HELP. Idle poping and coughing

[Rilcoat]

I have a 2001 venture. Stock except for k&N filters. I just Bought the bike and have no history. It has 23000 miles. At idle hot it idles a bit rough and you can hear the exhaust popping and coughing. Under load when driving it seems okay. I have checked the carb sync and it was very hard to get it close. I removed the carbs and found one diaphram was crimped a little bit. I cleaned the carbs put everything back and it still does it. Plugs are brand new. Sprayed carb cleaner around while idle and found no leaks.

Don’t know where to go next.

[CaseyJ955]

I have a 2001 venture. Stock except for k&N filters. I just Bought the bike and have no history. It has 23000 miles. At idle hot it idles a bit rough and you can hear the exhaust popping and coughing. Under load when driving it seems okay. I have checked the carb sync and it was very hard to get it close. I removed the carbs and found one diaphram was crimped a little bit. I cleaned the carbs put everything back and it still does it. Plugs are brand new. Sprayed carb cleaner around while idle and found no leaks.

Don’t know where to go next.

 

Just for fun, if you have the paper OEM air filter go ahead and throw that in and see what happens. The K&N may not be providing enough resistance to flow, the CV carbs rely on that to run right. There is a workaround for this, but try that first and see if it goes in the right direction.

 

A workaround, if this turns out to be related to the air filter being to free flowing. See the extra brass bit next to the jet, ya get those and slip them in and they fool the carb into playing nice with a free flowing air filter. Here is a pic of the filter that replaces the lid on my Vmax (Same as Venture carbs). I think the plugs are like $20 from Morleys Muscle. When I tried a K&N in my Venture I ended up going back to paper OEM filter. Food for thought.

Edited August 9, 2020 by CaseyJ955

[Rilcoat]

Just for fun, if you have the paper OEM air filter go ahead and throw that in and see what happens. The K&N may not be providing enough resistance to flow, the CV carbs rely on that to run right. There is a workaround for this, but try that first and see if it goes in the right direction.

 

A workaround, if this turns out to be related to the air filter being to free flowing. See the extra brass bit next to the jet, ya get those and slip them in and they fool the carb into playing nice with a free flowing air filter. Here is a pic of the filter that replaces the lid on my Vmax (Same as Venture carbs). I think the plugs are like $20 from Morleys Muscle. When I tried a K&N in my Venture I ended up going back to paper OEM filter. Food for thought.

 

i have a small problem. I never had the oem filter or housing that came with the bike.

[videoarizona]

I would imagine, someone has a spare intake floating around.

 

BUT, in the meantime....take the KN out and clean it up. When dry, put it back in temporarily and see how it runs. Without the oil, it might not be as restrictive and maybe give you an idea if the restriction of the wet K&N is the problem with your spitting and backfiring. We expect a little back fire as the carbs are set to run lean anyway.

 

hopefully, someone will find an original air intake assembly floating around...and you can go from there.

[Rilcoat]

I would imagine, someone has a spare intake floating around.

 

BUT, in the meantime....take the KN out and clean it up. When dry, put it back in temporarily and see how it runs. Without the oil, it might not be as restrictive and maybe give you an idea if the restriction of the wet K&N is the problem with your spitting and backfiring. We expect a little back fire as the carbs are set to run lean anyway.

 

hopefully, someone will find an original air intake assembly floating around...and you can go from there.

 

The air filters are clean. I just checked them. I find it hard to believe that an air filter is causing this. At idle it is constantly coughing and poping through the tail pipe. I also cant seem to get the carbs to sync. I get it synced and then the idle is out drastically. I adjust the idle and the sync goes out and the only way to stop the pop and cough is to raise the idle to 1500 rpms. Even after a small blip it seems to hold the higher rpm for a minute. If i rev real hard as soon as i let the throttle go it crackles all the way to idle

[CaseyJ955]

The air filters are clean. I just checked them. I find it hard to believe that an air filter is causing this. At idle it is constantly coughing and poping through the tail pipe. I also cant seem to get the carbs to sync. I get it synced and then the idle is out drastically. I adjust the idle and the sync goes out and the only way to stop the pop and cough is to raise the idle to 1500 rpms. Even after a small blip it seems to hold the higher rpm for a minute. If i rev real hard as soon as i let the throttle go it crackles all the way to idle

 

Pods, for some reason I was thinking a drop-in, sorry. Yea, I would start with the air correctors or getting an OEM airbox and filter.

