Removed K&N filter and now; Solved!

[Gabriel]

I replaced the K&N filter on a 2000 Valk I bought a couple of weeks ago with the stock filter and now the bike bucks and misses at high RPM.
I checked all the usual; petcock, and any kinked or pinched lines without any fault found.
However when I pulled the K&N filter it had a foam piece on the top of it and I thought it was part of the K&N filter kit because it said in print do not oil this foam (or something like that), so I did not move it to the new filter.
In searching for a resolution based on symptoms I came across several with this issue and their problem was resolved by reinstalling the foam piece on top of the filter.
This bike did not miss before I replaced the filter and nothing else was done but the filter at that time.
One thing I did notice after replacing the filter was that the bike felt like it had about 10% more horsepower, that is until the surge kicks in...
It feels like it's starving for fuel.
Someone enlighten me on this piece of foam, please

 

[Harryc]

I've only heard of this extra piece of foam being an issue on the European version of the Valkyrie, not US. So I am curious to hear why you had it or need it. Where did this bike come from originally?

[Savago]

If it looks like this, it is part of the K&N filter:
https://goo.gl/photos/jydkzHrLDTp4q63G6

and AFAICT, should not be used on top of the OEM filter.

It may be the case you need to tune the bike for the OEM filter.

[Gabriel]

That's the one!
I bought it from the original owner and the only thing he ever did was oil changes and removed the pigs
I'm doing/done everything else, fluids, filters, plugs, carb sync and so on.
I don't know when he installed the K&N but it may have been a long time ago?
I pulled the petcock and the tank is pristine, so was the sock, I modified the stock valve to manual and all of this works great except for the surge I picked up after replacing the air filter, I also pick up some noticeable power from this change.
I pulled the carb diaphragms on the right side to check for a tear or broken spring, I'll do the left tonight or tomorrow.
I doubt any of this will matter unless that K&N was masking some other problem.
BTW; this is a US made bike, I did not know it was European only for the foam addition to the filter.
I should say at this point that;
I'm a retired Master ASE tech, Master Registered tech (European equivalent), and the last five years before I retired I was a Professor of auto technology on a tenure track at the local Collage.
State curriculum writing.
All this means is I should know what I'm doing, but all it really means is I should at lease understand what you guys are trying to tell me.

Thank you for clearing that filter thing up for me.  ✞

[Bighead]

That's the one!
I bought it from the original owner and the only thing he ever did was oil changes and removed the pigs
I'm doing/done everything else, fluids, filters, plugs, carb sync and so on.
I don't know when he installed the K&N but it may have been a long time ago?
I pulled the petcock and the tank is pristine, so was the sock, I modified the stock valve to manual and all of this works great except for the surge I picked up after replacing the air filter, I also pick up some noticeable power from this change.
I pulled the carb diaphragms on the right side to check for a tear or broken spring, I'll do the left tonight or tomorrow.
I doubt any of this will matter unless that K&N was masking some other problem.
BTW; this is a US made bike, I did not know it was European only for the foam addition to the filter.
I should say at this point that;
I'm a retired Master ASE tech, Master Registered tech (European equivalent), and the last five years before I retired I was a Professor of auto technology on a tenure track at the local Collage.
State curriculum writing.
All this means is I should know what I'm doing, but all it really means is I should at lease understand what you guys are trying to tell me.

Thank you for clearing that filter thing up for me.  ✞

Doesn't the A in ASE stand for automotive? just bustin your chops a bit

[Gabriel]

Your right!
I worked for VW/Porsche/Audi and then I went to Honda for five years...

[98valk]

either filter will make no difference.

since u modified the petcock, dble check it.  sounds like its running out of fuel on the top end.

[Gabriel]

I made the valve mod today.
It was day before yesterday I did the filter change and only the filter.
This was the only change that caused this surge...
BTW; the surge is the same if I have two quarts or five gallons in the tank.
I flow tested the valve, it's not a problem 

[Harryc]

What happens if you put the K&N back in and take it for a ride? If it fixes the issue, the easiest solution is to clean and recharge the K&N, install it and call it a day.  (So says the back yard mechanic. )

[Gabriel]

I thought about that, but the tank is full again and you know how that goes.
I may do it soon, just to see...
Edit:
I believe that the K&N has been in for a long time, I also believe it was restricted and masked a lean condition. How else could I account for the improvement in performance.
The bike was already running lean at HWY speeds because the plug insulators are white.
I adjust the idle circuit mixture and synced the carbs already also.

