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Discussion Starter #1
well, after about 3 months of riding, i finally found out i have had a air leak from the rubber gasket at the air intake manifold. i always wondered why i hading small backfiring even after i plugged the clean air switching valve. And i wondered why i didn't really notice a difference in performance with my fi2000.
i followed this procedure in checking for an air leak from this site on the Internet. all i did was remove the left side air box to gain access to the air intake manifold and throttle body assembly. then i took some contact cleaner with the small spray straw and while the bike was running, spray the cleaner on the connections and sure enough what they said would happen if i had a leak, happened. the bike idled down and almost died meaning the cleaner gained access into the intake.
this , i hope, is covered by the warranty. i like fixing things on my bike but this pisses me off so im not spending a dime on it. i just hope by running like this it didnt lean out my air fuel so much that it has harmed my pistons or rings. anyone with these symptoms can do this check.
 

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Sorry, to hear about your air leak. I also have the popping even after I capped off that line and with my fuel processor didn't really feel a big difference so, I guess I need to do the air leak test. I did a forum search and couldn't find the procedure so, if you could please let me know what the title or heading is so I can pull it up or is what you said in the post all there is to it. Thanks
 

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Thanks for that info Justin. Be performing the same test on mine tomorrow after work. Football on now! I too have a loss of performance and backfire with the same after mkt set up. I am planning a long ride this wkend and dont need this crap but if there is a problem thats just another place to look. Thanks again.
 

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Discussion Starter #5
If you're idle acts erratic after you let off the throttle when coming to a stop, like it takes a long time to go back to normal or it jumps up to 2000 rpms for no reason. When your bike starts rough during warmup. These are possible signs, along with backfiring , of an intake air leak. All I know is when I get to the dealer and after they look at the bike and they tell me there's no leak, I'm going to be pissed. It only makes sense that if there wasn't a leak, when I spray the cleaner on the connections , the idle would stay normal. There is a leak somewhere ifnot on the intake manifold gasket, it's on the fuel injectors or behind the throttle body, somewhere to make the bike die. I also made sure I didn't spray it in the right side filter box hole. Although I was concerned about what I could put over that hole while the Ike was running so dirt wouldn't get in. I used a lint free cloth and put a rubberband around the hole to hold it from sucking in. Just make sure the bike is warmed up first so you don't have to wait for the idle down period.
 

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If you're idle acts erratic after you let off the throttle when coming to a stop, like it takes a long time to go back to normal or it jumps up to 2000 rpms for no reason. When your bike starts rough during warmup. These are possible signs, along with backfiring , of an intake air leak. All I know is when I get to the dealer and after they look at the bike and they tell me there's no leak, I'm going to be pissed. It only makes sense that if there wasn't a leak, when I spray the cleaner on the connections , the idle would stay normal. There is a leak somewhere ifnot on the intake manifold gasket, it's on the fuel injectors or behind the throttle body, somewhere to make the bike die. I also made sure I didn't spray it in the right side filter box hole. Although I was concerned about what I could put over that hole while the Ike was running so dirt wouldn't get in. I used a lint free cloth and put a rubberband around the hole to hold it from sucking in. Just make sure the bike is warmed up first so you don't have to wait for the idle down period.
Justin ,You may want to pick Racirays brain on this subject. I would like to hear what he has to say. There may be an easy fix for you like tightening some bolts or screws or something. If you take it to the dealer ,please post there findings. so far I think i'm in good shape but that doesnt mean things wont loosen up in the future.
 

