bike gurus needed (popping on decel)

sombo · February 11th, 2011, 10:25 PM

Ok bike gurus. I got a question for you guys. I just took my bike in for full servicing at a Kawi dealership. This included new cam chain tensionor, valve adjustment, and carb tuning. A previous owner had put on the 2-1 Yoshi exhaust and jetted the carbs and it has run like a champ for the 11k miles I've had it with no popping. Tonight however after getting it back from them I get the popping from decelerating from the higher revs. My question is: what the hell did they mess up in my carbs and how can I fix it?

Live2ride · February 11th, 2011, 10:37 PM

I'm no expert by any means, but I think this may be caused by the bike running too rich. if you shimmed the needles, you might want to go take a washer or two off of each needle, then see how it runs. If you have the jet kit you should be able to change it out so it runs more lean. You might wanna take it back to the dealer and explain that they screwed it up and what is happening since the service, then see if they will fix it for you. I'd expect that fix to be free since they messed it up.

kkim · February 12th, 2011, 02:31 AM

did they remove and reinstall the exhaust when they did the work? an air leak at the exhaust flange or further downstream can cause popping on high rpm decel.

if so, have them retorque the nuts or use some new exhaust gaskets to fix the air leak.

johnjohn · February 12th, 2011, 03:25 AM

+1 on the leak.

Alex · February 12th, 2011, 10:56 AM

/mioved to pregen tech

rockNroll · February 12th, 2011, 11:24 AM

It's common for high end performance machines to pop under decel

kkim · February 12th, 2011, 11:40 AM

Quote:

Originally Posted by rockNroll

It's common for high end performance machines to pop under decel

...but what about our ninjettes?

sombo · February 12th, 2011, 12:23 PM

Quote:

Originally Posted by kkim

did they remove and reinstall the exhaust when they did the work? an air leak at the exhaust flange or further downstream can cause popping on high rpm decel.

if so, have them retorque the nuts or use some new exhaust gaskets to fix the air leak.

Ummmm, it didn't have any gasket on it and one of the nuts was actually broke for the last 11k lol. Never had any leaks because the way the yoshi exhaust was made it stuck the pipes in the engine so far and has plate at that end it just never leaked. It's definitely something with the carbs.

Another thing was that they had to tear it apart a second time cause the first time I was leaving the place the bike died in less then half a mile and wouldn't start. Turns out that when they had it apart the first time a tiny piece of rubber had somehow gotten under the float and was causing the carbs to flood. They fixed that for free of course.

kkim · February 12th, 2011, 12:35 PM

so... did they remove the exhaust when it was there?

sombo · February 12th, 2011, 01:42 PM

Would have to. They tore the engine apart to do everything. You have to take the exhaust off just to change the oil with how the pipe is situated.

kkim · February 12th, 2011, 02:03 PM

if I were you, I'd start looking/checking to see if there are any leaks in the exhaust system before assuming it's something else, unless they changed your jetting or modified your intake system.

I always start w/ the easiest/most simple things first and move on to more involved theories/causes once the simple ones have been eliminated. don't make assumptions that can come back to bite you later... been there, done that.

you mention they did carb tuning... what exactly did they do?

sombo · February 13th, 2011, 10:02 AM

Not sure what they did with the carbs, that's just it. The 2-1 pipes are one piece the whole way back. Like I said before, it never had a gasket and only one bolt for the last 11k with no exhaust leak. I've had an exhaust leak on other vehicles and it never created a popping on decel only, just made them a bit louder and raspier. This is on high-rev decel only, like small backfire popping you see when people first put on their aftermarket exhausts and before jetting.

DaBlue1 · February 13th, 2011, 12:18 PM

Chances are the dealer, set everything by the service manual spec. Most will not tune the bike to aftermarket settings unless you tell them to.

sombo · February 13th, 2011, 06:21 PM

Quote:

Originally Posted by DaBlue1

Chances are the dealer, set everything by the service manual spec. Most will not tune the bike to aftermarket settings unless you tell them to.

