Plugging air suction system?

Any harm to the engine by plugging the air suction system on a 750 four? In this case a KZ750H3. I have often pulled air pumps from older cars (which do basically the same thing) without ill effects to the engine. Wouldn't this have similar results?

no ill effects

Sure, remove the valve and all hoses and vacuum lines. Plug nipples at carbs and just run a 3/4" hose from valve to valve on the front cover. You may actually have less popping on de-acceleration. Did mine over 20 years ago with no ill effects. I don't know of anyone who still has a functioning system. If you don't remove it voluntarily the valve usually dies from old age anyways.

The only ill effect that I have ever experienced is that your exhaust valves will run hotter. This also means that either the chrome will blue more or you will burn the paint off faster on your headers. Performance wise, there is no effect either way. I decided to install it on my scratch built GPz1150 just for keeping the exhaust cooler.

Even though the system was implemented strictly for complying with the emission laws of the US, it makes sense that fresh air would also cool the exhaust valves somewhat, as a welcomed byproduct. Never thought of that.

Just wondered whether if you do remove the emission system. Should you plug the hole in the airbox where the rubber hose enters?

Well, I was thinking, since the intention of the system is to continue burning any unburnt gasses as they leave the chamber, wouldn't removing the system allow the exhaust valve area to run cooler? As you no longer have gasses burning at the start of the headers, that area should be cooler...no? One of the reasons auto engines went to hardened exhaust seats and valves (aside from the removal of lead in gas) was because with the air pumps that area ran hotter. Or am I thinking backwards?

That was just BS that was fed to the EPA about burning unburnt gases. It actually only dilutes the exhaust gases with clean air. The system works on vacuum, which means that by the time the air gets there the exhaust is prety much past.

Tommotbird,
I plugged the hole in my airbox with a plastic furniture leg plug from the local Ace Hardware. Perfect fit, perfect depth, perfect color! This was a KZ1000, but the hole should be the same size, I believe.

Thanks Switch
Good tip
Tommotbird

Tommotbird wrote:

Just wondered whether if you do remove the emission system. Should you plug the hole in the airbox where the rubber hose enters?

I had a couple of these plastic plugs laying around when I removed my emmisions. They have a foam insert so they are actually tiny little air filters and with some minor trimming it popped right in and has been there for over 20 years and looks factiory. Sorry I can't help you with where to get them.

I got it all off okay, and I found a plug for the air box, and caps for the carbs, but I can't find anything to cap the tubes on top the cylinder head. I've got caps that are too small to stretch over, or some that are just too big and will leak. I'm guessing the tube size is metric, but can't find any big metric plugs. I could probably make something from the original hose, but I want it to look nice. What have you guys used?
Thanks!