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89 zx10 squeek/chirp from exhaust


Shawn89

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Not sure if this is supposed to be here or in the daily ride section but here goes:

 

So I noticed a squeek/chirp from the exhaust the other day while riding. Thought maybe the baffle in my muffler was loose. So I took it apart and ran with no baffle. Still have the noise. Checked all mounting and nothing is rubbing anything. Even took the mid pipe of and ran straight header and the noise was super loud.

 

Question is, does anyone know what it might be?

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I just popped the carbs off. They seem to be slightly out of sync. Also checked the jet size and for a bike with a drop in filter and full exhaust with no baffle it has #137.5 jets in it. Isn't that a little small?
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It's coming from the exhaust for sure. I'm going to pull the valve cover as soon as I get a chance and see what's going on under there.

 

As for the jets I only know of one way to calculate the size but with a 38mm carb an open and filter is need something around a 180?

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As for the jets I only know of one way to calculate the size but with a 38mm carb an open and filter is need something around a 180?

 

What way is that?

 

180 is like Harley territory. No way your carbs are 38mm unless someone swapped them for some way too big racing carbs.

 

You measure carbs from the side that faces the head, not the airbox side. And you measure the inside diameter. Your year zx10 has CV carbs which means the airbox bell mouth on the carb is way larger than the actual intake to accommodate the vacuum ports that raise the slides. It's also oval shaped.

 

137 seems awfully rich. Pull your plugs and read them. What do they tell you?

 

The squeak could be carbon buildup if you are running way rich.

 

By the way the noise is not coming "from" the exhaust, it's coming "out" the exhaust. The exhaust only has one moving part: the exhaust gas. If the origin of the noise was the exhaust it would be a whistle from an exhaust leak. The noise is likely coming from inside your engine.

 

When was the last time you had your timing chain tensioner checked?

 

Also, and I know this was a problem for the 86-87 but don't know if it is an issue for the 1988-90, the starter chain runs next to the clutch and when the chain slackened over time the pressure plate would hit it and chew itself up. Sounds like a squeaky lathe running in your engine. Again I had to do a whole new starter chain for my dad's 86, don't know if the fixed it for 1988-90.

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The way I was showed was take the carb mm(38mm is what I seen as stock on the searches I've done) X that by 5 X say .95 for anything with a free flowing exhaust and air filter. So itll be 38x5x.95=180.5. Maybe this is the wrong way of doing it Idk.

I guess I'll be pulling the side cover and checking the chains to. I have a spare engine but it's in pieces.

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The way I was showed was take the carb mm(38mm is what I seen as stock on the searches I've done) X that by 5 X say .95 for anything with a free flowing exhaust and air filter. So itll be 38x5x.95=180.5. Maybe this is the wrong way of doing it Idk.

I guess I'll be pulling the side cover and checking the chains to. I have a spare engine but it's in pieces.

 

that formula works ok for linkage carbs on single cyl or twin cylinder engines. I've never seen it work all that well for bikes that use constant velocity carbs because, and this is esp true for sport bikes, the carb adjusts to engine vacuum. They are sometimes over-sized to compensate with the flow demands at high rpms and WOT since most of the rev range you'll probably not be using the full flow capacity of the carb (the slide won't be fully open). Honda put 130 jets in there stock for a reason, and while it may be slightly lean for emissions purposes, 137.5 probably fixes that.

 

By the way, I'll let you in on a little secret: bikes are not cars. There aren't nearly the restrictions in the factory pieces that people think. Most of the time you aren't "adding" hp with aftermarket parts so much as moving the power curve around at the cost of mid range driveability and adding noise. sure a freer flowing fliter helps, but it doesn't make the drastic change like you would see in a car.

 

Your plugs should tell the tale though. What do they look like? rich? lean?

