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Slides at Part Throttle, KZ440
- bobrpm
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It's a 1980 KZ440 with 15,750 miles. The stock air filter is missing, but the air box is there. I fabricated a filter setup that uses 7/8" ID breather filters.
The left plug is white, the right is dark. I have observed the slides through the air box with the filters off, and they will snap up when I open the throttle wide open. Today, I noticed the slide doesn't move at part throttle, 4,000-6,000 RPM. It seems like it should move some at this throttle position to allow more fuel into the mix. Am I wrong? Should the slides only move at wide open throttle? I'm thinking this is my problem, but I'm sure that your knowledge and experience will help me verify this or I'll look for something else causing this.
Also, I know I need to replace the intake boots/carb mounts. I don't expect that to fix the cruising surging issue altogether, but it might help. Maybe I'll get lucky, though, and that will solve it. Thanks in advance.
-Bob
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- 650ed
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bobrpm wrote: ...............The stock air filter is missing, but the air box is there. I fabricated a filter setup that uses 7/8" ID breather filters....
IMO you are wasting time fiddling with it any further until you install the stock air filter in the air box. Home made stuff is not the same. After the stock filter is installed you can much more easily identify the problem IF a problem still exists. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- martin_csr
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Note: treat the airbox with care, especially the cap. Don't overtighten the screws or force anything. Also, on at least one of the airboxes, it's possible to install the cap wrong. If not done properly, this causes a vacuum leak. The test is to pull up gently on the back of the cap. it shouldn't move. (info from Andy-the-gringo).
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- bobrpm
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-Bob
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- bobrpm
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-Bob
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- Nebr_Rex
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.
2002 ZRX1200R
81 GPz1100
79 KZ1000st daily ride
79 KZ1000mk2 prodject
78 KZ650sr
78 KZ650b
81 KZ750e
80 KZ750ltd
77 KZ400/440 cafe project
76 KZ400/440 Fuel Injected
www.dotheton.com/forum/index.php?topic=39120.0
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- bobrpm
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- 650ed
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1. Soak them bolts with Kroil for 3 days prior to trying to remove them. I did this on mine and they came out with no struggle at all. Kriol will break the bond between the bolts and the cylinder head. Believe it or not, some folks have actually broken teh cylinder head trying to remove carb holder bolts that have bonded to the head. I re-applied Kroil each day for 3 days and the bolts easily came out.
2. Assuming they are the original bolts you need to understand that they are NOT Phillips heads even though that's what they look like. They are Japanese Industrial Standard (JIS) and using a Phillips screwdriver with deform the crossheads and will very likely make them nearly impossible to remove. Take a look at the following 2 links for details about how to make JIS screwdriver tips. Ed
www.kzrider.com/forum/search?query=newbi...0/2017&childforums=1
www.kzrider.com/forum/search?query=homem...0/2017&childforums=1
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- bobrpm
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Update: I got the new mounts installed. Didn't make any difference, but the old ones were definitely bad, so no loss. I realized that I cleaned the main and needle jets and passages but not the pilots, so I cleaned them out. Thought maybe they were flowing enough for a smooth idle but not enough for the transition from the idle circuit to the main circuit. No dice!
I narrowed the problem down to the right cylinder based on exhaust temps. Spark showed well at various RPM on both cylinders. I switched the the wires, then the plugs. The problem stayed with the right cylinder. Fearing the worst, I did a compression test. Both cylinders pushed 165psi. Awesome!
At this point I'm thinking I'm going for the mikuni single carb setup. I just want to be certain it's the carbs before I go that route. So, I observed the carbs through the air box with a flashlight.... again. Gas was flowing from the needle jet in the left carb and flying out on the right carb. That's when I realized that the right carb is missing the silver cylindrical thing that the needle goes into. Hmmm. Got one coming for $12 on eBay. I bet this part will meter the fuel coming from the needle circuit and my problem will be solved. Should know this weekend. Thanks again.
-Bob
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- bobrpm
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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