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Discussion Starter #7
Justin ,You may want to pick Racirays brain on this subject. I would like to hear what he has to say. There may be an easy fix for you like tightening some bolts or screws or something. If you take it to the dealer ,please post there findings. so far I think i'm in good shape but that doesnt mean things wont loosen up in the future.
Yeah, I wish he would chime in On this, I've talked to several mechanics and they have heard of this method of checking for leaks but they used eather. They said if it affect the idle, then it's getting through the seals
 

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Yeah, I wish he would chime in On this, I've talked to several mechanics and they have heard of this method of checking for leaks but they used eather. They said if it affect the idle, then it's getting through the seals
Justin I just looked at the VV service manuel and there appears to be a flange type gsket at the manifold to jugs that my need replace. doesnt look to difficult to check and see if the bolts are in loose. If they are tight than possibly the flange gasket may have not been installed properly creating the leak and would require replacement. If you dont want to tackle it then I would go to the dealer. There is no way of really knowing with out removal & inspection. The ether test would only verify seepage. Good luck. Keep us posted.
 

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Discussion Starter #9
Justin I just looked at the VV service manuel and there appears to be a flange type gsket at the manifold to jugs that my need replace. doesnt look to difficult to check and see if the bolts are in loose. If they are tight than possibly the flange gasket may have not been installed properly creating the leak and would require replacement. If you dont want to tackle it then I would go to the dealer. There is no way of really knowing with out removal & inspection. The ether test would only verify seepage. Good luck. Keep us posted.
Yeah, Ive heard that they are making thos gaskets out of cheap material to keep production cost down and due to the severe heat that these and all newer v twins produce, they deteriorate easier then the older style gaskets. My dealer doesn't open until tomorrow so I have to wait. Thanks, and I will
 

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Yeah, Ive heard that they are making thos gaskets out of cheap material to keep production cost down and due to the severe heat that these and all newer v twins produce, they deteriorate easier then the older style gaskets. My dealer doesn't open until tomorrow so I have to wait. Thanks, and I will
Just checkin to see how you are makin out? Keep us posted.
 

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Discussion Starter #11
Just checkin to see how you are makin out? Keep us posted.
still haven't hear anything back from the dealer, they have had my bike since Wednesday. i imagine they are waiting for the parts to come in. after you pull off the throttle body, the injectors and the inlet manifold, they require all new o rings and dust seals. so now they are closed till Tuesday so ill call them then.
 

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Discussion Starter #12
well i talked to the dealer today. the first things they said is there waiting on some parts to come in and i said" yeah, the inlet manifold seal" and their like "no, a new ecu". i asked how they came about that and what about my test i did on it and why would it die when i sprayed the cleaner on the manifold seal. they couldn't give me a straight answer. some hogwash about sensors. anyway they took a new ecu out of the floor model and put it in my bike and they said it corrected the backfiring i was getting and it ran perfect. they also said the ecu is on back order so they dont know how long its going to be before they get it. frikin great!!! i still dont get why it would bog down when i did that and them say its not a leak.
 

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Sounds like a leak to me. When you go to pickup the bike bring some carb cleaner with you and try the leak test again in front of the dealer.
 

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Discussion Starter #14
Sounds like a leak to me. When you go to pickup the bike bring some carb cleaner with you and try the leak test again in front of the dealer.
you know, it seems like all these dealers want to do is throw ecu's at the problem when there's ultimately other problems wrong with these things.
ill have to take off the left side air box or lift the tank but i will demand a better explanation as to why my bike would do that.
 

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No leak here - glad I checked :)

I have an 09 Nomad that I was doing a coolant change as it was a nice day up here in NH. I have been getting paranoid about the leak as I have a few of the power related symptoms. Pulled the covers and used contact cleaner to check for the leak. No change at all in the idle when spraying around the throttle body and intake areas; and when I gave a small shot in the intake in almost died. So no leak confirmed! :D

It was worth the 45 minutes to have the piece of mind!

