Carbs and Fuel, or is it Electrical?

[Andy_UK]

Hello
I live in the UK and the XZ550 is NOT a popular bike. For many reasons I guess. Anyway, seems like the guys across the pond in the US have got this vision thing licked!
I have an issue.
My bike is a bitch to start. Even with a new, fully charged battery. But once started and on Choke it seems OK. However, once off choke and riding all is not well. When you open the throttle the bike dips in its revs, rather than increase immediately. After a couple of seconds it picks up and off you go. Again, if I switch it off after being warmed up, I cannot start it again! I have to wait for it to be coldish before successfully starting it.

What do you techie boys think? Is it a carb problem? or an electrical one?

Would appreciate some quality feed back. Lastly does anyone have Dave Sulecki's e-mail address. His restoration project is awesome and it has fired me up to get on with mine next winter.

[yamy]

 :D

Andy - Sent you an E-mail, you can contact me directly. Glad you like the Vis, I spent many, many hours on it. Lots of fabrication and machining, but it was worth it!

Glad to help out with any advice I can. Also, these guy's that visit the site are great for help.

- Dave S.

[Cdnlouie]

I think your choke response is the best indicator that you have a fuel problem. ?Electrical rarely half-works, it either works well or not.

A preliminary thought: Does your accelerator pump shoot fuel into the throttle body?  Look into the carbs with the air cleaner off and turn throttle.  It operates off the throttle and squirks some fuel into the throttle body whenever you turn it, running or to start.  This helps with getting the vision going until the main jets start delivering fuel.

Is the bike new to you or have you had it for a while? ?A bit of history on the bike and what you have maintained or not helps anyone who is trying to point you in the right direction. ?Have you read some of the posts especially Lucky's site with the 10 most common vision problems?

Louie ? :-/

[Andy_UK]

 :)
Thanks so far, I was looking more at the fuel side of life. I think it might be a mixture issue. The guy I bought it from suggested that the main jets needed changing! So I will investigate further.

[Cdnlouie]

One of the first things is to know what you've got on your bike.  Check the air jets and the main jets for what sizes they are.  Air on the top and mains are behind the 10mm nut on the left side of the motorcyle carb bowls.  Check a Haynes manual for a general description of what is what here.  Once you know what you are running post them just to be certain your working with workable hardware and then make sure the carbs are clean, followed by a sychronization, proper fuel mixture screw settings and you should be in better shape.

[Lucky]

Actually, I think if it allways needs choke to run that meens it's running lean, i'd check the YICS for a leak (see my site) or other vacume leak, such as the petcock diaphram, or a split hose.
--Lucky