Carb Setup suggestions

[dkaiser]

Hello all,

 

Working through my "87 project, coming along well.

 

I got a set of rebuilt carbs for a deal and put them on, been reading all of the threads on adjusting, very interesting indeed.

 

So, I have it running fairly well, but to do it I have the idle mixture screws out about 4 or five turns, I know that is not right, but for now that is where they are.

 

I worked through adjusting the butterflys according to one of the threads, and now it will start pretty well, and doesn't crack and pop so badly on throttling down.

 

Here is what I am noticing now though --

 

It was smoking when I was running it tonight (All of this is just running on the center stand) so I took the flashlight to see what and why. Well there is gas dripping out of at least one of the hoses that come out of the top of the carbs, some kind of overflow for the bowl I'm guessing. So I shut her down right now. Don't need to burn my bike down, right.

 

So any insight, what does this mean and what should I do about it?

 

Of course I am working toward getting them syncronized, but for now this is where I am

 

Thanks for all of your help

 

David

[Guest ssparks905]

David,

The gas dripping from the overflow line would indicate that the float valve in that carb isn't closing. This could be debris preventing closure or a leaky float.

 

Sadly, you may have to take the carb apart to correct the problem. Several great articles in the forums about cleaning and repairing the carbs. While you have the carbs apart, check the air bypass diaphragms (little diaphragms on the side of the carbs). Mine were stiff as cardboard! Ordered some off eBay and now the idle works much better with adjust screws set at the recommended two turns.

[Denden]

If you have to turn the pilot screws out THAT far, it's a good bet that the jets are clogged. Also, gum and varnish built up in the float bowl will make the floats stick, and that's probably why the gas is coming out the overflow hose. It sounds like the bike has been sitting for a long time with gas in the carbs, and the gas has turned to varnish.

You should get some Seafoam, and pour the whole can in the tank. run the engine until you are sure it has gotten to the carbs, then shut it off and let it sit overnight. Run it again the next day, ride it if you can. If you can't ride it, at least let it warm up real good, rev it (quickly) a lot, then let it sit overnight again. I can't say this will definitely get your carbs clean, but it is a good start. If Seafoam doesn't work right away, it might work after a while.

But the best thing to do, if you want to be sure it's gonna run right, is to pull the carbs, separate them, and clean them.

And by all means get a carb sync tool. This V4 HAS TO BE SYNCED TO RUN RIGHT.

[dkaiser]

Great suggestions, I now have a plan of action for tomorrow.

 

Thanks

 

Seb

[Bob K.]

While you have the carbs apart, check the air bypass diaphragms (little diaphragms on the side of the carbs). Mine were stiff as cardboard! Ordered some off eBay and now the idle works much better with adjust screws set at the recommended two turns.

What are the "air bypass diaphragms" you mention? Do you mean something associated with either the starter plunger or the coasting enrichment diaphragm (under the small, round cover)? I just finished disassembling and cleaning the carbs on my '93 and want to make sure I didn't miss something.

Edited August 10, 2018 by Bob K.

[Marcarl]

What are the "air bypass diaphragms" you mention? Do you mean something associated with either the starter plunger or the coasting enrichment diaphragm (under the small, round cover)? I just finished disassembling an cleaning the carbs on my '93 and want to make sure I didn't miss something.

 

These would be the diaphragms for the sliders. Cover for them is on the outside of the carb, square, held in place with 4 screws.

[Prairiehammer]

What are the "air bypass diaphragms" you mention? Do you mean something associated with either the starter plunger or the coasting enrichment diaphragm (under the small, round cover)? I just finished disassembling an cleaning the carbs on my '93 and want to make sure I didn't miss something.

 

check the air bypass diaphragms (little diaphragms on the side of the carbs). Mine were stiff as cardboard!

 

The "air bypass diaphragms" (I've never heard the coasting enrichment diaphragm called that before) that ssparks905 referred to are in fact, the coasting enrichment diaphragms aka air cutoff valve. If you did not disassemble and examine the diaphragms for tears, swelling, cracking or stiffness when you "cleaned" the carbs, you did not get the entire carb cleaned or properly rebuilt (if rebuilding was your intention).

 

Air Cut-off how it works.docx

[Bob K.]

The "air bypass diaphragms" (I've never heard the coasting enrichment diaphragm called that before) that ssparks905 referred to are in fact, the coasting enrichment diaphragms aka air cutoff valve.

Good! I did indeed inspect and clean the coasting enrichment circuit.