No start unless choke completely off - DR600 1989

[carlitox33]

Hello,

This is my first post after my intro.

My 1989 DR600, will not start from cold, even if you pulll the choke plunger. I have dismantled and cleaned the carb, set up the decompression cables, and everything seems normal.

HOWEVER!!!!

If you completely take off the choke plunger (if you unscrew it and take it away, leaving the hole), the bike will start at the first kick with no problem! After that, if you put back the plunger, it will idle fine, and run great.

Just for reference, this is the plunger:



Any ideas of what I can do? Of course, I can just take the plunger off everytime (only on cold - on warm engine it starts great)... but it is not so "elegant".

Regards.

Carlos

[hiha]

That's great. I have no idea, which makes any sense.
You can think about the funktion of the different bores and channels, and what they [should]do, if you pull/remove the plunger.

Edit just had an idea: The Plunger is not the original one. There are plungers for other Mikunis which look equal, but are slightly different.

Cheers,
Hans

[Max krachmach]

try to kick 10 times without ignition and with deko pulled. after that it could work. Propably there is to much fuel somewhere

[carlitox33]

Hans, thanks for the reply. The picture I added is not the original plunger (it´s from a TU250), but I have the original plunger (have actually tried 4) and nothing changes.

I have actually changed the carburettor to a different one, and still the same thing!

In regards to the kicks, I´ve tried the "brute force" approach; of kicking it away... but will not work.

This is really strange. As I understand, taking the plunger off puts a lot of air into the system. Why would it work so well?

[carlitox33]

The original plunger is this, and is the one I use:

[franz muc]

your carburetor is VM38 ss?

[Max krachmach]

The original plunger is this, and is the one I use:

he is using one with an longer grip

[carlitox33]

your carburetor is VM38 ss?

Yes. It´s a standard flatslide MikuniVM38SS. The original one. It came with the bike.

[franz muc]

is your idle mixture screw in right position?
1 and 1/2 out or 1 and 3/4?

is at this screw everything in its place?

[carlitox33]

is your idle mixture screw in right position?
1 and 1/2 out or 1 and 3/4?

is at this screw everything in its place?

It is actually 2 turns away from full stop.