[Harryc]

Worth a shot. If you are not the original owner it's hard to say what someone might have done to use the K&N. Theoretically it should require no modifications but who knows....maybe someone rejetted for it. Check your plugs for color too.

[Gabriel]

I edited the post above and added the information about the plugs

[Harryc]

Does this bike have stock pipes?

[sandy]

When you check the diaphragms, check to see if you have dynajet needles or stock ones. Also see if there are 2 washers under the needles. Only one thin one is stock Honda.

[98valk]

I thought about that, but the tank is full again and you know how that goes.
I may do it soon, just to see...
Edit:
I believe that the K&N has been in for a long time, I also believe it was restricted and masked a lean condition. How else could I account for the improvement in performance.
The bike was already running lean at HWY speeds because the plug insulators are white.
I adjust the idle circuit mixture and synced the carbs already also.

"The bike was already running lean at HWY speeds because the plug insulators are white."

means nothing with todays fuels. these bikes are a little rich on the main jets for safety. honda doesn't know where/how the bike will be ridden.
make sure tank vent tube is unobstructed. check spark plug wire connections at coils, esp. side coil which could have been hit during tank removal/install.

[Gabriel]

I thought about that, but the tank is full again and you know how that goes.
I may do it soon, just to see...
Edit:
I believe that the K&N has been in for a long time, I also believe it was restricted and masked a lean condition. How else could I account for the improvement in performance.
The bike was already running lean at HWY speeds because the plug insulators are white.
I adjust the idle circuit mixture and synced the carbs already also.

"The bike was already running lean at HWY speeds because the plug insulators are white."

means nothing with todays fuels. these bikes are a little rich on the main jets for safety. honda doesn't know where/how the bike will be ridden.
make sure tank vent tube is unobstructed. check spark plug wire connections at coils, esp. side coil which could have been hit during tank removal/install.

I could be wrong about the plugs, it's unlikely!

[Gabriel]

My original question here was about the air cleaner foam and that question was answered.
Thanks for all the help, I will post back here with a resolution as soon as I find it.
Thanks again...

[Firefighter]

I used K&N filter at one time with no foam, I don't like K&N so went to stock with no change in the way the engine runs. If you haven't already, I would back check and make sure the air filter box and cover have not been modified and are installed correctly. Make sure you have not loosened something somewhere or cracked a vacuum hose, etc. Make sure the fuel line tank to carbs. is back like it was, critical on this bike.

[98valk]

I thought about that, but the tank is full again and you know how that goes.
I may do it soon, just to see...
Edit:
I believe that the K&N has been in for a long time, I also believe it was restricted and masked a lean condition. How else could I account for the improvement in performance.
The bike was already running lean at HWY speeds because the plug insulators are white.
I adjust the idle circuit mixture and synced the carbs already also.

"The bike was already running lean at HWY speeds because the plug insulators are white."

means nothing with todays fuels. these bikes are a little rich on the main jets for safety. honda doesn't know where/how the bike will be ridden.
make sure tank vent tube is unobstructed. check spark plug wire connections at coils, esp. side coil which could have been hit during tank removal/install.

I could be wrong about the plugs, it's unlikely!

had my bike on factorypro dyno last yr. it uses 4 gas. I over jetted and it was running pig rich on top end and was rich at all throttle positions. insulator white-grayish white with very little darker color. much written out there about very little plug color due to today's modern ethanol fuel. even stock before I started modifying the plugs were always same color for the most part.
one site http://www.jetsrus.com/FAQs/FAQ_spark_plugs.htm
I'm sure after hitting WOT u shut off the engine and coast to a stop and check the plugs right there for a correct reading.

"We're looking for a colored ring right at the base of that porcelain which I refer to as a Fuel Ring.  The color will vary depending on the type of fuel your burning, Unleaded Pump gas will leave very little color because of all the additives such as injector cleaners and methanol.  Most of us run a 108 or 110 in our bracket cars and these fuels will leave a tan color"
http://www.4secondsflat.com/Spark_plug_reading.html

[Savago]

Maybe the breath tube (the smaller one at the top/back of the tank) got kinked (and at high speed will not allow air to get into the tank)?

