Reed valve breathers

I have got to say, I love this place. I just posted a simple question about the reed valve breathers and I have been blessed with an abundance of really good, interesting, and useful info. Thanks guys, please... carry on!!

sometimes we get carried away:P

I have an 82 kz750, and also wanted information on this issue. Most of it has been answered, except I still am unclear on some things. I removed the emissions deal because it was annoying. I ran a hose between each reed valve deal. I was then informed that you must plug the vacuum holes on the carbs. I just cut up the tube into sections and screwed a bolt into one end for use as plugs. But the petcock is vacuum operated also. Does this need to be plugged? Do you need to run it on prime? I took my bike for a spin yesterday(finally got above freezing, about 40 degrees). Didnt seem to run like before. Even after warmed up, throttle was slow to react, and after letting off the throttle it stayed at that rpm for about a second after. Could this be because I didnt plug the carb ports 100%? Before I put the plugs on, I could blow in them and some air escaped but not alot.

Post edited by: jordan, at: 2008/02/25 23:29

You should leave a vacume line to your petcock so you dont have to run your bike on prime all the time.

Mr. 77kz750, I am like a sponge for the wealth of information that is offered. Please get carried away!!!

77KZ650 wrote:

i didnt notice any backfires, but my reed valves are circa 2001:P
every little bit of power gain is nice when you are racing, plus it makes the ram air more effective on a 12r with the air box(frame) sealed.
im pretty sure a vaccum on the crank case also helps because it makes the air thinner, when a crank is spinning through "thick" air it hurts power. why do you think people get their cranks polished? it makes them more "slippery" through the air and oil.
as an example my uncles drag vette (548ci big block) picked up something like 30 hp when he swapped to a deep sump oil pan. the crank doesnt have to turn thru oil. the less stuff the cank has to turn through the more power you make. even air holds you back when something is turning a few thousand rpm. he vents his motor to the exhaust, and has thought about putting a vac system on it. i think he was quoted on a gain of about 15hp with a really good vac system

a windage tray will keep the oil away from crank on car motor anyway,the vacuam affect of running from valvecover or crankcase helps seal the rings and helps keep oil from being blown around so much,helps keep gaskets from blowing out.dragbikes are generally run a little low on oil to save on crank windage as it trys to turn its way through oil;)

I got a couple of questions pertaining to this topic if I may:

1.) Can the 4 emission air injection holes in the KZ head be plugged and staked?

2.) If number one can be done can you then use a Z valve cover, using standard lift cams, instead of the fugly KZ reed valved cover??

Thanks in advance..

deleted by author. double post. note to self, "do not use back button"..

Post edited by: MaD MiKe, at: 2008/03/02 04:54

Yes you can (head OFF engine) drill, tap and plug the holes. And then you can use any pre smog cover. I have a chrome one I was gonna put on mine but then realized the holes were there..... oh well.

Yes to both questions.

I filled the holes in using epoxy (QuickSteel I think), haven't had a problem with it.
Sure beats taking off the head just to plug those holes.

Great minds think alike but I couldn't think of the proper epoxy to handle the heat.. Thought of roughing up the holes with 80 grit, piece of duct tape over the hole in the exhaust port then fill the holes from the top with high temp epoxy. Just didn't have a name or brand of epoxy yet.. Thanks for the suggestion..

By the way the head is off, for a fresh valve job, so drilling and tapping in the exhaust port wouldn't be a problem..

Bluemeanie wrote:

Yes you can (head OFF engine) drill, tap and plug the holes. And then you can use any pre smog cover. I have a chrome one I was gonna put on mine but then realized the holes were there..... oh well.

Pull your exhaust off, make sure the exhaust valve is closed on the cylinder you are working on, drill and tap away.. Once finished vacuum out the exhaust port and move on.. If any small shavings per chance get into the cylinder they will vaporize with combustion..