That's kinda what I'm afraid of. Well I guess if they did do that it gives me a chance to try out the other jet kit I got from ztrack last year and just never put in. I'll look at the exhaust just in case but don't see how a leak would cause this.

sombo · February 17th, 2011, 07:12 PM

I apologize kkim, I think you were right after all. I was getting worse and also getting louder. I took a much closer look today at the exhaust after work (was sick the last day and a half so I didn't look then

) and I could see that the nut was coming loose. I couldn't do anything there cause I just didn't have the time or space to deal with it. When I got home I checked it again and sure enough the nut was completely gone. I called up the service department of the dealership and they were good about it. He didn't think they should have touched the exhaust but said to just bring it by and he would put it on no charge.

Didn't have enough time to make it there before they closed so I will swing by after work tomorrow.

So again, I apologize kkim, I should have just listened to the advice I was asking for. I just didn't think it would be that simple. I mean, I've had the exhaust off myself a few times and never allowed that to happen. I figured a professional service shop wouldn't make that mistake. I've also had 2 cars that had exhaust leaks and never gave popping sounds like that, just got loud. Not to mention that it never had a gasket and one broken bolt for 11k miles lol. Hey, I never said the bike (or its owner) was perfect.

kkim · February 17th, 2011, 08:22 PM

Mike... just a fellow ninjette rider trying to help out.

My advice was based on the fact that when I was switching around the exhausts on one of the 4 stroke dirt bikes about a year ago, I installed an aftermarket pipe and found out it didn't fit, put the stock pipe back on and had high rpm decel popping when I rode the bike while testing. I had not done anything else to the bike and it ran great before I played with the pipe.

I went back and used a torque wrench on all the nut and bolts on the exhaust system and the popping went away. I had hand tightened the system together positive that I knew what was right.

Needless to say, I always use a torque wrench now.

Popping/backfiring can be caused by many things. My advice on checking the exhaust was because it was the easiest of the things to check. It may have not been the exhaust, in your case, but I always try to work from the easiest to the more complex solutions first. It has saved a lot of time and headaches over the years from just guessing.

Glad you found the problem and I hope the bike is back running as well/better than it was before the popping started. Enjoy!

sombo · February 17th, 2011, 09:39 PM

I will find out tomorrow after work. I wonder if they got out the broken bolt at all. It broke on the first oil change when a friend was helping me. It broke while he was hand tightening it and not even cross-threaded. We were all confused at that point as we all witnessed it. He hadn't even brought up the wrench and the bolt popped. Yay for random metal fatigue I suppose. But it's been fine with just the one keeping tight till now. Hopefully this cures it cause holy crap is that annoying when it pops while decelerating or engine braking.

sombo · February 22nd, 2011, 07:53 PM

**UPDATE**

Ok, so I took it back to the service shop that Friday after work. They took in and found out not only was the nut missing from one bolt and a bolt broken on the other side like I said, but there is so much corrosion on the bolts that there is more then one broken. They were able to make it work with running a secondary bolt and securing others. They said it's fine for now but I will need to get it taken care of eventually with them drilling out the broken one, and putting in all new hardware. They also showed me that one of my forks is starting to leak. It's just damp which they said is ok for now, but to not let it go for too long. He said he would get me an estimate on the work for them, but I haven't received one from them yet. They didn't charge me for the repairs to the exhaust and all the popping is gone.

I also stopped by a different shop that I know does their own fork work (only one I could find in Orlando that does it seems) and got an estimate on getting them rebuilt and maybe even stiffened. If I get the racetech springs through them and have them do all the work it would be around $435 or so. The springs themselves through them would cost about $103 he said. I was also considering looking for some springs from a Ninja 500 as suggested by the other 250 site. I also need to find a good junction box cause mine is going bad (intermittently blows the headlight fuse if I use the high-beam, already had someone else diagnose it to that) and a new horn. The horn is just basically worn out and dead, so I want to replace it with a louder one.

As you can see it's not a perfect bike, needs stuff here and there. But all in all I love my bike and will be doing my best to schedule in all this work it needs to make her run nice and smooth.

kkim · February 22nd, 2011, 08:04 PM

Mike,

do you want to do the fork work to upgrade the bike or are you doing it only because of the seal leak?

what if there was a way to maybe fix the leaking fork seal w/o disassembling the forks?