[Gabriel]

Maybe the breath tube (the smaller one at the top/back of the tank) got kinked (and at high speed will not allow air to get into the tank)?

I checked all the lines and hoses, I completely removed the rear tank hose and noticed the secondary T fitting, I'm sure they did this in case the main became plugged? I checked the line that is in the tank also.
I triple checked everything I did but to me this is a really simple operation, of course that does not mean I did not screw something up while in there but outside of removing the tank replacing the air cleaner is pretty easy.
After modifying the petcock to manual there are only two hoses to worry about and even if you left the vent hose completely off it would not matter.
I might have a partially clogged main jet?
But first:
I may put the K&N back in tomorrow just to see...

[Gabriel]

I thought about that, but the tank is full again and you know how that goes.
I may do it soon, just to see...
Edit:
I believe that the K&N has been in for a long time, I also believe it was restricted and masked a lean condition. How else could I account for the improvement in performance.
The bike was already running lean at HWY speeds because the plug insulators are white.
I adjust the idle circuit mixture and synced the carbs already also.

 

"The bike was already running lean at HWY speeds because the plug insulators are white."

means nothing with todays fuels. these bikes are a little rich on the main jets for safety. honda doesn't know where/how the bike will be ridden.
make sure tank vent tube is unobstructed. check spark plug wire connections at coils, esp. side coil which could have been hit during tank removal/install.

I could be wrong about the plugs, it's unlikely!

had my bike on factorypro dyno last yr. it uses 4 gas. I over jetted and it was running pig rich on top end and was rich at all throttle positions. insulator white-grayish white with very little darker color. much written out there about very little plug color due to today's modern ethanol fuel. even stock before I started modifying the plugs were always same color for the most part.
one site http://www.jetsrus.com/FAQs/FAQ_spark_plugs.htm
I'm sure after hitting WOT u shut off the engine and coast to a stop and check the plugs right there for a correct reading.

"We're looking for a colored ring right at the base of that porcelain which I refer to as a Fuel Ring.  The color will vary depending on the type of fuel your burning, Unleaded Pump gas will leave very little color because of all the additives such as injector cleaners and methanol.  Most of us run a 108 or 110 in our bracket cars and these fuels will leave a tan color"
http://www.4secondsflat.com/Spark_plug_reading.html

Reading spark plugs in 2017 is still a valid method to determine combustion condition.
Quote from NGK;
"How do I read a spark plug?

A: Being able to "read" a spark plug can be a valuable tuning aid. By examining the insulator firing nose color, an experienced engine tuner can determine a great deal about the engine's overall operating condition.

In general, a light tan/gray color tells you that the spark plug is operating at optimum temperature and that the engine is in good condition. Dark coloring, such as heavy black wet or dry deposits, can indicate an overly rich condition, too cold a heat range spark plug, a possible vacuum leak, low compression, overly retarded timing or too large a plug gap.

If the deposits are wet, it can be an indication of a breached head gasket, poor oil control from ring or valvetrain problems or an extremely rich condition—depending on the nature of the liquid present at the firing tip.

Signs of fouling or excessive heat must be traced quickly to prevent further deterioration of performance and possible engine damage."
https://www.ngksparkplugs.com/about-ngk/faqs/spark-plug-faqs/how-do-i-read-a-spark-plug

[Harryc]

After modifying the petcock to manual there are only two hoses to worry about ...

 The vacuum line (from the old petcock) needs to be blocked off or removed and plugged at the crankcase. I didn't feel like reading this entire thread again, but if you didn't do that you have a large vacuum leak. That will screw up performance for sure.

[The emperor has no clothes]

After modifying the petcock to manual there are only two hoses to worry about ...

 That vacuum line needs to be blocked off or removed and plugged at the crankcase.

I THINK he meant the 2 hoses are the fuel line and the vent hose. If the vent hose were left off it should still operate fine. But as you say, the vacuum line from #6 does need to be blocked off.

[Gabriel]

I  capped the #6 vacuum port.