Bob
 

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Hey Justin. My name is Tim from Pittsburgh PA. I had experienced the same problems as you with my 1700 Classic and found that I too had an intake leak. Ive been talking to RacnRay for quite a while and after he posted his findings on his bike I realized I was having the same problems with mine. But after taking mine apart I actually found mine to be worse than his. Not only were the seals between the intake and the heads leaking but the throttle body wasnt sitting flat on the intake causing a leak due to these stand-offs around the bolt holes that were actually taller that the ones on Rays throttle body. The intake to head seals on mine actually had small tears in them . I had to machine my throttle body to make it flat because there are stand-offs on the sealing surface that does not allow it to make complete contact with the intake manifold. After machining the stand-offs away the throttle body was still 7 thou warped. The intake itself was also warped and that surface had to be trued up as well. I reassembled everything with new seals and some sealer that Ray had recommended using on the intake seals it runs like a champ. I have had issues with the way my bike ran since i bought it and Kawi didnt really care. It actually seemed to run a little worse after the ECU replacement so I believe i had an intake leak all along. I have a full exhaust, programmer, intake on my bike and experienced decel popping ever since i installed the things. After this fix the popping has decreased by atleast 50 percent.
 

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Intake leaks and my cure

Here is the link to my thread detailing what i did to cure ALL of the intake leaks on my skoot. The design of the intake system laves much to be desired as far as a vacuum leak free system.

http://www.vulcanforums.com/forums/showthread.php?t=21798&highlight=VAQUERO+INTAKE+LEAKS

Since this modification the skoot has been running flawless, especially after i made changes to the map. The last time the skoot was on my dyno for mapping to the V&H 2-1 exhaust, it had some percenatge of vacuum leaks. Now with no leaks that map proved too rich, and i have achieved better performance and mpg with some revisions.

As soon as i have time i'm gonna throw it back on the dyno for a final
remap.

RACNRAY
 

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well i talked to the dealer today. the first things they said is there waiting on some parts to come in and i said" yeah, the inlet manifold seal" and their like "no, a new ecu". i asked how they came about that and what about my test i did on it and why would it die when i sprayed the cleaner on the manifold seal. they couldn't give me a straight answer. some hogwash about sensors. anyway they took a new ecu out of the floor model and put it in my bike and they said it corrected the backfiring i was getting and it ran perfect. they also said the ecu is on back order so they dont know how long its going to be before they get it. frikin great!!! i still dont get why it would bog down when i did that and them say its not a leak.
I got the same story, and an ECU change. Did not make any difference. I got tired of fighting with the dealer and removed the throttle body myself. I did not go as far as RacnRay and machine down the standoffs. Instead I removed the throttle body replaced the o-ring seals and used a tube of gasket sealer on both the throttle body and the intake manifold and re assembled. The improvement gained by this procedure is beyond what I expected. The bike sounds better, is running better and the back firing that almost turned me into a serial killer is 98% gone. I was at a point where I was not enjoying riding this bike due to the backfiring. I can honestly say the time I spent was worth the effort. My Vaquero is fun to ride again.
Seems to me that there have been enough people on this forum alone that prove, the 1700 engine (at least the last few years) has a major engineering flaw, and should be addressed by Kawasaki.
 

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I got the same story, and an ECU change. Did not make any difference. I got tired of fighting with the dealer and removed the throttle body myself. I did not go as far as RacnRay and machine down the standoffs. Instead I removed the throttle body replaced the o-ring seals and used a tube of gasket sealer on both the throttle body and the intake manifold and re assembled. The improvement gained by this procedure is beyond what I expected. The bike sounds better, is running better and the back firing that almost turned me into a serial killer is 98% gone. I was at a point where I was not enjoying riding this bike due to the backfiring. I can honestly say the time I spent was worth the effort. My Vaquero is fun to ride again.
Seems to me that there have been enough people on this forum alone that prove, the 1700 engine (at least the last few years) has a major engineering flaw, and should be addressed by Kawasaki.
You know, I wondered if a person could just use a high temp gasket sealer. I thank you for confirming that it will work. You can't really see it when all put back together I would guess. I also wonder if a gasket could be cut to go around the standoffs. In other words, to take up the space that the standoffs create and to compensate for the warping in the flat surfaces. I haven't had mine apart, so I'm only guessing about the gasket thing as being a possibility. I'm sure when Kawasaki finely gets the big idea that they do have a flaw in the design, their fix will not be to machine the standoffs down. That would be far too costly, it will be a cheaper fix like a gasket or something of the like.
 
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