Cuongism · February 23rd, 2011, 09:01 AM

When my left fork was leaking, I just replaced the fork seals, dust wipers and put in heavier fork oil. I also steel wooled any bumps found on the forks. 6k miles later and still no more leak. Total cost was about $40 total for parts and then my own labor.
If you're not looking to upgrade the suspension, I don't think you need new springs. Good luck with it though

And Kelly, there's a way to stop a leak without disassembling the forks??

sombo · February 23rd, 2011, 10:18 AM

First, I don't have the tools, area, or knowhow to do it myself. Second, it's always been my plan to eventually upgrade the forks cause I want to lesson the front end dive. You have to realize they have 17k miles on them and I'm also around 200+ pounds, the front end tends to dive a bit lol.

Also kkim I believe in doing the job right and not just throwing a bandaid on it. What the guy showed me is that to do the job right there are 3 other parts inside the forks you should replace besides the seals. The forks have 17k miles on them and need to be serviced fully imo.

kkim · February 23rd, 2011, 10:35 AM

Quote:

Originally Posted by sombo

Also kkim I believe in doing the job right and not just throwing a bandaid on it. What the guy showed me is that to do the job right there are 3 other parts inside the forks you should replace besides the seals. The forks have 17k miles on them and need to be serviced fully imo.

ah, okay.

February 11th, 2011, 10:25 PM	#1
sombo Newb..... on a steeek! :D Name: Mike Location: Windermere, FL Join Date: Feb 2009 Motorcycle(s): 2012 Harley Davidson XL883L Sportster Superlow Posts: A lot.	bike gurus needed (popping on decel) Ok bike gurus. I got a question for you guys. I just took my bike in for full servicing at a Kawi dealership. This included new cam chain tensionor, valve adjustment, and carb tuning. A previous owner had put on the 2-1 Yoshi exhaust and jetted the carbs and it has run like a champ for the 11k miles I've had it with no popping. Tonight however after getting it back from them I get the popping from decelerating from the higher revs. My question is: what the hell did they mess up in my carbs and how can I fix it?

February 11th, 2011, 10:37 PM	#2
Live2ride ninjette.org certified postwhore Name: Cody Location: NoVa Join Date: Jan 2011 Motorcycle(s): 06 yzf r6r previously: 09 ninja 250r, black 07 zx6r Posts: A lot.	I'm no expert by any means, but I think this may be caused by the bike running too rich. if you shimmed the needles, you might want to go take a washer or two off of each needle, then see how it runs. If you have the jet kit you should be able to change it out so it runs more lean. You might wanna take it back to the dealer and explain that they screwed it up and what is happening since the service, then see if they will fix it for you. I'd expect that fix to be free since they messed it up. __________________________________________________

February 12th, 2011, 10:56 AM	#5
Alex ninjette.org dude Name: 1 guess :-) Location: SF Bay Area Join Date: Jun 2008 Motorcycle(s): '13 Ninja 300 (white, the fastest color!), '13 R1200RT, '14 CRF250L, '12 TT-R125LE Posts: Too much. Blog Entries: 7	/mioved to pregen tech __________________________________________________ Montgomery Street Motorcycle Club / cal24.com / crf250l.org / ninjette.org ninjette.org Terms of Service Shopping for motorcycle parts or equipment? Come here first. The friendliest Ninja 250R/300/400 forum on the internet! (especially Unregistered)

February 12th, 2011, 11:24 AM	#6
rockNroll . Name: rock Location: greenville, south carolina Join Date: Jun 2009 Motorcycle(s): black Posts: A lot.	It's common for high end performance machines to pop under decel __________________________________________________ Always get a second opinion because most of these people are makin' this stuff up

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February 12th, 2011, 02:31 AM	#3
kkim Join Date: Nov 2008 Posts: Too much.	did they remove and reinstall the exhaust when they did the work? an air leak at the exhaust flange or further downstream can cause popping on high rpm decel. if so, have them retorque the nuts or use some new exhaust gaskets to fix the air leak.

February 12th, 2011, 03:25 AM	#4
johnjohn ninjette.org member Name: John Location: Caledonia, Ontario, Canada Join Date: Jul 2010 Motorcycle(s): Honda, Buell, Kawasaki, Suzuki, Yamaha Posts: 170	+1 on the leak.

