650r starting problem

when cold it starts 1st kick, but idles rough and stalls. I then restart it and it idles rough and stalls. I do this several times and then eventually after 5 or 6 times, it starts and the idle is fine and i wait till it warms up and i am gone. no running issues once warmed up. My starting procedure is as follows:

1) 1/2 choke (full choke it wont start)

2) pull decompression in and kick through maybe 5 times

3) let decompression out and kick through until hits the hard spot

4) pull decompression back in and push just past hard spot

5) bring it back up and kick...and brrrpp it starts

but not for long...rough idle sounds like it choking out and stalls. If i give it any throttle before its ready it will immediate stall. so i start over and it fires up and stalls. after a few time all of a sudden it fires up and the idle is perfect and it happily warms up.

Do I need to do the flooded start procedure if it hasnt started in a week or so clear the bowl out? will that help maybe?

from what i am reading is the jetting maybe off and its flooding? or is it to lean?

I have experimented with choke positions and it likes less rather than more.

the bike has a stock carb, it was jetted and uncorked by previous owner. since i got it, I have just checked valves, changed oil and spark plug.

thanks alot guys!

when cold it starts 1st kick, but idles rough and stalls. I then restart it and it idles rough and stalls. I do this several times and then eventually after 5 or 6 times, it starts and the idle is fine and i wait till it warms up and i am gone. no running issues once warmed up. My starting procedure is as follows:

1) 1/2 choke (full choke it wont start)

2) pull decompression in and kick through maybe 5 times

3) let decompression out and kick through until hits the hard spot

4) pull decompression back in and push just past hard spot

5) bring it back up and kick...and brrrpp it starts

but not for long...rough idle sounds like it choking out and stalls. If i give it any throttle before its ready it will immediate stall. so i start over and it fires up and stalls. after a few time all of a sudden it fires up and the idle is perfect and it happily warms up.

Do I need to do the flooded start procedure if it hasnt started in a week or so clear the bowl out? will that help maybe?

from what i am reading is the jetting maybe off and its flooding? or is it to lean?

I have experimented with choke positions and it likes less rather than more.

the bike has a stock carb, it was jetted and uncorked by previous owner. since i got it, I have just checked valves, changed oil and spark plug.

thanks alot guys!

Before i got Mikuni TM40 pumper my stock carb was a bit of a pain but once i got used to it, it wasnt too bad, usually i would give it a kick or two until it coughed and died with full choke, then move to half choke and it would usually start straight away and idle normally then move to no choke before i take off.

I normally could never get away with half choke as it wouldn't even fire as the cold blooded beast needed full choke.

Good Luck

Matt.

Ya my xt always would take full choke, which is why I don't understand why the xr is definitely no go with full choke. I have read others say that full choke floods and they can only use half choke. Am I interpreting this correctly? I am going to try a suggestion I read to start with hand on the break as to not mistakenly feather the throttle. My starting routine is good because it fires right away, but just won't hold the idle. I am going presume idle is set ok because once warm idle is beautiful. I don't know? Thanks for the feedback Matt.

What about idle speed ? Spark plug ? What about putting the choke lever between off and half ? Does your fuel screw on the side make a difference when it is adjusted ? I have been round and round with the bike I just bought . But I have it running and stating as close to perfect as I would think possible.

if I turn the fuel screw counterclockwise it will be leaner at cold idle and not be apt to flood when starting? is this the idea? will it effect the warm idle which has been great or worse effect running? thanks

Yes it will be leaner. I was just wondering if it made a difference when adjusted cause if it doesnt I think that signals trash in the pilot circuit. Is the carb clean ?

Edited by jmz

the previous owners service records showed he had the carb cleaned last may. I have not taken it out so i dont know. How often should it be done? he said he did not put stabil in it over the winter. I started it with the filter off and air box open. it wanted more choke, but still stalled. I did the flooded starting routine and started good but then the idle dropped back down and bogged out to stall. I am wondering if the idle is set to low? when it is bogging out to stall its idling about 550 rms, but when it catchs a good idle warms up it idles around 650 rms. Is this too low? thanks

ya so i opened my manual. :smirk: idle speed is recommended at 1400. I dont know if my vapor tach is all that accurate cuz my read out is wayyy below that even when it seems to be idling well. i dont know... guess i'll try and turn it up and see what happens?

Turn a little at a time while your trying to crank it. That is what I did.

turning idle up..clockwise or counterclockwise?

Counter. I would say clean the carb if in doubt.Very easy. My tank filter was shot.

ya i just needed to turn the idle speed up a bit. problem solved. thanks for talking me threw that simple fix.

ya i just needed to turn the idle speed up a bit. problem solved. thanks for talking me threw that simple fix.

I was going to say turn the idle up, but you got it figured out.

You turn it clockwise (righty-tighty) to increase idle, but since it is upside-down it is towards the back of the bike, or counter-clockwise just depending on how you look at it.

I had the same problem until I removed the choke flap. Now full choke almost isn't rich enough, but it lights quick and will idle better. I don't have to turn the idle up and down anymore.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now