just got my carbs back from a rebuild. Pulled many years ago and life interfered in reassembly. Now that I have them back and they are installed I find that two nipples do not seem to have a home. When I removed them I do not recall there being any open tubes(as indicated by photos I find online) anywhere on the carbs. Where can I find an accurate map of the lines? the nipples in question are on #2 and #4 airbox side. to add to the mystery I seem to have 2 vins neck plate says kz650E004164, but engine stamp says kz650DE030541. Neither seem to be searchable online so I am unsure what model carbs I have. Any assistance is greatly appreciated
Welcome to KZRider! Caught ya at 2 posts!
Go to homepage, then Filebase. Search KZ650 without the E (no results) and dig. I'm no expert; Lemming.
Also, if exhaust recycle tubing is removed, there are nipples on the carbs that get covered. Ones on the bottom of bowls are overflow and drain on my CV34s. Pictures please.
Much appreciation for the greeting and the info. So those two tubes DO appear to be venting, just seems weird leaving them open to the world. Will capping exhaust recycling require any changes to carbs? or can I just cap them and be done with it?
Now I just need to get it to idle without choke on so I can balance them easily. Also that link for FSM is for 81 on, are they similar enough mechanically to be of use? The clymer I have only has an addendum at the back for 1980 and the changes they made. useful, but incomplete
The vent ports should have tubing on them to keep water out. Mine are routed over the airbox shoulders & fitted snugly between the airbox & side covers. The LH tubing has a tubing clamp guide clipped to the frame.
That's a nice and neat set up Ed but I'd be thinking about it disrupting the air flow.....( I'd sell my grandma for a half horse power)
I have always kept mine open to the wind but I agree routing the lines would be a better solution....... Just don't run en behind the motor down low with the bowl drains ..... I had some kind suction thing going on like it was stalling at speed the first time I put them there and it stopped as soon as I took em off....... a few others I remember saying the had the same thing happen..... kind of like when you get a super strong side ways wind with pods. (I know Ed Damn pods anyway)
1978 KZ650 b-2
700cc Wiseco kit 10 to 1.
1980 KZ750 cam, ape springs, stock clutch/ Barnett springs.
Vance and Hines Header w/ comp baffle and Ape pods, Dyna S and green coils, copper wires.
29MM smooth bores W/ 17.5 pilots, 0-6s and 117.5 main
16/42 gearing X ring chain and alum rear JT sprocket....
650ed wrote: Here's a picture of where the two vent tubes terminate on my KZ650-C1. Their ends terminate in the air filter opening. Ed
I've never seen a factory bike with vent tubes going into the intake mouth. That puts the vent tubes under changing pressures. I've always seen the factory tubes just open ended just after that plastic holder (baffle plate) for the tubes. Near the mouth of the intake or closer to the battery, but never inside of the intake.
Looking at the factory manual for the 77 Kz650, page 41 shows the vent tubes going past the air intake and to the battery box area. Page 42 says "Route the carburetor vent tubes (2) to the battery housing sides between the air cleaner housing and the baffle plate"... not exactly clear on what they mean, but it seems the hoses are meant to go to the battery box area.
When I was doing jetting tests, and was doing a fringe test on the lean side, just moving the vent tube out into rushing air was enough vacuum to cause a hesitation. I would think a similar issue would happen with having the tube in the mouth of the intake. Under normal jetting it might not hesitate, but will be slightly leaner than designed. More importantly, the amount of pressure will change with throttle. This will alter the bowl pressure with throttle. That introduces another variable that did not exist before. If the factory had intended for the bowls to be vented to intake mouth pressure, I think they would have created a hookup port on the filter holder of some sort.
I just try to route them into an area that will have still air, but not in a sealed off area. Near the battery box or up under the tank is usually good.
loudhvx wrote: ............ I've never seen a factory bike with vent tubes going into the intake mouth.
That's how mine has been since I bought the bike new in very early 1977. In over 43 years it has never caused me any trouble at all. In looking at the way the baffle is shaped it appears that it was intended to have the tubes routed this way. I say that because both bottom ends of the baffle have semi-circles shaped into them that actually hold the vent tubes in place. Ed
The Kz550 baffle plate is the same with those little cutouts, but the tubes just sit straight out on either side of the top of the airbox. Maybe it was the dealer who prepped the bike with the tubes going into the intake mouth?
loudhvx wrote: The Kz550 baffle plate is the same with those little cutouts, but the tubes just sit straight out on either side of the top of the airbox. Maybe it was the dealer who prepped the bike with the tubes going into the intake mouth?[/quote