The K&N filter is back in, it's raining now so it will be tomorrow to find out...
 

[svsteve]

I just did a cleaning to my K&N and found my pre filter falling apart. That's the foam piece that covers the filter. I called K&N customer service and asked about it. The lady I talked to knew what I needed and sent me a new 1 no charge. The K&N is a lifetime filter. Give them a call, they'll make it right.

[Gabriel]

As I said earlier that I reinstalled the K&N filter and now it runs like it did before, no miss or surge.
It runs like a scalded dog all the way to the rev limiter.
This tells me that the K&N filter is restricted, not that it's a bad filter but it could have been in there for many years.
I ordered 38's, 105's and IS springs, when they arrive I'm put them in and the OEM filter back on.

I looked up the exhaust with a flash light and discovered that more than the piggies are missing, there is also so baffle wall missing, so this bike probably has some pretty free flowing exhaust, which would explain the need to fatten up a little.
Mystery solved

BTW; this website is down often for me.

[The emperor has no clothes]

As I said earlier that I reinstalled the K&N filter and now it runs like it did before, no miss or surge.
It runs like a scalded dog all the way to the rev limiter.
This tells me that the K&N filter is restricted, not that it's a bad filter but it could have been in there for many years.
I ordered 38's, 105's and IS springs, when they arrive I'm put them in and the OEM filter back on.

I looked up the exhaust with a flash light and discovered that more than the piggies are missing, there is also so baffle wall missing, so this bike probably has some pretty free flowing exhaust, which would explain the need to fatten up a little.
Mystery solved

BTW; this website is down often for me.

We seem to be having some issues lately. Sounds like you have the problem solved. It seems strange that the K&N would flow less air than a stock filter.

[Harryc]

Glad you got the problem figured out. Please let us know if jetting fixes the issue. Just a hunch, but I'd not be surprised if you put the exhaust back to stock instead of jetting you'd get good results with a stock filter as well.  Anyone who guts an exhaust in effect making straight flowing pipes and does not jet is misinformed at best.  9 times out of 10 it's going to kill your top end. The dirty/blocked K&N was just masking the problem like you said earlier.

[Gabriel]

Glad you got the problem figured out. Please let us know if jetting fixes the issue. Just a hunch, but I'd not be surprised if you put the exhaust back to stock instead of jetting you'd get good results with a stock filter as well.  Anyone who guts an exhaust in effect making straight flowing pipes and does not jet is misinformed at best.  9 times out of 10 it's going to kill your top end. The dirty/blocked K&N was just masking the problem like you said earlier.

I wish it had stock exhaust, it's loud!
I'll do something with the exhaust soon

[Harryc]

I wish it had stock exhaust, it's loud!
I'll do something with the exhaust soon

I hear you Gabriel. Just a word of advice. Figure out what exhaust you want and then jet...not the other way around.  A free flowing exhaust will require different jetting than a restricted exhaust. Same for air filters. Free flowing vs restricted. It's a balancing act, and depending on the setup may require you to rejet several times to get it right, or close to right.  My bike has a completely stock intake (except for doing a desmog) and exhaust for a good reason. I've done the jetting game on previous bikes I've owned. It's fun and frustrating at the same time. Been there done that. At the end of the day I took my ball and went home from that game.

[Gavin_Sons]

I wish it had stock exhaust, it's loud!
I'll do something with the exhaust soon

I hear you Gabriel. Just a word of advice. Figure out what exhaust you want and then jet...not the other way around.  A free flowing exhaust will require different jetting than a restricted exhaust. Same for air filters. Free flowing vs restricted. It's a balancing act, and depending on the setup may require you to rejet several times to get it right, or close to right.  My bike has a completely stock intake (except for doing a desmog) and exhaust for a good reason. I've done the jetting game on previous bikes I've owned. It's fun and frustrating at the same time. Been there done that. At the end of the day I took my ball and went home from that game.

