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Discussion Starter #1
I am in the UK although the bike is still fitted with the US emissions reed valve system.

When I open my ears at the initial air intake there is a square rubber hose that bends at 90 degrees and ends just over the edge of the top of the filter element.

When I look in my 3 different manuals this part is not shown (what is shown is a simple square rubber grommet that just covers the square intake hole cut out of the back of the ear).

In all of the pictures I have seen of open ears I have only ever seen the simple square finishing grommet or just the bare square hole.

So, has anyone else seen the parts I'm talking about?

I was thinking that people might be removing them as they obviously cut down the airflow into the ear.

The part is definitely made for the bike but I was just interested as I've never seen them anywhere else and none of the manuals seem to show them.

Cheers, Trace.
 

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Have you checked the online manual here?
 

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Part information

Trace, I haven't seen that part before, but it sounds like you have a California/Switzerland model bike. The California/Switzerland bikes have some extra emissions parts. At the base of your fuel tank (under the lip of the seat) do you have two vents? If so, then you have the one of those models. That part is shown in the Clymers manual in diagram 75 on page 272, part number 15. It's labeled simply "Fitting (California and Switzerland only).

The manual on Ron Ayers site shows it as part # 92071A. Is that the part you're looking for? Take a look at the service manual page here (top left quadrant of pic, zoom in and it's inside a box):

http://fiche.ronayers.com/Index.cfm/Module/Main/TypeID/26/Type/Motorcycle/MakeID/3/Make/Kawasaki/YearID/27/Year/1986/ModelID/4193/Model/Vulcan_750/GroupID/132667/Group/Air_Cleaner(1/2)
 

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Discussion Starter #4
No the part I'm talking about is instead of #14703C on the main part of the ear.

Thanks for putting up the link it makes it a lot easier to explain what I'm talking about.

Cheers, Trace.
 

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Huh. Weird. I've never even heard of something like that then. Sorry Trace.

Bookmark that site though, those diagrams and part numbers come in real handy.
 

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Discussion Starter #6
Interesting, I took some measurements today and the unusual intake duct grommet/square rubber tubes on my bike cut down the air intake duct size by nearly exactly half.

I'm gonna take some pics of these so you can see them.

When I've got more time I'm gonna have to check the size of main jet in the carbs (removed the rubbers and definite fuel starvation when main jet takes over).

Bike goes like a train (I've seen just over 120mph on the speedo twice) but this is still an obvious air restriction (the parts are definitely made for the bike).

I find it interesting that with the many people that have viewed this thread and checking all the manuals and parts fiches I can find that nobody else seems to know about these parts.

Cheers, Trace.
 

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Hi Trace. If you are on the look out for standard parts let me know. I'm going to look at a scrap 750 and possibly a 700 at the weekend (my petrol cap got crow-barred) If the air filters are still with the bikes I could get a price for you. I'm in the UK so postage wouldn't be much.
 

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Discussion Starter #8
Hi Retro,

I maybe interested in both of the 750 wheels but don't need them, it would have to be at rock bottom price as there is absolutely NO demand here for them.

But if they want some cash with no hassle quick, then I may make an offer.

Cheers, Trace.
 

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I find it interesting that with the many people that have viewed this thread and checking all the manuals and parts fiches I can find that nobody else seems to know about these parts.

Cheers, Trace.


My guess, unless you bought the bike new, is that someone replaced the stock grommet with the odd one you found. Guessing there ie one on both airboxes?

You did not mention the year either, but Kawasaki does not substitute parts without making note of it somewhere.

KM
 

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didn't some of the euro models come with smaller main jets therefore the smaller air intake also .I am thinking out loud here all the intake rubber grommets going into the surge tank I have seen were oblong,Now I am confused that is the grommet we are looking at, correct? IGNORE THIS POST I WAS LOOKING AT THE WRONG END OF THE AIR FILTER HOUSING ,I really don't know I threw all that crap off mine in favor of K&N's Before I rode it.
 

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Discussion Starter #11
Here are some pics of the strange intake tubes, the tubes cut down the air intake hole size to 30 x 16mm.





Cheers, Trace.
 

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Yeah that's not a kawasaki part. Guess someone found those and thought they would somehow help the intake. The bad part is it directs in coming air to only one section of the air filter, which is a big design flaw...so that in itself tells me that in no way is it a Kawasaki installed part.

Just cut the "tube" section off and you'll be better off.

KM
 

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I found a comparable tube on the air intake of a Yamaha XV125 and thought that since it restricts the air flow I will remove it. I did and the bike ran like crap. I guess I should have changed the jets and jet needle of the carburetor too, but tuning a carburetor goes beyond my skills. So I put the tube back. :doh:
 

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Discussion Starter #14
I'm still convinced it is a part made for the bike (which is a '93) as it fits so perfectly.

Next I'm going to check serial numbers on the bike engine and frame to see what model it is and also check main jet sizes.

Cheers, Trace.
 

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Discussion Starter #15
It's definitely a european/general model (not that that makes anything any clearer).

I'm dying to find out the jet sizes now, they must be smaller than the standard 132's as the intake tube's block off half of the normal air intake hole size and the bike runs flawlessly.

I'm pretty sure there's a couple more horsepower can be had here without much work as the engine seems to only be drawing half of the air that the rest of you are.

I read here that you can get to the jets without taking the carbs off the bike but it doesn't look all that easy.

For those who have managed it is there any amount of fuel spillage when you take the bottom off the carb?

Cheers, Trace.
 

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Hi Retro,

I maybe interested in both of the 750 wheels but don't need them, it would have to be at rock bottom price as there is absolutely NO demand here for them.

But if they want some cash with no hassle quick, then I may make an offer.

Cheers, Trace.
Hi Trace. Tried to look at the 750 today but he's sold the whole bike. The 700 has no tank so I didn't bother making the journey. It's on flea bay at the moment if you want to check it out. I live about 20 miles from it, if you want anything looking at. Cheers. Gaz
 

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Discussion Starter #17
Hi Gaz,

Thanks for letting me know, I don't need the wheels so I'll just leave it.

Seeing as your also in the UK what year/model is your bike and does it have these tubes inside your ears?

Cheers, Trace.
 

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Hi Trace,
Mine's an 89, imported from the States at some point. It doesn't have the tubes in the ears.
What part of Scotland are you in? We've got a lot of family between Glasgow and Newcastle and spend a lot of time in the borders.
Cheers.
Gaz
 

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Discussion Starter #19
Hey Gaz,

I was born in Glasgow (and Newcastle is an adopted part of Scotland anyway) and know it well, we now live about 20miles south of the city in Troon (golfer's paradise, about 4miles from Prestwick airport).

Do you have the apparently standard grommets fitted and if you do could you tell me the size of the inlet hole in the ears? (amongst other things I'm a guitar tech. which is why I'm always interested in precise measurements).

Thanks for your time!

Cheers, Trace.
 

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A second look at the pic you posted started to ring a bell in my mind. And indeed, I have those tubes also! My bike is the -94 German version. Somehow I think that tube has something to do with the 37kW the bike gives, which is less than any other version of the bike (not counting the versions limited to 27kW).

If there is a simple way (remove the tubes, change the main jets) to improve the power, I would do that change too, but I won't start experimenting. So if you go ahead with this, please post the results.

My main jets are 110, the US version has 132. If I were to try out some other size, that would be the 132.

For those who have managed it is there any amount of fuel spillage when you take the bottom off the carb?
Drain the carbs before opening the bowls. There is a drain screw at the bottom.
 
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