Kawasaki Vulcan Forum banner

1 - 20 of 24 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
I recently purchased a 2014 1700 Nomad ABS. I put Vance & Hines Pro Pipes on it. I did not change out the exhaust gaskets as they looked good. I also put the Cobra Fi2000 PowerPro tuner on it. The installation seemed very straight forward. I just ordered the Thunder Mfg throttle body gasket. I'm also installing a K&N replacement air filter as soon as it arrives.

Here's my problem. When I roll off the gas, I get TERRIBLE popping and backfiring, especially when I'm in the lower gears. I'm going to check for exhaust leaks tonight when I get home from work. Is there anything else I should be checking for or are there any suggestions you might think helpful? All suggestions are more than welcome! Thanks much.
 

·
Premium Member
Joined
·
1,186 Posts
General concensus is that the gasket for the TB will make a difference. I don't have much popping with the same setup and a Thunder BAK. I started getting a lot of popping, but I found that the ground for the PP had broken. Once I fixed that, the popping stopped again.
 

·
Registered
Joined
·
580 Posts
I recently purchased a 2014 1700 Nomad ABS. I put Vance & Hines Pro Pipes on it. I did not change out the exhaust gaskets as they looked good. I also put the Cobra Fi2000 PowerPro tuner on it. The installation seemed very straight forward. I just ordered the Thunder Mfg throttle body gasket. I'm also installing a K&N replacement air filter as soon as it arrives.

Here's my problem. When I roll off the gas, I get TERRIBLE popping and backfiring, especially when I'm in the lower gears. I'm going to check for exhaust leaks tonight when I get home from work. Is there anything else I should be checking for or are there any suggestions you might think helpful? All suggestions are more than welcome! Thanks much.
Just wondering if you have plugged the small air hose inside the stock cover on the right side. I always change the exhaust gaskets regardless of how good they look as they are pretty cheap and it's just easier to do it then than having to remove the pipes and redo it.
 

·
Premium Member
Joined
·
20 Posts
I had the same setup. Cobra's instruction say backfiring often relates to air leaks.

Pulled it back apart, tightened exhaust clamps down a bit more, problem reduced. Does not go away entirely.

My Thunder kit arrives Friday, hope to install this weekend.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #5
Just wondering if you have plugged the small air hose inside the stock cover on the right side. I always change the exhaust gaskets regardless of how good they look as they are pretty cheap and it's just easier to do it then than having to remove the pipes and redo it.
I didn't replace the gaskets because my Nomad is only a couple of months old. No, I didn't plug the small air hose on the right side. Are you talking about the hose that connects to the back of the case housing in the upper left corner? I had no idea that needed to be done. How should I plug it?
 

·
Registered
Joined
·
10 Posts
Discussion Starter #6
I had the same setup. Cobra's instruction say backfiring often relates to air leaks.

Pulled it back apart, tightened exhaust clamps down a bit more, problem reduced. Does not go away entirely.

My Thunder kit arrives Friday, hope to install this weekend.
Let me know how it goes.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #7
I've also read that there's some kind of silicone sealer that I can use to seal the muffler to the header pipes. Can anyone point me in the right direction? Can anyone recommend a sealer?
 

·
Premium Member
Joined
·
1,667 Posts
NOT REPLACING the exhaust port gaskets was a big mistake. The gaskets are the crush type and on the 1700's are relatively thin as compared to other types of gaskets. As a 38 1/2 year professional m/c mechanic I learned long, and I mean a long time ago DON'T re-use exhaust port gaskets.

I have NEVER had to pull an exhaust BACK OFF due to re-using old gaskets!

Also as has been mentioned plugging up the Kleen air system hose is also necessary when you have installed any type of aftermarket exhaust.

RACNRAY
 

·
Registered
Joined
·
10 Posts
Discussion Starter #9
NOT REPLACING the exhaust port gaskets was a big mistake. The gaskets are the crush type and on the 1700's are relatively thin as compared to other types of gaskets. As a 38 1/2 year professional m/c mechanic I learned long, and I mean a long time ago DON'T re-use exhaust port gaskets.

I have NEVER had to pull an exhaust BACK OFF due to re-using old gaskets!

Also as has been mentioned plugging up the Kleen air system hose is also necessary when you have installed any type of aftermarket exhaust.

RACNRAY
After some more research and reading your post, RACNRAY, all I can say is that I will NEVER again reuse the exhaust gaskets. Do you recommend any particular brand of gasket? Now, to address the Kleen air system, how do you recommend I plug that hole?
 

·
Registered
Joined
·
281 Posts
After some more research and reading your post, RACNRAY, all I can say is that I will NEVER again reuse the exhaust gaskets. Do you recommend any particular brand of gasket? Now, to address the Kleen air system, how do you recommend I plug that hole?
You can plug it with a rubber stopper same diameter as the hose, in my case my Air kit came with a small red plastic cap that fit right in the hose effectively blocking it. It is not under vaccum so it need not be glued in just needs to fit snug. :D

I know the picture sucks but that is the cap I used to block the Kleen air hose.
 

Attachments

·
Registered
Joined
·
235 Posts
NOT REPLACING the exhaust port gaskets was a big mistake. The gaskets are the crush type and on the 1700's are relatively thin as compared to other types of gaskets. As a 38 1/2 year professional m/c mechanic I learned long, and I mean a long time ago DON'T re-use exhaust port gaskets.