February 12th, 2011, 12:35 PM	#9
kkim Join Date: Nov 2008 Posts: Too much.	so... did they remove the exhaust when it was there?

February 12th, 2011, 01:42 PM	#10
sombo Newb..... on a steeek! :D Name: Mike Location: Windermere, FL Join Date: Feb 2009 Motorcycle(s): 2012 Harley Davidson XL883L Sportster Superlow Posts: A lot.	Would have to. They tore the engine apart to do everything. You have to take the exhaust off just to change the oil with how the pipe is situated.

February 12th, 2011, 02:03 PM	#11
kkim Join Date: Nov 2008 Posts: Too much.	if I were you, I'd start looking/checking to see if there are any leaks in the exhaust system before assuming it's something else, unless they changed your jetting or modified your intake system. I always start w/ the easiest/most simple things first and move on to more involved theories/causes once the simple ones have been eliminated. don't make assumptions that can come back to bite you later... been there, done that. you mention they did carb tuning... what exactly did they do?

February 13th, 2011, 10:02 AM	#12
sombo Newb..... on a steeek! :D Name: Mike Location: Windermere, FL Join Date: Feb 2009 Motorcycle(s): 2012 Harley Davidson XL883L Sportster Superlow Posts: A lot.	Not sure what they did with the carbs, that's just it. The 2-1 pipes are one piece the whole way back. Like I said before, it never had a gasket and only one bolt for the last 11k with no exhaust leak. I've had an exhaust leak on other vehicles and it never created a popping on decel only, just made them a bit louder and raspier. This is on high-rev decel only, like small backfire popping you see when people first put on their aftermarket exhausts and before jetting.

February 13th, 2011, 12:18 PM	#13
DaBlue1 Long Time Rider Name: Blue Location: Charlotte, NC Join Date: Sep 2010 Motorcycle(s): 2009 Kawasaki Ninja 250R Posts: A lot.	Chances are the dealer, set everything by the service manual spec. Most will not tune the bike to aftermarket settings unless you tell them to.

February 17th, 2011, 07:12 PM	#15
sombo Newb..... on a steeek! :D Name: Mike Location: Windermere, FL Join Date: Feb 2009 Motorcycle(s): 2012 Harley Davidson XL883L Sportster Superlow Posts: A lot.	I apologize kkim, I think you were right after all. I was getting worse and also getting louder. I took a much closer look today at the exhaust after work (was sick the last day and a half so I didn't look then ) and I could see that the nut was coming loose. I couldn't do anything there cause I just didn't have the time or space to deal with it. When I got home I checked it again and sure enough the nut was completely gone. I called up the service department of the dealership and they were good about it. He didn't think they should have touched the exhaust but said to just bring it by and he would put it on no charge. Didn't have enough time to make it there before they closed so I will swing by after work tomorrow. So again, I apologize kkim, I should have just listened to the advice I was asking for. I just didn't think it would be that simple. I mean, I've had the exhaust off myself a few times and never allowed that to happen. I figured a professional service shop wouldn't make that mistake. I've also had 2 cars that had exhaust leaks and never gave popping sounds like that, just got loud. Not to mention that it never had a gasket and one broken bolt for 11k miles lol. Hey, I never said the bike (or its owner) was perfect.

February 17th, 2011, 08:22 PM	#16
kkim Join Date: Nov 2008 Posts: Too much.	Mike... just a fellow ninjette rider trying to help out. My advice was based on the fact that when I was switching around the exhausts on one of the 4 stroke dirt bikes about a year ago, I installed an aftermarket pipe and found out it didn't fit, put the stock pipe back on and had high rpm decel popping when I rode the bike while testing. I had not done anything else to the bike and it ran great before I played with the pipe. I went back and used a torque wrench on all the nut and bolts on the exhaust system and the popping went away. I had hand tightened the system together positive that I knew what was right. Needless to say, I always use a torque wrench now. Popping/backfiring can be caused by many things. My advice on checking the exhaust was because it was the easiest of the things to check. It may have not been the exhaust, in your case, but I always try to work from the easiest to the more complex solutions first. It has saved a lot of time and headaches over the years from just guessing. Glad you found the problem and I hope the bike is back running as well/better than it was before the popping started. Enjoy!