I got my correctors from Morleys Muscle, ya just tap them in and seat them. You can remove them later but are not reusable after removed. Just four little brass thingies and my guess is you will be happy, as you would be if you found an OEM airbox. Either way and I'm pretty sure you will see a real improvement.

 

http://www.morleysmuscle.com/ I'll bet he has some in stock. I tuned my Vmax with all his stuff and I'm pretty darn pleased with it.

[steamer]

you might want to start with the basics and check for air leaks. make sure the carbs are seated in the rubber intake manifolds, its easy to not get a proper seal when re installing the carbs. also all the lines to the ais system. if the exhaust pipes have pinholes in them that will cause popping. the back "y" pipes are made with a mild steel tubing and can rust out. the front tubes are stainless our something like that, don't know why they designed them that way. try running some seafoam with a couple of tanks of gas it does help clean the carbs.

[Rilcoat]

you might want to start with the basics and check for air leaks. make sure the carbs are seated in the rubber intake manifolds, its easy to not get a proper seal when re installing the carbs. also all the lines to the ais system. if the exhaust pipes have pinholes in them that will cause popping. the back "y" pipes are made with a mild steel tubing and can rust out. the front tubes are stainless our something like that, don't know why they designed them that way. try running some seafoam with a couple of tanks of gas it does help clean the carbs.

 

I re started the bike after everything was put back together. Bike ran really nice. Idle was a little low. Once the bike reached operating temperature it was backfiring through the tail pipe non stop. I will see if the stock air filters will fit the k&n chrome covers on a venture.

[luvmy40]

I'm running K&N air filters on an otherwise stock '06 RSV and the only popping I get is on decel due to a slight exhaust leak on the right slip on muffler.

[videoarizona]

You are running rich. For sure.

[Rilcoat]

I took it out for a while tonight. It has no issues on acceleration or cruising at city or highway speeds. Seems everytime I came to a stop the idle was increased a bit and I still had the puff puff puff through the exhaust. Does it through both pipes. Lets just say it idles poorly. No backfiring on decel.

[Marcarl]

I'm going out on a limb here to say that the sync is still out. If you are having the issues you stated then one of 2 things would be the cause, but I am just thinking fro here, and that isn't anywhere's near your place.

First, there is an air leak below the buuterflies.

Two, you are turning on the wrong screws at the wrong time. First set # 2 to #1 , so the left side of the engine as you sit on the bike. Keep the idle around 950.

Then adjust the right (as you sit on the bike) side of the bike, so that 3 and 4 match each other and the match on 1 and 2 hasn't changed. Then match the right side to the left side. If done correctly and there are no leaks there should be no change. As you adjust the sync, blip the throttle to get the linkage between then to seat properly. Also, if the throttle linkage is dirty, rusted or otherwise impaired, that could also cause some issues. When you are doing a sync, all you are doing is adjusting the opening of the butterflies or throttle plates. Maybe this will help.

[Guest divey]

I will see if the stock air filters will fit the k&n chrome covers on a venture.

I’m pretty sure they don’t.

Correction - I may be wrong. I was thinking K&N filters won’t fit in a stock set up.

Edited August 10, 2020 by divey

[CaseyJ955]

I'm running K&N air filters on an otherwise stock '06 RSV and the only popping I get is on decel due to a slight exhaust leak on the right slip on muffler.

