BS38 Carburetor Issues

There is a crossover hose just below where the fuel lines connect. This allows either line to feed both carbs if need be, like if you ran one side of the tank dry.

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Understanding the "cause and effect" of the adjustments you'll be doing on the timing and points can simplify the task. Here's an explanation .....

http://xs650temp.proboards.com/thread/7984
 
That's what I thought. My hope is that after getting new floats it should solve the too rich problem. Thank you for the info on timing. I really had no idea how to go about it lol. I've had this bike for almost a year now and have never ridden it for more than 20 minutes. It is my first bike though so I didn't know what I was getting into when I bought it. The owner took advantage of me by rigging it up to run for two minutes. Rode it home and before I got to the house the headlight stopped working and the bike cut out. I've been on this forum ever since lol.

Oh well live and learn lol. I love the bike and with this forums help I am closer than ever to having a reliable ride :) Thanks to all who posted on this thread for helping a kid with no knowledge!
 
So I have a problem of black carbon fouled plugs. They both get carbon fould very quickly almost as soon as the bike is running?... I put in brand new plugs today after installing new floats and within a couple seconds of running I pulled them and they ere all black.
 
I went back through this thread, and several red flags popped up. Let's take a step back and review.

We need to absolutely confirm the year set of your carbs, and ensure that there hasn't been any funny business going on there. Like wrong float bowls on different year carb bodies, wrong pilot jet type on different bowls, ...etc. Would need good, crisp, clear pics of:

Carb bodies, from top, sides, inside
Float bowls, from the inside without gaskets in the way
Pilot jets (all of them), to determine if atomizer holes are properly drilled and if jet orifice is on top or bottom.

I believe that the carbs do have some function to share over flow of fuel.

No. They share fuel delivery. Once the fuel goes past the float valve into the float bowl, it stays there, doesn't transfer over to the other bowl.

My choke plunger is in the right position so I think its ok.

The wheezing sound in your video, the fluttering of the slide diaphram, the excess richness. These are indicators that the choke plunger(s) may not be sealing properly. Won't know for sure unless they're disassembled, cleaned, and checked. Same for the enrichner crossover, if it exists.

Hopefully a new set of floats will solve my rich problem then it will be on to figuring out the timing. I have read the instructions on ignition timing and have to say it seems complicated to someone like me that has never done it hoping to find a video that will show I first hand.

The ignition timing should be set first before trying to solve carb problems.

That's what I thought. My hope is that after getting new floats it should solve the too rich problem.

We all wish that our problems are solved by a single fault. Sorry, doesn't always go that way.

The owner took advantage of me by rigging it up to run for two minutes.

This requires the talents of a sadistic genius. It would've been much easier for him to fix it, if he could.
Step away from the paranoia. You CAN get thru this.

So I have a problem of black carbon fouled plugs. They both get carbon fould very quickly almost as soon as the bike is running?... I put in brand new plugs today after installing new floats and within a couple seconds of running I pulled them and they ere all black.

Just for fun, on your next ride, turn-off the petcocks before taking off. Ride around for about 30 seconds. If it runs better, and the plugs don't load-up, the float heights may be off.
 
I have dismantled the bike. I took the headers off and realized that the inside of my engine had carbon and oil throughout and very built up. I also am sure I have a leaking valve on the left side cylinder I need to address.

My hopes are too eliminate some of my carb problems by going with a side mounted single bs38. I've always loved the look and thought it couldn't really be more than finding the correct jet sizes.

What does this mod do for the bike?

Why do the old race teams have them?

Is there a lag in the throttle response because the fuel has further to go to get to the engine?

Thanks in advance for your responses.
 
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