February 17th, 2011, 09:39 PM	#17
sombo Newb..... on a steeek! :D Name: Mike Location: Windermere, FL Join Date: Feb 2009 Motorcycle(s): 2012 Harley Davidson XL883L Sportster Superlow Posts: A lot.	I will find out tomorrow after work. I wonder if they got out the broken bolt at all. It broke on the first oil change when a friend was helping me. It broke while he was hand tightening it and not even cross-threaded. We were all confused at that point as we all witnessed it. He hadn't even brought up the wrench and the bolt popped. Yay for random metal fatigue I suppose. But it's been fine with just the one keeping tight till now. Hopefully this cures it cause holy crap is that annoying when it pops while decelerating or engine braking.

February 22nd, 2011, 07:53 PM	#18
sombo Newb..... on a steeek! :D Name: Mike Location: Windermere, FL Join Date: Feb 2009 Motorcycle(s): 2012 Harley Davidson XL883L Sportster Superlow Posts: A lot.	UPDATE Ok, so I took it back to the service shop that Friday after work. They took in and found out not only was the nut missing from one bolt and a bolt broken on the other side like I said, but there is so much corrosion on the bolts that there is more then one broken. They were able to make it work with running a secondary bolt and securing others. They said it's fine for now but I will need to get it taken care of eventually with them drilling out the broken one, and putting in all new hardware. They also showed me that one of my forks is starting to leak. It's just damp which they said is ok for now, but to not let it go for too long. He said he would get me an estimate on the work for them, but I haven't received one from them yet. They didn't charge me for the repairs to the exhaust and all the popping is gone. I also stopped by a different shop that I know does their own fork work (only one I could find in Orlando that does it seems) and got an estimate on getting them rebuilt and maybe even stiffened. If I get the racetech springs through them and have them do all the work it would be around $435 or so. The springs themselves through them would cost about $103 he said. I was also considering looking for some springs from a Ninja 500 as suggested by the other 250 site. I also need to find a good junction box cause mine is going bad (intermittently blows the headlight fuse if I use the high-beam, already had someone else diagnose it to that) and a new horn. The horn is just basically worn out and dead, so I want to replace it with a louder one. As you can see it's not a perfect bike, needs stuff here and there. But all in all I love my bike and will be doing my best to schedule in all this work it needs to make her run nice and smooth.

February 22nd, 2011, 08:04 PM	#19
kkim Join Date: Nov 2008 Posts: Too much.	Mike, do you want to do the fork work to upgrade the bike or are you doing it only because of the seal leak? what if there was a way to maybe fix the leaking fork seal w/o disassembling the forks?

February 23rd, 2011, 09:01 AM	#20
Cuongism ninjette.org certified postwhore Name: Cuong Location: San Diego Join Date: Jul 2010 Motorcycle(s): 2008 Ninja 250r, 2007 Daytona 675 Posts: A lot.	When my left fork was leaking, I just replaced the fork seals, dust wipers and put in heavier fork oil. I also steel wooled any bumps found on the forks. 6k miles later and still no more leak. Total cost was about $40 total for parts and then my own labor. If you're not looking to upgrade the suspension, I don't think you need new springs. Good luck with it though And Kelly, there's a way to stop a leak without disassembling the forks??

February 23rd, 2011, 10:18 AM	#21
sombo Newb..... on a steeek! :D Name: Mike Location: Windermere, FL Join Date: Feb 2009 Motorcycle(s): 2012 Harley Davidson XL883L Sportster Superlow Posts: A lot.	First, I don't have the tools, area, or knowhow to do it myself. Second, it's always been my plan to eventually upgrade the forks cause I want to lesson the front end dive. You have to realize they have 17k miles on them and I'm also around 200+ pounds, the front end tends to dive a bit lol. Also kkim I believe in doing the job right and not just throwing a bandaid on it. What the guy showed me is that to do the job right there are 3 other parts inside the forks you should replace besides the seals. The forks have 17k miles on them and need to be serviced fully imo.