Topic: 1975 400F hard start

[tory b]

    I have finished my 400F and have been enjoying riding it.But it seems to start very hard.
I have been trying to give it at least a quick ride everyday to see if it gets better,but no luck.

To start the bike you hit the starter button or kick starter and it will sputter for a second.If you touch the throttle it dies immediately.So you just keep cranking,let sputter,crank,let sputter,crank,let sputter....until it stays idling. NEVER touching the throttle.I have tried playing with the choke,but it doesn't like that,and if you try to give it a little throttle it does not like that at all.
  Once its idling for a second or two it runs perfect and starts instantly all day.
While I was reviving the bike,the carbs where stuck.I completly dismantled them and cleaned them with an ultrasonic cleaner and installed new kits.Then balanced/synced them once installed on the bike.

Any suggestions?

[kslrr]

What is the color of the spark plugs? 

Do you start it with choke On or OFF?

It still sounds like a carb issue due to it' being so sensitive to throttle and choke movement.

[tomkimberly]

I too think it's with the choke, are you sure you know how it functions?

Tom

PS, Hi Dan!

[tory b]

Plugs are nice and gray,runs perfect once started.
Starts with out choke,but I have tried it in other positions.And yes,I know how to use it.Rather straight forword,marked clearly and I got a good idea of its positions as I had put it togethor.

[tomkimberly]

How did you clean the carb? Did you dis-assemble or just removed the bowls and sprayed?

When you use the choke, do the butterfly's close fully?

Tom

[kslrr]

If it starts without the choke, that could indicate a rich idle mixture, though it runs good once warmed up.  Is the throttle responce crisp and smooth once warmed?

PS, Hey Tom!

[iron_worker]

If it starts with no choke I would also say it is rich. When it's dead cold it should need some choke.

I would think it would become obvious once it's warm that it's way too rich though ...? Or maybe its only your idle circuit that is rich?

What are you mixture screws set at?

IW

[tory b]

How did you clean the carb? Did you dis-assemble or just removed the bowls and sprayed?

When you use the choke, do the butterfly's close fully?

Tom

As I stated in my first post,I completely disassembled the carbs,cleaned them in an ultrasonic cleaner and installed new carb kits.

Yes the choke is functioning completely and properly,though as others have also said,I doubt the choke is the issue as it requires no choke or throttle to start.Just Patience.

IW 
The mixture screws are set at 1 1/2 turns out.Should I try to turn them in a bit?And would that require re syncing?
I appear to be getting about 35 mpg,although I only expected 40.

KSLRR
  The bike seems to run great once started the first time daily,with the exception of a small sputter at low RPM shifts I noticed periodically today.Mid to high rev shifts its perfect.