Intake Leak

[BC RED VAQ]

I have a 2011 vaquero after buying it I put V&H slipons on it and a cobraFi2000r. My third mod was the thunder air kit for the stock air covers. I could never get it to stop popping and backfireing on decel I was at a dealer one day talking to the machinac. He said leave it with him a couple of days and he would check it out. The next day he called me and told me I had a leak between the throttle body and intake. I told him about people on the forum having the same problem and kaw would not do a recall. He said he would fix it for me where it would never leak again.

After a week or so I was getting more popping and backfireing again I tried to tune it out with the cobra. But more or less fuel was not making no difference in the decel noise. I let it go for awhile thinking I could get use to it But monday I took off the throttle body and found the machinac only put new orings in it, some fix. I ordered new orings the thunder gasget and went to the bike shop and got the best high temp gasget sealer they had. I cleaned the intake with alcohal and put gasget sealer on the intake with a small wide paint brush. Then I pushed the gasget on the intake and cleaned the ports of any sealer. After waiting 24hours I took a small paint brush and put gasget sealer in the oring croves and put the orings in. Then I took the wider brush and put gasget sealer on the outside of the gasget and mounted the throttle body to the intake. After torking the bolts and puting everything back together I waited 24hours. When I fired up the bike the ideal was alot i mean alot smother and it took half as long to ideal down and was smoth as glass the bike even sounded better and had better throttle responce. It runs better than it did when it was new. Sorry for the rant just wanted to tell my story maybe it will help someone else that can't afford the labor and mill work to get theirs fixed.

[crazygene49]

Glad to hear you got it fixed. Too bad the guys at the shops don't know more.

[Old Bear]

Actually good detailed guidance there. I haven't had to do that on mine yet, just a matter of time from what I'm seeing on here.

[RACNRAY]

The Thunder gasket is a good thing, saves lotsa time and money, the way to go to get rid of the leak between the t/b and manifold.

RACNRAY

[smokey]

I think some amplification is needed here, not all 1700s have the so called intake leak, popping on decel is not always caused by a leak, mine was caused by the design of the tri ovals, Cobra will even admit to it if you push them hard enough, it can also be amplified by the installation of the hypercharger, according to one mechanic I talked to. I did do the gasket and noticed no difference at all. I switched to a PCV and have virtually eliminated the popping because I had the bike dynoed and the right map is now installed.

If you have an intake leak there could also be a problem that the three bolts holding the plate may not have been tightened in sequence, IMO it is a poor design to have three bolts when there should have been four. There is also the possibility that the rubber o-ring may have come out of the groove during installation and allowing air in.

You will notice that all popping gets worse when an aftermarket exhaust and air kit is installed, so there must be something to say for that aspect as well.

[RACNRAY]

Intake leaks are just one source of popping on decel. On my skoot the loss in mpg, idle
instability and the hesitation at small throttle openings were the most obvious telltale sogns of a vacuum leak. Even the smallest of leaks will detract form the running performance to some degree.
The 1700 Vulcans are not alone in the decel popping, the VTX1800'S could be purty darn loud unless proper measure were taken.

RACNRAY

[smokey]

Originally Posted by RACNRAY

Intake leaks are just one source of popping on decel. On my skoot the loss in mpg, idle
instability and the hesitation at small throttle openings were the most obvious telltale sogns of a vacuum leak. Even the smallest of leaks will detract form the running performance to some degree.
The 1700 Vulcans are not alone in the decel popping, the VTX1800'S could be purty darn loud unless proper measure were taken.

RACNRAY

Instability and hesitation can also be a sign of improper settings in the ECU for the roll off idle, or the pilot jet/idle jet in carbs. Then there is the cable slack which sometimes affects it.

[galax83061]

Does anyone have the web site for the Thunder gasket? I am about to get exhaust and I guess I should probably do that.

[BC RED VAQ]

Just serch thunder air and go to the web site it is listed there thats how I found it Im not sure how to post a link or I would sorry.

[galax83061]

is this the one? http://www.thundermfg.com/store/inde...t_detail&p=472

[RACNRAY]

Originally Posted by smokey

Instability and hesitation can also be a sign of improper settings in the ECU for the roll off idle, or the pilot jet/idle jet in carbs. Then there is the cable slack which sometimes affects it.

This thread is about the intake leaks that have been found by many Vulcan owners and the process and materials needed to rectify this situation. The OP commented about how much better the skoot runs with the leaks fixed, so it is obvious that on his skoot the leaks were the source of hi performance problems.

No doubt there are many factors that affect the performance and running characteristics of any engine, but this thread is about intake leaks and how a forum member rectified those leaks and the results. Not all Vulcans have intake leaks and my skoot did not exhibit the signs of leaks till it was about 6 months old with about 10,000 miles on it.

RACNRAY

[BC RED VAQ]

My next mod is to get the pcv/ign and have it installed just to help the bike run better. what I did to the intake made a noticable difference in the way my bike runs now. I have the throttle mod and was having a hessation before i did the intake work. It is gone now I don't know about all the other stuff but it did improve how my bike runs thats all I know.

[smokey]

Originally Posted by RACNRAY

This thread is about the intake leaks that have been found by many Vulcan owners and the process and materials needed to rectify this situation. The OP commented about how much better the skoot runs with the leaks fixed, so it is obvious that on his skoot the leaks were the source of hi performance problems.

No doubt there are many factors that affect the performance and running characteristics of any engine, but this thread is about intake leaks and how a forum member rectified those leaks and the results. Not all Vulcans have intake leaks and my skoot did not exhibit the signs of leaks till it was about 6 months old with about 10,000 miles on it.

RACNRAY

I know what it was about, thanks though for pointing it out. I was responding to your comments.

[AZ Voyager]

Daniel... Yes that is the one. Have it on mine and it helped greatly

[jp58]

Originally Posted by galax83061

is this the one? http://www.thundermfg.com/store/inde...t_detail&p=472

Yes that is the part. Just make sure you put it behind the trottle body plate. Where the orings are. Not in front. Someone did that already.