 

That is cool, your running pods with no other mods/tuning changes? No adjustment to the AF screws or anything?

 

It jumped off the page to me because his description of the issue does match the very common result of the modification he also described.

 

If I were in his neck of the woods I'd be at his door with an airbox under my arm to confirm or RO the filter assy as the culprit. Without standing in front of the bike it's hard to know anything 100% but this rings very familiar with my Yammy V4 experiences and many other Yamaha V4 forum posts I perused as I considered what to do with my own bikes. It could be any number of things but in my own experience the pods are overwhelmingly likely to be causing his troubles. (or some of his troubles).

 

I recall a post with pics of a VMX with pods and the same Sx described by the OP, he partially covered the pods with aluminum foil and found it suddenly ran great with this band-aid. The OP stated it was hard to get a sync as it sits, I also had to replace the airbox/filter (Venture) or use correctors (Vmax) to be able to put a satisfactory tune on either. I live at 4000' elevation and tune a little lean.

Edited August 10, 2020 by CaseyJ955

[cowpuc]

All definitely worthy advice IMHO with not much constructive advice to add except for this one thing.. If it were mine I would warm it up really really good,, to full operating temp and then do a stator/rectifier check on it just for kicks. Simple test with vlt/ohm meter.. Hook er up,, touch the throttle and make sure your seeing it snap right to 14 voltsish when the regulator hits at around 2 grand.. No sluggishness,, it should jump right to attention.. Another old school way of checking it,, that I have used since I was a kid is just watch the headlight in a dark garage and make sure it is responding instantly and consistently when the stator sends the high voltage produced to the reg as it hits the correct R's.. One of my theories having to do with stator life and performance is that once those stator windings have become burnt from getting hot they lose their ability to resist current leakage across the windings which causes reduced signal being sent to the rectifier which results in irratic and/or slow response to charge the system including battery.. This can and has in my case resulted in one strange running scoot at idle and right off idle until the stator catches up - case worsens as the bike warms up.. IMHO, this has also been a prelude to a completely failed stator.. Note - battery ignition bikes are most susceptable to this..

Another thing that I would also do/check is corrosion at the plug wire ends.. Little extra resistance there can cause the same issues.. I customarilly will snip off a small amount at wires end going into the cap at any sign of corrostion there to prevent such malidies and am also very liberal in keeping good/new NGK caps on my plugs..

Probably wayyy out there in left field in suggesting such nonsense but I would just do it...

[Rilcoat]

That is cool, your running pods with no other mods/tuning changes? No adjustment to the AF screws or anything?

 

It jumped off the page to me because his description of the issue does match the very common result of the modification he also described.

 

If I were in his neck of the woods I'd be at his door with an airbox under my arm to confirm or RO the filter assy as the culprit. Without standing in front of the bike it's hard to know anything 100% but this rings very familiar with my Yammy V4 experiences and many other Yamaha V4 forum posts I perused as I considered what to do with my own bikes. It could be any number of things but in my own experience the pods are overwhelmingly likely to be causing his troubles. (or some of his troubles).

 

I recall a post with pics of a VMX with pods and the same Sx described by the OP, he partially covered the pods with aluminum foil and found it suddenly ran great with this band-aid. The OP stated it was hard to get a sync as it sits, I also had to replace the airbox/filter (Venture) or use correctors (Vmax) to be able to put a satisfactory tune on either. I live at 4000' elevation and tune a little lean.

 

Not sure why you think I have pods. All I have is k@n air filters in the housing

[luvmy40]

That is cool, your running pods with no other mods/tuning changes? No adjustment to the AF screws or anything?

 

It jumped off the page to me because his description of the issue does match the very common result of the modification he also described.

 

If I were in his neck of the woods I'd be at his door with an airbox under my arm to confirm or RO the filter assy as the culprit. Without standing in front of the bike it's hard to know anything 100% but this rings very familiar with my Yammy V4 experiences and many other Yamaha V4 forum posts I perused as I considered what to do with my own bikes. It could be any number of things but in my own experience the pods are overwhelmingly likely to be causing his troubles. (or some of his troubles).

