Vaquero intake leaks

[RACNRAY]

OK...had time Tuesday to check my skoot for intake leaks. Mark removed my intake so we could do the spray test. I use Maxima Chain Gaurd to check for leaks due to it's viscosity and tendancy to stay where we spray it. It is white in color and if there is a leak i will see it get pulled into the leaky area and disappear. Not only was there leaks between the throttle body and manifold, but there are leaks between the manifold and intake ports on the heads. I ordered new o-rings for both areas.

I found a surprise when examining the throttle bodies. The flat surface where the o-rings sit on the t/b DOES NOT mate up against the manifold as should be. At each mounting bolt hole there are stand-offs that space the flat surface of the t/b's AWAY from the manifold. There is very little compression of the o-rings, which at this point on my bike they should have a flatness to them, and they don't. I will remove the t/b and machine these stand-offs to allow better sealing of the o-rings.

Where the manifold attaches to the head concerns me. The new o-rings are relatively thick, so unless there are machining irregularities that have to be corrected these new o-rings will be installed with Three Bond 1211 sealant.

Pics will be following.

RACNRAY

[RACNRAY]

For no reason popping and backfiring on decel started bout 2 months ago. A little bit at first, then got worse. The idle became unsteady, and the cold start high idle started to fluctuate. A bit of a hesitation off idle really started to annoy me. I had done nothing to the skoot and started to think about the forum member's thread about the intake leak.

PIC OF NOT QUITE FULL O-RING SEAL ON MANIFOLD...



AT MY FINGERTIPS ARE THE POSTS THAT PREVENT THE THROTTLE BODIES FROM SEALING AGAINST THE MANIFOLD SURFACE, 5 IN ALL...




GETTIN READY TO MACHINE OFF THE POSTS...



MACHINING...



THE THROTTLE BODY MATING SURFACE WAS NOT FLAT AND TRUE SO SOME FINAL BLOCK SANDING MADE IT STRAIGHT...


AFTER ABOUT 20 SECONDS OF SANDING THE INTAKE MANIFOLD, IT'S ALSO NOT STRAIGHT AND FLAT...



ABOUT 45 SECONDS MORE...



FINALLY, A FLAT SURFACE!!...



MORE TO COME...

RACNRAY

[RACNRAY]

A LOOKSIE INTO THE INTAKE MANIFOLD AFTER A TRIP TO MY PORTING AREA TO CLEAN UP THE MANIFOLD WALLS...





SEALANT ON THE INTAKE PORT SURFACES TO MINIMIZE VACUUM LEAKS THERE...



NEW O-RINGS AND MORE SEALANT ON THE MANIFOLD WHERE IT MATES TO THE HEADS...



AND A TRICK WE LEARNED YEARS AGO THAT I FORGOT TO DO IN MY EARLIER MODS....




This is a pic of the air temp sensor removed from the air box and relocated AWAY from any heat source. The wires are extended allowing the sensor to be located just behind the fairing, tied to the wiring harness. This stabilizes the temps the sensor is exposed to, and provides for more consistent F.I. performance.

I allowed the sealant to cure overnight and this is how this thing responds to these mods.

After letting the silly-cone cure over night i cranked up the skoot yesterday morning. The cold start high idle was much better. When the high idle system signed off it had a much more stable idle, and i could tell better throtttle response, with a bark i had not heard in a long time. It seems to have a deeper exhaust tone to it also.

Took the ride up to Ft. Lauderdale to pick up parts, so here are the first impressions.

The back fire on decel has been reduced about 25-30%, but most of all the big BANG i was gettin at 2000 rpm has been reduced quite a bit. I'm gonna check the packing in my muffler to see any has burned away. I was hoping for more of a reduction, but the performance improvements i noticed are what i had hoped for.

The low rpm/part throttle performance has not only been restored, but is a tad better than it ever was. The throttle response is immediate, and there is less throttle required to do what i want done. The throttle response had become lazy and, i guess i could say kinda fluffy. This had occured over many thousands of miles so it finally got my attention when i was just not as happy ridin this skoot, specially in the manner where that part throttle response was lacking. There is a deffinate improvement in acceleration up to 3000 rpm and maybe 20-30% throttle, exactly where i was not happy with how the skoot had been running.

It also has a much steadier idle, which aoccured along with the other complaints. Neat thing, the skoot also sounds better, tighter comes to mind. When passing cars on the hiway i don't have to twist the throttle as much, the engine does not feel as if it is laboring, especiall with the cruise control on ans going over overpasses.

I am gonna try to do some ridin tonite, don't know how much, so i may have more info tomorrow.


I did get to ride it last nite and the impressions i noticed on yesterday's short ride were backed up. The engine labors much less, low rpm/small throttle openings are much improved. The off-idle glitch is gone, throttle response is clean and right now.

I remember having to really twist the throttle more than i used before to pass cars on the hiway, now just a small twist of the throttle gets me what i want. The deterioration of performance happened over many miles but within a 2 or 2 1/2 month time frame.

It was worth the time to do this as i said i was becoming unhappy and irritated ridein this skoot with the problems. I am now back to being able to enjoy this skoot with the glitches gone.

RACNRAY

[cnc]

Interesting. Since the posts were probably there to prevent over flattening of the O rings and or excessive distortion of the mating surface, I'm wondering if perhaps it was designed to take a thicker O ring. The recess does look like it could accommodate a thicker one except maybe the little retainer tabs could be an issue.

[brote]

Is the Vaquero a "Closed Loop" system ? Moving the air temp sensor does help, I have done this with my Camaro.

[blowndodge]

Ray, had your MPG's starting falling off as well during the time in question?

[RACNRAY]

Originally Posted by brote

Is the Vaquero a "Closed Loop" system ? Moving the air temp sensor does help, I have done this with my Camaro.

No, the Vaquero is open loop.

Originally Posted by blowndodge

Ray, had your MPG's starting falling off as well during the time in question?

Yes, that was another indication that something was going awry. The mpg seems more consistant now, and does not fall of as drastically when pushing into a headwind or at hiway speeds above 75 mph.

RACNRAY

[jestephens]

Thanks for these posts.
I wonder if anyone at Kawasaki could help explain some of these issues. IMO, if this is common, a recall should be in order. Then again, there have been other things that should have been recalled on the past models (POG, clutch springs, etc)

Thanks again!

[replay13]

Thanks for the info Ray, I don't seem to have any problems with my Nomad and 17,000 miles, but at any sign of a air leak I'll check there first. I doubt I would get that kind of service at my dealer so I would fix it myself or take it to a machine shop for the posts.
Or maybe just try to find a thicker o-rings and sealer might be the way to go.

It looks like the o-rings set in a groove for them, so I take it you machined off the posts completely?

Thanks again for taking the time to post the pictures,
James

[blowndodge]

I had heard that the 1600 Nomads had that issue as well..that's why some of them pinged like pigs!?

[Top Cat]

Originally Posted by blowndodge

I had heard that the 1600 Nomads had that issue as well..that's why some of them pinged like pigs!?

Hey city boy, I have heard pigs oink, grunt and snort, but never heard of one pinging.

[ponch]

I'm guessing this voids the warranty...

[blowndodge]

Originally Posted by Top Cat

Hey city boy, I have heard pigs oink, grunt and snort, but never heard of one pinging.

Is this before or after you've dressed them in women's lingerie??

[cnc]

Originally Posted by Top Cat

Hey city boy, I have heard pigs oink, grunt and snort, but never heard of one pinging.

Sonar pigs?

[recumbentbob]

Originally Posted by blowndodge

Is this before or after you've dressed them in women's lingerie??

evolution