 

By the way, how did you tell your carbs were slightly out of sync with the rack off? were the mechanical butterflies not opening at the same time? The slides you can see in front are raised and lowered by vacuum pressure - the way to test them is with a carb sync tool (4 vacuum gauges on a rack).

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When I took the carbs off I opend up the butterfly's and one or two was not open all the way. I do know this. The bike lost allot of power last time I laid into it. I couldn't get by a guy I work with who has a Harley bagger....... It felt like I was riding a 500 or something.
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When I took the carbs off I opend up the butterfly's and one or two was not open all the way. I do know this. The bike lost allot of power last time I laid into it. I couldn't get by a guy I work with who has a Harley bagger....... It felt like I was riding a 500 or something.

 

the butteflys out of alignment would def cause a sync issue. I believe they are adjustable. When in doubt get them all synched and then reset the sync with a carb vacumm gauge tool. While they are off I would have a look at the pilot and main jets to make sure they are not clogged and the slides to make sure they are not binding in the bores.

 

but now you are diagnosing a different issue here. Down on power, squeaking noise, all pieces to the puzzle. might be related, might be two separate issues.

 

Start with the basics. Do a compression test, leak down test, check the timing. In addition take the header off and shine a light into the port and see if you see anything wrong with the valve, and now that your carbs are off look down the port there as well. If you have the ability put a borescope into the plug hole and see what the valves look like.

 

Just looking up common issues with that gen of zx10, the clutch coming into contact with a chain tensioner is a common problem. might be you caught some of the warning sings (squeaking) before the clutch basket gets worn through and fails. good info in this thread:

http://kawasakiworld.com/zx-11/52894-1989-zx10-ka-boom-clutch-basket-alt-tensioner-chain-problems.html

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the butteflys out of alignment would def cause a sync issue. I believe they are adjustable. When in doubt get them all synched and then reset the sync with a carb vacumm gauge tool. While they are off I would have a look at the pilot and main jets to make sure they are not clogged and the slides to make sure they are not binding in the bores.

 

but now you are diagnosing a different issue here. Down on power, squeaking noise, all pieces to the puzzle. might be related, might be two separate issues.

 

Start with the basics. Do a compression test, leak down test, check the timing. In addition take the header off and shine a light into the port and see if you see anything wrong with the valve, and now that your carbs are off look down the port there as well. If you have the ability put a borescope into the plug hole and see what the valves look like.

 

Just looking up common issues with that gen of zx10, the clutch coming into contact with a chain tensioner is a common problem. might be you caught some of the warning sings (squeaking) before the clutch basket gets worn through and fails. good info in this thread:

http://kawasakiworld.com/zx-11/52894-1989-zx10-ka-boom-clutch-basket-alt-tensioner-chain-problems.html

 

Good read.

Hopefully tonight I'll get to pull the clutch cover and valve cover and see what's going on there. As for the carbs I may just try to find someone that can tune them up for me to my exhaust and filter. I don't have the vacuum gauge tool. The slides all move freely and smooth.

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Side cover is off. Here is what I've got

http://images.tapatalk-cdn.com/15/06/25/c63e76136a82aecc3c818df11c3dd9c1.jpghttp://images.tapatalk-cdn.com/15/06/25/a5d4b48c5f245344494505e2e35ec1a6.jpghttp://images.tapatalk-cdn.com/15/06/25/6e8a931fb3ca3ef71892756efc58aa51.jpg

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Yeah I don't see anything there. I did take the valves cover off and while doing so found a few possible vacuum leaks. Valves don't seem out of adjustment. I haven't checked with a feeler gauge yet but just feeling then it seems OK. I think while it's down this far in going to go ahead and do the head gasket and exhaust gaskets. Now just to find someone to tune the carbs.
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if you are going to "find someone to do the carbs" you might as well find them to do the valve adjustment. IIRC these are bucket and shim which is a pain in that you have to buy a bunch of shims.

 

did you look at your cam chain tensioner? should be on the left side and visible down the tunnel with the valve cover off.

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