Need to check out a slight misfire when cold

[ianmck]

Had a similar problem on my 400, which had not been run for about 5 yrs, followed some of the suggestion above, decided to remove the carbs, cleaned the float bowls etc. found two of the pilot jets clogged, soaked them in injector cleaner, gently poked thin wire into them and blew them through with compressed air. re fitted all parts and re fitted the carbs. Started up and ran perfectly.
So thank you for above tips.
Ian Mck

[Alexrayz]

As has been suggested, it appears it is the idle jet.  With the engine at idle, there was no reaction when turning the idle screw on that carb from totally closed to 2+ turns open.  The other three immediately affected the idle rpm/smoothness.   When I overhauled/synched the carbs last year, all of the mixture screws affected the idle as they were adjusted in/out. 

I don't think there is a satisfactory way to clean the passage with the carbs on the bike but please tell me if I'm wrong about that!!

Any news on your situation Mike?


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[Mikep328]

No - I didn't manage to get back to the garage/bike yet - some things came up.  Hoping to do so tomorrow.  I'm going to blast some cleaner in via the air screw hole with a large syringe.  If that does nothing I'll likely let it go as is for a while since the bike runs great on the road and I'd rather ride it than pull the carbs!    I'll certainly post whatever I find!

[McCabe-Thiele (Ted)]

It might be worth putting some injector cleaner in your petrol - it could clear with normal use.

[Mikep328]

Finally got around to checking this - pulled the airscrew, shot some carb cleaner in.  Reinstalled air screw to same turns, started bike - #3 pipe heated up immediately just like the others!   

[McCabe-Thiele (Ted)]

Nice one.

[Athame57]

I bet you had fun putting the carbs back in!  Glad you have it sorted.

[Mikep328]

Fortunately I didn't have to remove the carbs this time.  I pulled the #3 airscrew and shot the carb cleaner in with a plastic syringe/short piece of stiff tubing that I tapered at the end.  I managed to get a good seal with the taper in the airscrew fitting threads so there was a good bit of pressure with the carb cleaner so it cleared whatever may have been causing an obstruction.

[Alexrayz]

Fortunately I didn't have to remove the carbs this time.  I pulled the #3 airscrew and shot the carb cleaner in with a plastic syringe/short piece of stiff tubing that I tapered at the end.  I managed to get a good seal with the taper in the airscrew fitting threads so there was a good bit of pressure with the carb cleaner so it cleared whatever may have been causing an obstruction.

Marvellous!

Congratulations Mike


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