Carb Pipes

Hi,
I'm new to the Z scene, use to be a Yamaha man. I've just re-built a Z500 1981 (European Model) and I'm very pleased with the bike, but I'm not sure what the 2 pipes that link the carbs do. The carbs are TK sliders and the pipe links carbs 1&2 together and 3&4 so there are x2 pipes that look like vents. I've read through the clymer & Haynes manual and they only refer to theses for the venting system which Isn't on my bike. Do I leave them open and feed them to the top of the air box or do I plug them up? The bike runs uneven at present but I've only started to tune it in, so could have some more questions.

If anyone can advise me that would be great.

Cheers
Colin (converted to Kawasaki's)

gravityoutlaw wrote:

Hi,
I'm new to the Z scene, use to be a Yamaha man. I've just re-built a Z500 1981 (European Model) and I'm very pleased with the bike, but I'm not sure what the 2 pipes that link the carbs do. The carbs are TK sliders and the pipe links carbs 1&2 together and 3&4 so there are x2 pipes that look like vents. I've read through the clymer & Haynes manual and they only refer to theses for the venting system which Isn't on my bike. Do I leave them open and feed them to the top of the air box or do I plug them up? The bike runs uneven at present but I've only started to tune it in, so could have some more questions.

If anyone can advise me that would be great.

Cheers
Colin (converted to Kawasaki's)

Hello, Colin, and WELCOME to KZR!
We'reglad you're here!

Maybe the photo in link or next post will help, if the carbs are similar (manual throttle slide), and not CV (constant vacuum) style.

Some carbs have dual fuel inlet tees (to accomodate dual fuel lines). Many don't have the separate 5th vacuum nipple for vacuum operated petcock. And many don't have the accelerator pump as shown on #2 carb at bottom of floatbowl.

All vacuum nipples should be capped in normal operation, except one nipple for a hose to vacuum petcock where bike is fitted with vacuum petcock.

The 4 vacuum nipples are used for syncing the carbs.

The two vent hoses exit to open air and vent all four floatbowls. I prefer routing the vent hoses to underneath the seat. But some prefer routing them between the frame and swingarm to exit underneath the bike.

Good Luck!

[Click on image to enhance view]

[Click on image to enhance view]

Cheers Bro,

That's most help full, I had a feeling they where vents and you've confirmed with the picture.

I had to sell all my previous toys cause of new baby and I brought a Z500 & Z550 that was going to scrap and decided to build myself a bike to go to work on. But I'm highly delighted with the finished Z500 bike. I've noticed that there are very few Z500's for sale and parts tricky to get hold of, are these quite rare now in good condition?

Cheers
Colin

GravityOutlaw:

Check the excellent diagrams that Patton has offered to determine what is what.

It sounds to me like the two hoses you are refering to - are the VENT lines for the fuel bowels. If I am correct, and in an ideal situation,the ends of these two hoses should come together into another "T" fitting. Then the third part of the "T" should have a hose that leads down through the frame near the front of the swing arm and opens to the atmosphere. That way - If the bike is ever laid down - fuel will spill out through this hose and not over the hot engine, increasing the chances of a fire.

When I first got my bike, the previous owner had replaced these two hoses with one new hose that connected the two sides. This did not allow the fuel bowls to fill since pressure would be built up, and the carbs wouldn't fill enough to run properly. The bad news is - that it took me weeks with Wiregeorges advice - to figure out what was wrong. The good news (for me) - is that this is why the previous owner couldn't get the bike running and decided to sell. Good luck and welcome to the great KZR site.