Carb Tuning/ Power loss - ZX Forums
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post #1 of 24 (permalink) Old 05-05-2017, 08:44 PM Thread Starter
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Thumbs down Carb Tuning/ Power loss

So i just recently got a 95 ZX7, As i was going to change the air filter , i had found that the previous owner had used a t shirt and old rag as the filter. After replacing them with a proper filter, the bike runs like shit now. I figured its because it is getting air unrestricted now. I adjusted the fuel air mixture screws to 2 1/2 turns out and the throttle response is great and sounds great. But now it has no power, It has no torque and feels like its gonna stall, Low range - high end RPMs. What could be causing this? Before i put a filter in it it ran alright. This is obviously some kind of Carb problem, But what would cause this behavior?
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post #2 of 24 (permalink) Old 05-06-2017, 07:24 AM Thread Starter
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post #3 of 24 (permalink) Old 05-06-2017, 12:01 PM
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Carb Tuning/ Power loss

Nice bike
Nothing like the dirty old tshirt trick.

Did u pull the carbs off?
Did u look at plugs?


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post #4 of 24 (permalink) Old 05-06-2017, 01:45 PM
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no expert here but it sounds like its now running lean
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post #5 of 24 (permalink) Old 05-06-2017, 07:11 PM Thread Starter
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Just put new NGK plugs in it. Not an expert on adjusting the carbs but id like to learn. Im not sure its running lean , but its very weird. Throttle response before was very laggy and shitty but it had good power all through out. After i put a filter and plugs in, i adjusted the mixture screw to compensate for the increased airflow, and now the throttle response is perfect. but it has no power. When you give it throttle it has very little torque and feels like its going to stall. Any ideas?
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post #6 of 24 (permalink) Old 05-06-2017, 10:08 PM
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set the mix back where it was, you really want to make sure its not too lean or the valves can have issues getting hot. hopefully one of the carb guys on here will advise, I'm sure someone has seen this before.

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post #7 of 24 (permalink) Old 05-06-2017, 10:38 PM Thread Starter
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set the mix back where it was, you really want to make sure its not too lean or the valves can have issues getting hot. hopefully one of the carb guys on here will advise, I'm sure someone has seen this before.
will do. I was thinking of taking them out and cleaning them, and checking the float height and needle settings to see if they are out of whack. but i dont have any experience doing so
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post #8 of 24 (permalink) Old 05-07-2017, 06:17 AM
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With using a t shirt for an air filter, you can count on the PO not cleaning the carbs or setting them up correctly. Get a manual, be organized and do it your self. You will learn how to do it hands on. It is not too difficult.
They will need a thorough cleaning and proper set up and sync to run properly.
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post #9 of 24 (permalink) Old 05-07-2017, 07:49 AM Thread Starter
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With using a t shirt for an air filter, you can count on the PO not cleaning the carbs or setting them up correctly. Get a manual, be organized and do it your self. You will learn how to do it hands on. It is not too difficult.
They will need a thorough cleaning and proper set up and sync to run properly.
Exactly my thoughts, only problem is i cannot find a manual for this bike.
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post #10 of 24 (permalink) Old 05-07-2017, 08:38 AM
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Manual will give you specs and standard jet sizes. If you take them apart, clean them and have questions, there is a vast knowledge on this forum for these bikes, someone will help. There are PDF manuals available as well, someone on here can probably direct you to one.
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post #11 of 24 (permalink) Old 05-07-2017, 08:44 AM
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Look at this on eBay:

https://www.ebay.com/itm/302263767834

Kawasaki OEM Service Manual Supplement 93-95 ZX750 ZXR750 ZX-7R 99924-1160-52


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post #12 of 24 (permalink) Old 05-07-2017, 08:46 AM
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http://motoservicemanual.com/kawasak...nual-download/




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post #13 of 24 (permalink) Old 05-07-2017, 08:50 AM
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Manual will give you specs and standard jet sizes. If you take them apart, clean them and have questions, there is a vast knowledge on this forum for these bikes, someone will help. There are PDF manuals available as well, someone on here can probably direct you to one.


I just did mine last month.
Never touched carbs before.
It was not hard at all and did get some great advice here for trouble shooting and dialing it in.

The bike runs way better now after that cleaning and some tweaking.


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post #14 of 24 (permalink) Old 05-07-2017, 09:29 AM Thread Starter
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I just did mine last month.
Never touched carbs before.
It was not hard at all and did get some great advice here for trouble shooting and dialing it in.

The bike runs way better now after that cleaning and some tweaking.


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Quote:
Originally Posted by keepitgreen View Post
http://motoservicemanual.com/kawasak...nual-download/




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Appreciate all the help guys, im gonna take it apart today and go through the cleaning and tuning to specs. ill repost on here afterwards.
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post #15 of 24 (permalink) Old 05-07-2017, 11:16 AM
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This thread might give you some help:

http://www.zxforums.com/forums/zx-7r...-database.html
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post #16 of 24 (permalink) Old 05-07-2017, 01:45 PM Thread Starter
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This thread might give you some help:

http://www.zxforums.com/forums/zx-7r...-database.html
Quote:
Originally Posted by keepitgreen View Post
I just did mine last month.
Never touched carbs before.
It was not hard at all and did get some great advice here for trouble shooting and dialing it in.

The bike runs way better now after that cleaning and some tweaking.


Sent from my new fangled morse code machine
--.. -..- --... .-.
Update: Took the carbs off. Seems to have the KLEEN air mod/ Float bowl mod done to it. Also , One of the vacuum lines is plugged and the other three have lines running out and are plugged at the end. Should i just take out the lines and plug them all? After reading about the mod on another forum, it seems like you can plug them. Im also going through the process of checking the needle height and float height at the moment

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post #17 of 24 (permalink) Old 05-07-2017, 02:04 PM Thread Starter
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The main jet is a size "128"... but in the manual for my bike (ZX750L) it says the main jet is a size 170 and 190
.
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post #18 of 24 (permalink) Old 05-07-2017, 06:51 PM Thread Starter
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what do you guys think? if the jet size is too small, will it cause the studdering and no power feeling?
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post #19 of 24 (permalink) Old 05-07-2017, 06:56 PM
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Those are Dynojet sizes. The numbers are different than OEM/ Keihin. PO likely installed a Dynojet kit. Check the database on this forum to see what DJ sizes people are running as well as their set up.
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post #20 of 24 (permalink) Old 05-07-2017, 07:05 PM Thread Starter
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Not sure. just checked the chart, no matter if they are mikuni, keihin, or dynojet, 128 is much smaller than the stock 170/190.. Im most likely going to just buy the stock jet sizes and see if it fixes it.
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