 

I recall a post with pics of a VMX with pods and the same Sx described by the OP, he partially covered the pods with aluminum foil and found it suddenly ran great with this band-aid. The OP stated it was hard to get a sync as it sits, I also had to replace the airbox/filter (Venture) or use correctors (Vmax) to be able to put a satisfactory tune on either. I live at 4000' elevation and tune a little lean.

 

No, not pods. We are talking Gen 2 RSVs. The K&N filters are just cleanable/reusable versions of the factory filters. They may have higher flow ratings than the OEM filters but they do not modify the air flow the way pods in lieu of the air box and filter would on a Gen 1.

[Guest divey]

I'm going out on a limb here to say that the sync is still out. If you are having the issues you stated then one of 2 things would be the cause, but I am just thinking fro here, and that isn't anywhere's near your place.

First, there is an air leak below the buuterflies.

Two, you are turning on the wrong screws at the wrong time. First set # 2 to #1 , so the left side of the engine as you sit on the bike. Keep the idle around 950.

Then adjust the right (as you sit on the bike) side of the bike, so that 3 and 4 match each other and the match on 1 and 2 hasn't changed. Then match the right side to the left side. If done correctly and there are no leaks there should be no change. As you adjust the sync, blip the throttle to get the linkage between then to seat properly. Also, if the throttle linkage is dirty, rusted or otherwise impaired, that could also cause some issues. When you are doing a sync, all you are doing is adjusting the opening of the butterflies or throttle plates. Maybe this will help.

@Rilcoat, if you haven’t looked in the 2nd Gen. technical library at Freebird’s write up and pics on syncing the carbs, check it out. For clarification, set 2 to 1 first (from the right side of the bike) and then set 3 to 4 (also from the right side of the bike) and then adjust the two pairs (from the left side of the bike). If you think it’s possible your sync tool might be out of whack, I have one here that you’re welcome to try. I’m no carb expert but I can sync mine perfectly so if you think that could possibly be the problem, send me a PM. Doug

[Rilcoat]

No, not pods. We are talking Gen 2 RSVs. The K&N filters are just cleanable/reusable versions of the factory filters. They may have higher flow ratings than the OEM filters but they do not modify the air flow the way pods in lieu of the air box and filter would on a Gen 1.

 

Hi Doug. I sent you a PM.

[Rilcoat]

I just want everyone to be aware that I do not have pods. I just have K&N filters in my bike.

[Guest divey]

Hi Doug. I sent you a PM.

Just left you a message. Doug

[CaseyJ955]

No, not pods. We are talking Gen 2 RSVs. The K&N filters are just cleanable/reusable versions of the factory filters. They may have higher flow ratings than the OEM filters but they do not modify the air flow the way pods in lieu of the air box and filter would on a Gen 1.

 

I get the difference between pods and a drop-in, but when OP said filters in plural I made the logical step to pods. In my own defense, I've seen pods on everything from Geo Metros to BB stangs, I didn't want to assume that an RSV was off limits to someone looking for gains and trying pods.

[luvmy40]

Nothing to defend against. Before I got my '06 I had no idea the Gen 2 had two side mounted filters.

[CaseyJ955]

Nothing to defend against. Before I got my '06 I had no idea the Gen 2 had two side mounted filters.

 

I did not know that until just now when I read this. No wonder I sounded like a nut. I could swear the one I saw the inside of was very similar. I stand corrected.

[Patch]

calgary or that ed'thingy place?

So somthing to consider if the PO was reading a cartoon mag deciding to change filters then he may have also change jets?

the main, block or, plugs maybe loose? Know what i mean...

Casey i was right there on the same path. Couple years back we had an Auz telling us how wonderful the pods were, according to the cartoon net mag he was reading....yup yup yup