Rough idle and popping in exhaust

[jowens]

I have had a 2009 RSV for alittle over a year. The bike has always had a rough idle but you used to be able to start it without the choke on a summer day for the first time and it would idle real low til it warmed up. Now when it was first started even on a summer day you have to choke it for the 1st minute or so or it will not run. The idle has gotten worse in the last month or so and now I notice a slight popping coming from the exhaust on the right side. I have ran plenty of sea foam through it and it did not help. I can pull the right rear spark plug wire and you only notice a slight difference and the popping all but disappears until I reconnect the spark plug wire. I have put new iridium plugs in it and switched the 2 ignition coils in the back which didn't make any difference. it smells like it is burning rich. Have a carburetor sync gage on order so that will be next. Have not taken the carbs off and cleaned yet. You can hear at certain rpm the engine sputter alittle and it is popping on the right side on deceleration. It only has 9000 miles and is still getting around 40 mpg. I think it could run alittle smoother at high rpms but it is not too bad. Any ideas?

[Neil86]

You might first inspect the synch ports on the intake runners.

If your bike has the AIS system operational, there will be 2 ports with hoses

and 2 with caps.

If the AIS is disabled all 4 ports may have caps.

Inspect all the caps and hoses for cracks....common for them to start cracking,

leaking vacuum and causing the issues you describe.

Edited August 9, 2014 by Neil86

[ACE50]

"Have a carburetor sync gage on order so that will be next."

 

Let us know if that one helps, it just might do the trick.

[Ace]

I'll second what Neil86 said. Your carbs may be way out of sync as well.

[fishrepair]

I had the same problem on my 86 1st gen and I finally ran a whole can of seafoam to 1/2 tank of gas and WOW, it straightened right out.

[Big Auggie]

When mine does that I change the synch port caps. First time it happened a mechanic sprayed carb cleaner around the carbs while it was running and the rpms increased so we knew it had a vacuum leak. I actually keep spares with me.

[jowens]

Got my carb sync gages in today. Work 2nd and couldn't wait till tomorrow. Was syncing my carbs at midnight. Well it did make a big difference and the bike runs a lot smoother but I think something is still alittle off. I did notice an improvement in the idle and the exhaust note changed on the right side. It was louder than the left, now it is about the same. The idle seems smoother. The test will be in the morning when I start it. It had gotten to the point that I had to choke it for a couple of minutes before it would idle with the choke off. Another thing I noticed before you could pull the plug wire on the right rear cylinder and there wouldn't be hardly any change in the engine rpms'. Now there is a noticeable difference in the rpms' when you pull that plug wire. The right 2 carbs were out a good bit, about 15 difference on my gauges. The left side wasn't bad, maybe 5 out. Once That was done the balance between both sides were the same so I didn't have to make that adjustment. The carb sync didn't seem to help the popping in the exhaust though, heck it may be a little worse now. One thing I failed to mention is I had the exhaust off about a month ago when I removed the rear wheel. Will pull them tomorrow and check the gaskets. Another dose of seafoam this weekend. Will give a further update later.

Edited August 13, 2014 by jowens
correct spelling

[GeorgeS]

After the work you have done, take it out for a run, and drive it " Hard " !!!

 

Burn a half tank of fuel with heavy dose of Sea-Foam, then see what you have.

 

A dose of " HEET " also, just to make sure NO water in the tank.

[Neil86]

Just a suggestion....pulling a plug wire off can drive the coil voltage up to the point it will find another ground through a weak spot (insulation, or worse yet back into igniter).

[jowens]

So not good idea to pull a plug wire while it is running. Oops. Thanks for the info