mikuni carb trouble

Bike has been sitting for 6 months. I took apart the carb and cleaned it out with carb cleaner. Put it back together. the bike starts first kick with the choke on. however, when I take the choke off the bike dies. Also, if I give it gas with the choke off it bogs and then dies. What could have happened? I didn't take out the float needle or the idle or adjuster screw - only took the slide out and the float bowl off. thanks

rgla said:

Bike has been sitting for 6 months. I took apart the carb and cleaned it out with carb cleaner. Put it back together. the bike starts first kick with the choke on. however, when I take the choke off the bike dies. Also, if I give it gas with the choke off it bogs and then dies. What could have happened? I didn't take out the float needle or the idle or adjuster screw - only took the slide out and the float bowl off. thanks

Click to expand...

Sounds like the pilot circuit is plugged

rgla said:

Bike has been sitting for 6 months. I took apart the carb and cleaned it out with carb cleaner. Put it back together. the bike starts first kick with the choke on. however, when I take the choke off the bike dies. Also, if I give it gas with the choke off it bogs and then dies. What could have happened? I didn't take out the float needle or the idle or adjuster screw - only took the slide out and the float bowl off. thanks

Click to expand...

yes could be the pilot jet is still plugged - do you give the bike time to warm up - it will need it? and is the gas in the tank 6 months old too? I'd replace the gas 1st thing. 2nd I'd remove the carb and give it a good spray in all the jet orifices again (don't just drop the float bowl and spray - ensure you can blow air through them) and then when you put it back on ensure the mounting camps etc are nice and tight (only running on choke can be caused by an air leak too!)
good luck..
m

If I run my 750 for too long on the choke it buggers up the spark plugs.
I usualy start mine on the choke then turn up the throttle stop screw to get the bike running faster, then turn off the choke.
It does take mine quite a while to warm up. I agree about puting in new fuel as the stuff does go off within 6 months.
Best of Luck with it.
Cheers Don

I started with fresh gas. I usually have the choke on for a minute or so and then click it off leaving the bike idling perfect. I'll take it apart again but carb cleaner did spray out the otherwise of the jets. Might be my new fuel filter config. I'll try running fuel straight to the carb no filter

Make sure you pull the jets out, especially the pilot jet. Shoot cleaner and air from all side of the orifaces. Then do the same with the jets, especially the pilot jet.
Once back together, I would re astablish your setting.
1. Turn air screw in all the way and then out 2 turns.
2. Fire up the bike and turn the IDLE screw to get it to run with out the choke.
3. Get it a little warm for a minute or so.
4. Turn the AIR screw( in or out) so that the idle will rise.
5. Adjust the IDLE screw to bring it down just berfore stall.
6. Repeat with the AIR screw and alternate with the IDLE screw.
The rest will be a fine adjustments with the AIR screw to attain a good initial throttle responce. Then re adjust the IDLE screw to suit.
I think the best thing about the Mikunu is the IDLE screw.

Now try to imagine doing all this with 2 units to sync.