TOPIC:

Some more progress and questions. Spent most part of the day yesterday getting hardware ready for plating. All bead blasted. Photo shows just hardware for head. There is much more..

Question on carb. What is this brass tube? Should there be hole on tip(red arrow)? And those holes on a bottom, drilled across, where do they go? Want to make sure there is no blockages.
Carbs were cleaned in ultrasonic cleaner with simple green solution. Not that they look very nice. Covers came out much better.

Any advice on cleaning small parts? Jets, floats, etc? 

 

The brass tube is the fuel pickup for the choke.
The hole in the bottom should be clear and also the ones at the base.

wrote:

The brass tube is the fuel pickup for the choke.
The hole in the bottom should be clear and also the ones at the base.

Any advice on cleaning bottom hole? I have jet cleaning tool but even smallest won't fit.

I use individual strands out of stranded electric wire. Different gauge wire will have different individual size strands. You can buy a few different short lengths from your local auto part. The big box home goods stores will sell it by the foot. 

wrote:

I use individual strands out of stranded electric wire. Different gauge wire will have different individual size strands. You can buy a few different short lengths from your local auto part. The big box home goods stores will sell it by the foot. 

Have plenty of this stuff.. But this hole is so small. Not sure I can poke it through with such tiny wire. 

If you blow compressed air into the choke cavity you should be able to feel air coming out the hole in the  brass tube.  If you don't have a compressor you can buy a can of compressed air at a computer shop.

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If you blow compressed air into the choke cavity you should be able to feel air coming out the hole in the  brass tube.  If you don't have a compressor you can buy a can of compressed air at a computer shop.

I do have plenty of shop air. And no, don't feel it. I feel air coming from those holes on sides, but not hole with arrow. I will need to see if all carbs the same.

I use a pen light. Or a gun bore light. Shine it thru the side holes, look into the end hole. You can see light if it’s clear. You can heat the tube carefully to soften up any varnish build up. My concern being if you just poke A hole Thur a glob of varnish now then later when gas is in the pipe does it have the potential to soften up and close up the hole. I’d like to find a process that will completely remove all varnish and debris from inside that pipe.

I have a feeling I had that exact thing happened. I rebuilt a set of carbs and put them on my bike. Choke enrichment circuit worked perfect for about three weeks possibly a little more. One day the choke had no affect on the system other than needing it to start the bike. Once the bike was started there was no effect on rpm indifferent to any position of the choke enrichment lever. I can’t keep the cold bike running with the choke.

There is also a jet in the bottom of the bowl where that pipe lives once the bowl is affixed. I was very meticulous cleaning both the pipe and that jet and using a pen light to make sure both passageways were completely clear. My thought is some varnish or goop has softened up inside that pipe and closed up the hole in the choke enrichment circuit.

wrote:

wrote:

The brass tube is the fuel pickup for the choke.
The hole in the bottom should be clear and also the ones at the base.

Any advice on cleaning bottom hole? I have jet cleaning tool but even smallest won't fit.

I used old guitar strings, the thinner ones on the bottom of the guitar neck work well....

Carb spray is good for checking those passages.  Put the spray straw in the tiny hole in the bottom of the choke cavity and shoot.  You should see it come out the brass tube at both the bottom and from the cross drilled holes.  Put the straw in the hole in the float bowl and make sure that passage is open too.  Same thing for all the pilot passages and holes in the inlet side of the carb.  Spray and watch where the spray comes out.  Using compressed air is good for cleaning out he passages too.

There is some play in this linkage (riveted pieces wobble). Does it affect anything? Should I try and press those rivets to remove play?



 

wrote:

There is some play in this linkage (riveted pieces wobble). Does it affect anything? Should I try and press those rivets to remove play?




 

Don't tighten those rivets.
They are meant to be like that.