Popping on deceleration

[Redhot]

Generally when I start bike after a couple of weeks, it blows a little blue smoke, even shutting choke off, which goes away after a few minutes. Not sure if this is rich or oil from worn rings. However, today, when I blipped throttle, it popped through exhaust. Not a bang backfire, just popping, which I'm sure I've not heard before. When riding, the same happens on deceleration. When I got home an hour later, it was hardly noticeable. What might be causing this ? I figure any vacuum leaks or blocked pilot jets wouldn't go away after an hour ?

[ct1500]

The popping on deceleration is usually caused by an excessive amount of air being pumped into the exhaust (an emission requirement thing). First off check for an exhaust system that might be starting to rot out. Next thing to check is the AIR injection system which requires air filter removal to monitor intake hose at bottom right front of box. When throttle gets rolled off the sucking sound must momentarily cease if not it will cause the popping sound and further diagnosis needs to be done on the system. This is all presumed that the MC is emission equipped and can be confirmed by the presence of the AIR pipes into the cylinder heads. If all OK there my next check point would be the carb and Air Jet Controllers.

[Redhot]

I'll check that, thanks, but why after a reasonable 1 hour ride doesn't pop ? (It still pops after 15mins, on a warm day). If there was exhaust rot, it would pop the same after a journey ? What would change (heat ?) in that time to lessen the popping ? That's what I find odd. I've just discovered the blue smoke is a bit oil residue after keeping on side stand, doesn't do it after leaving on centre stand, that's a relief.

[ct1500]

Your MC is experiencing a problem and for me to speculate why a particular component might be misbehaving at times is premature before some very simple checks are done. The 1500 is just way too complex for easy answers most of the time.

[joeincalif]

The smoke on start up is normal, especially if you park it on the side stand, Oil seems past the rings and will burn off on start up,

[Redhot]

Your MC is experiencing a problem and for me to speculate why a particular component might be misbehaving at times is premature before some very simple checks are done. The 1500 is just way too complex for easy answers most of the time.

Yup ! But you've given me some great starting points, so thanks