a little lost

I just got my kz750 out of the shop. The carb was rebuilt
now it starts and idles well. but I had the stock air box
removed and pod filters put on and now it has no power at all.

This is where I'm lost. I don't know how to ajust the carb to get it back to where it was. I'm thinking it has something to do with the air mixter screws on top of the carbs.

I don't want to screw anything up. Any pointers would be cool.

It probably needs larger jets. Is the power loss throughout the powerband or in the low or high revs?

get your self a dyno-jet kit they still have them available for your bikewhen you remove the air box and install pod's it completely changes the amount air of that is available to your motor. try going bak to abase line setting with your carbs fuel screws stock thety will be 1 1/2 to 1 3/4 turns out from bottom i'd try 2 1/2 turns out to see if it is better remember to give an engine what it want's.

Quote
"I just got my kz750 out of the shop. The carb was rebuilt"


What year ? and is it the 2 cylinder or a 4 cylinder model ?. and if 4 cylinder and 4 carbs then are the carbs Keihin or Mikuni's ?
What about the exhaust system ? Original or modified ?

83 I think, inline 4,Keihin carbs, original pipes .

the power loss is through the whole band.I don't know where the fuel screws are.

zim6000 wrote:

83 I think, inline 4,Keihin carbs, original pipes .

the power loss is through the whole band.I don't know where the fuel screws are.

I hate to say it and I know some will disagree with me but...put the air box back on. It will run perfectly and you can enjoy your bike. Even if you get the jetting right with the pods you won't get much of an increase in performance if you retain the stock exhaust.

Carburettor tuning is an acquired skill. If you want to learn about carburetors, buy a jet kit and plan to spend several days taking your carbs on and off and fiddling with fine adjustments in the hope of getting the bike to run the way it did before you removed the air box.

my 2 cents

thats what I wanted to try but 2 of the 4 rubber connectors
that go from the box to the carb shrunk and won't fit back on. so now it looks like my options are buy a jet kit or order new rubber thingys :S

zim6000 wrote:

thats what I wanted to try but 2 of the 4 rubber connectors
that go from the box to the carb shrunk and won't fit back on.

Are you sure they shrunk? How did they shrink? Usually they will get a little dry and hard with age. This will make them a difficult to fit over the carburettor mouth. If this is the case, spray them with a little WD40. It will help alot. If they're too far gone, call Jeff at Z1.

Just so you know. I have an 82 GS1100E that is bone stock and runs like a bat out of hell at all RPMs. (it will give my heavily modified KZ1075 a run for its money) I've tried to run the GS before with the airbox removed and I can't even rev up the engine in neutral.

From Z1E

del

If the inlet ducts/rubber tubes have shrunk try some just below boiling hot water. This will soften up the ducting and allow re-installation. Another trick is to use rubbing alcohol as a lubricant fitting the ducts to the carbs or airbox fittings.

Laugh, but I used hair spray on a set way back when. Just like when ya change grips. Just don,'t take too long or ya hav ta spray em again.