I have NEVER had to pull an exhaust BACK OFF due to re-using old gaskets!

Also as has been mentioned plugging up the Kleen air system hose is also necessary when you have installed any type of aftermarket exhaust.

RACNRAY
Just remember that the gaskets also go in a certain way. Someone correct me if I'm wrong but If I remember the correct way is the flat side out against the header.
 

·
Registered
Joined
·
580 Posts

·
Premium Member
Joined
·
40 Posts
You can plug it with a rubber stopper same diameter as the hose, in my case my Air kit came with a small red plastic cap that fit right in the hose effectively blocking it. It is not under vaccum so it need not be glued in just needs to fit snug. :D

I know the picture sucks but that is the cap I used to block the Kleen air hose.
I used a small piece of vacume line (2") it fit some what sug then I put a allen screw in the vacume line and it tightened it up to my liking so I knew it would not fall out, this was an easy mod since I have several vacume hoses setting around in my garage.
 

·
Premium Member
Joined
·
1,667 Posts
Just remember that the gaskets also go in a certain way. Someone correct me if I'm wrong but If I remember the correct way is the flat side out against the header.
ABSOLUTELY CORRECT!!!

The style of gaskets used by Kawi have the outer sheath rolled around the inner compressible material and there is a seam were the sheath meets. The highly and nicely machined flat section in the exhaust port is very "friendly" to that seam. If that seam is against the exhaust pipe flange I have seen exhaust system flanges separate the seam and cause leaks.

RACNRAY
 

·
Registered
Joined
·
10 Posts
Discussion Starter #15
Here's an update...

Hi all. First of all, thank you for all the helpful information. I bought a rubber stopper and plugged the Kleen Air hole. That really helped decrease the backfiring, but it didn't eliminate it completely. I did look for exhaust leaks using the the tissue paper test and I didn't find any, thank goodness.

I ordered the Thunder Mfg throttle body gasket on June 3, 2015, but it hasn't arrived yet. I did get an email yesterday saying it had been shipped so it should be here any day. I'll let everyone know how it works out.
 

·
Registered
Joined
·
86 Posts
Hmmmmmmm. I just installed a set of Vance & Hines slip on mufflers and the Gen III EJK tuner.

Took it out for a ten mile ride and it pops and carries on at deceleration - especially in the lower gears.

Have NOT installed the Thunder Mfg air kit. Not yet, anyway
 

·
Premium Member
Joined
·
337 Posts
I just did sane thing. ..V&h slipons, K&N air filter and EJK gen3 processor. Decel popping. But realized I had leak in the connection at the crossover pipe. So ordered new gasket seals for it. Now have leak in right side connection and now a broken clamp there. So waiting on new clamp to come in then will tweak the EJK and get rid of decel popping. Almost there...i see the light at the end of the tunnel
 

·
Registered
Joined
·
10 Posts
Discussion Starter #18
Hmmmmmmm. I just installed a set of Vance & Hines slip on mufflers and the Gen III EJK tuner.

Took it out for a ten mile ride and it pops and carries on at deceleration - especially in the lower gears.

Have NOT installed the Thunder Mfg air kit. Not yet, anyway
Can't emphasize this enough. That Kleen Air system on the right side has to be plugged up. If you haven't done that yet, I guarantee that's where the excess air is coming from. I didn't put the Thunder Mfg air kit on. I just replaced the air filter with a K&N. I'm waiting on the Thunder Mfg throttle body gasket to arrive. Hopefully, that will eliminate all my backfiring. Again, plugging that hole to the Kleen Air system really helped a LOT!
 

·
Registered
Joined
·
10 Posts
Discussion Starter #19
I just did sane thing. ..V&h slipons, K&N air filter and EJK gen3 processor. Decel popping. But realized I had leak in the connection at the crossover pipe. So ordered new gasket seals for it. Now have leak in right side connection and now a broken clamp there. So waiting on new clamp to come in then will tweak the EJK and get rid of decel popping. Almost there...i see the light at the end of the tunnel
Can't emphasize this enough. That Kleen Air system on the right side has to be plugged up. If you haven't done that yet, I guarantee that's where the excess air is coming from. I'm waiting on the Thunder Mfg throttle body gasket to arrive. Hopefully, that will eliminate all my backfiring. Again, plugging that hole to the Kleen Air system really helped a LOT!
 

·
Premium Member
Joined
·
337 Posts
I do have the hole plugged up on the right side....after initially forgetting all about the marbleing (see other post where I ate crow on realizing I had not done that)... nice little rubber hose plug with some silicone has the hole in the dogbowl plugged up. My issue right now is that exhaust leak that needs to be addressed. Trying to tighten down the clamp Tuesday evening the bolt in the clamp got stripped and broke right off when I was trying to manipulate it back out. So new clamp on order; should be here tuesday then I will get down to nitty gritty with the EJK. I have most (75% ??) of decel popping eliminated already, but can't do the rest until I know the exhaust system is sealed properly and can forget about that being an issue. Should only be a few more tweaks of the EJK hopefully.
 
1 - 20 of 24 Posts
Top