul