some poping at about 4000 rpm

[greentreena]

It seems around 4000 rpm there is some poping out of the exhaust. I pulled to spark plugs and they look great. I'm not sure if the plug wires are failing at the higher RPM? The pipe is a yoshi slip on, otherwise a stock bike.

It was cold today, would that have played a role? about 7 degrees C (or 44 F). I don't recall it doing this on other cold rides.

If this was my car I would advance the timing a bit however, it doesn't seem like I can do that on the bike.

Any thoughts or suggestions? Thanks

[eddie_93katana]

It seems around 4000 rpm there is some poping out of the exhaust. I pulled to spark plugs and they look great. I'm not sure if the plug wires are failing at the higher RPM? The pipe is a yoshi slip on, otherwise a stock bike.

It was cold today, would that have played a role? about 7 degrees C (or 44 F). I don't recall it doing this on other cold rides.

If this was my car I would advance the timing a bit however, it doesn't seem like I can do that on the bike.

Any thoughts or suggestions? Thanks

Might need to be rejetted for the yosh exhaust?

[Kreylyn]

Poping in the exhaust generally means lean fuel mix. If it's specific to an rpm range, I would generally narrow down the cause by using the guide provided by Factory Pro for the tuning the carbs to see the most likely components of your carbs to look at for tune/cleaning.

Krey

[greentreena]

what is confusing is the plugs: they show a perfect mixure. My first thought carb problem to.

[ratgti]

kreys the man here . hope you get it sorted out

[greentreena]

So I double checked the carb sync, it was perfect however I thought perhaps it is too perfect for the bike to run properly. So I do a re-adjustment with a focus on adding more fuel and having a less than perfect sync. The end result is there is a lot less popping and the power still feels good. So this further confirms my suspisions that next winter I'll be over hauling the carbs. The sync is still good so I'll ride it for a bit and then double check the plugs to makes sure they still look good.

[TRPUT]

No such thing as a carb synch being too perfect.

How did you add more fuel? Just cranking the mixture screws isn't targeting that 4000RPM area. Depending on throttle position it is more likely to be needle / jet related or perhaps float levels????

Krey's reference to the carb tuning procedure will help you narrow it right down.

[Scout]

Had the same popping the instant I put an aftermarket exhaust on my Kat, as well as with my carb'd R6. It's the nature of not re-jetting/or doing it improperly. Wont hurt anything, to have popping. Pro bikes pop on decel all the time, and they know best, right?

[Kreylyn]

Wont hurt anything, to have popping. Pro bikes pop on decel all the time, and they know best, right?

You mean the Track Racers... who have an entire team of people that disassemble, rebuild, replace, and swap motors on a regular basis between each race day?

Those guys?

I'm not so sure they are worried about longevity of the parts they use and set the bikes up for much further than just the single race day.



Krey

[scottynoface]

You mean the Track Racers... who have an entire team of people that disassemble, rebuild, replace, and swap motors on a regular basis between each race day?

Those guys?

I'm not so sure they are worried about longevity of the parts they use and set the bikes up for much further than just the single race day.



Krey

[Scout]

You're right, Krey. But, 36,000 odd miles on my 2006 (all my miles), and no issues. I'm not saying it's optimal, but it certainly isn't damaging, either.