My stock exhaust are cut off right behind the front baffle. Open truck stacks from there out to 2 inches behind the saddle bags. I did not rejet, had to adjust my mixture screws and do a carb sync though. Id try tuning each carb with the mixture screw before a rejet another reason the stock filter may not be working properly is there could be a seal stuck from an old filter and you are trying to fit 2 seals in the slot and not making a good seal

[Gabriel]

The front baffle and it's associated tubes is the only one that is intact, I took the tip off and notice both mufflers are cut off at the point where the piggy's mounted and some of the center baffle is missing also.  (no extra air filter seal remaining)

I'm probably going to do a glass pack and leave that front baffle as it is, so it will always be free flowing, I'm hoping to quiet it down a bit...

Adjusting the mixture circuit only affects Idle and some low speed, so they won't help the high end.

[Harryc]

Adjusting the mixture circuit only affects Idle and some low speed, so they won't help the high end.

You get it ... good luck.

[gordonv]

As for the mufflers.

http://www.valkyrieforum.com/bbs/index.php/topic,90752.0.html

Read the above.

[rocketray]

yes I put in a K/N but ...after a $1,500 carb rebuild ad nauseaum....I had over sprayed the K/N filter w/oil and resultant lack of O2 to the motor...ditch it ..and see how it runs

[MarkT]

I understood a couple decades ago when I installed the K&N on Deerslayer, that the foam prefilter was to add restriction to make the K&N breathe same as an OEM filter. That is, to address complaints from customers who install a free-flowing filter then complain the bike needs rejetting thanks to the filter.  It breathes better with the K&N, service interval is silly - like 100k miles - and service is cleaning and re-oiling it. I suspect it passes more dirt - seems obvious to me. So I would suspect you might see some tuning issues as a function of prefilter installed or no, with a K&N filter.  Maybe affects an OEM filter too.

As for dropping backpressure changing the mixture - not necessarily.  Depends on other factors too.  i.e., the OEM exhaust is 6-6.  Removing the baffles, installing a header collector and a free-flow glasspack recovers the energy wasted pushing exhaust against the OEM baffles.  It also changes the config to 6-2 which adds scavenging not extant with the OEM exhaust.  That prevents getting a too-thin mixture from reducing the backpressure. The net result is moe noticable power and a mixture that remains about the same.  Which is generally rather thin to begin with esp. at low altitude thx to the EPA. Not here at our altitude in CO.  I'm right at 2Km high - mixture is about perfect per plug readings, with stock jets.

[chrise2469]

I.ve a dumb question that nobody asked.  When your replaced the K&N with the stock, did you also replace the gaskets with the stock filter.  K&N has you remove a gasket  (17213-MZ0-000) from each side of the airbox.  Without the gaskets I'm guessing you may have some airflow issues.

[Gabriel]

I.ve a dumb question that nobody asked.  When your replaced the K&N with the stock, did you also replace the gaskets with the stock filter.  K&N has you remove a gasket  (17213-MZ0-000) from each side of the airbox.  Without the gaskets I'm guessing you may have some airflow issues.

Good call, it looks like there are two of them, one on each side.
I had no idea there were additional gaskets, I've never seen an application that took gaskets other than the seal lip around the air cleaner.
K&N wants you to modify the bike to use their product?
I need to see if they are there or not next week when I go through the carbs, actually depends on when the parts arrive.
I can tell the bike is still lean because even though there is no surge in 1st or 2nd a very slight surge shows up in 3rd and fourth above 6K.
Thanks...
Edit; I have two on the way...

[The emperor has no clothes]

I.ve a dumb question that nobody asked.  When your replaced the K&N with the stock, did you also replace the gaskets with the stock filter.  K&N has you remove a gasket  (17213-MZ0-000) from each side of the airbox.  Without the gaskets I'm guessing you may have some airflow issues.

Good call, it looks like there are two of them, one on each side.
I had no idea there were additional gaskets, I've never seen an application that took gaskets other than the seal lip around the air cleaner.
K&N wants you to modify the bike to use their product?
I need to see if they are there or not next week when I go through the carbs, actually depends on when the parts arrive.
I can tell the bike is still lean because even though there is no surge in 1st or 2nd a very slight surge shows up in 3rd and fourth above 6K.
Thanks...
Edit; I have two on the way...

If you didnt put them on with the stock filter thats got to be the problem. They won`t fit with the K&N. I wouldn`t figure it would change the leanness that much. I would have thought it would just be a problem of dirt getting in.