My unending quest to get it right

I know I have been jumping around from this to that but here is the bike as it stands. I put a kerker 4 into 1 exhaust on it from a parts bike that I bought. I put the 115 mains in it and the bike doesnt like the throttle to much. I can ease it into higher rpms and it does fine. The plugs do not look sooty, just a little bit of black and mostly brown. Before this I had some kind of funky header and an open cone muffler with no baffle. The bike ran fine other than the hesitation after about 4500 rpms with the unknown headers. Before I changed the main jets there was 112.5's in them. These are carbs from about a 78 KZ 1000. I have a set off of my parts bike that are factory for a 75 Z1 900 and would like to use them but they need the T fittings for between them for the supply lines. Do I need to get bigger mains? Do I need to put it back to the 112.5's? I am getting a little used to pulling the carbs at this point but I would like to have a definate ( yeah I know) before I pull them again. The closest bike mechanic to me that works on the older stuff is about an hour away. Dealership wont touch anything more than ten years old. I have tried to work on it but I just cant seem to get it right. (the valve clearances are fine, as well as the timing and the coil voltage.) By the way I will be selling the parts bike in pieces soon.

Ok, I bought a set of #125 mains from a nice fella in Bessemer City that works on these bikes. By the way man if you are by any chance on this forum thanks a million! I put some O-rings on the t fittings and that solved the leaking problem there. I put in the rebuild kit, as well as the new #125 mains, with 17.5 pilots. Now I still have a leaking problem from the overflow tubes, and the float levels are correct. I also developed a bad oil leak from around the sprocket area and from the case cover on the left. I guess I will be buying gaskets and seals next. One other thing, the bike backfires some when I let off the throttle now. What could that be from? Other than that the things will cruise at ease at any rpm's with no hesitation! Almost there. The thing being near 35 years old I should have expected some oil leaks.

jdsmithinc wrote:

One other thing, the bike backfires some when I let off the throttle now. What could that be from?

On my 750, that only occurs when the pilot circuit is too lean (YMMV). You can rich it up some with the mixture screws, or by going up in pilot jet size.

jdsmithinc wrote:

...still have a leaking problem from the overflow tubes, and the float levels are correct....

Am hoping fuel levels inside float bowls were verified correct by using the clear plastic tube test method before the overflow issue arose.

The clear plastic tube test isn't accurate under overflow conditions.

If not already done, would first correct whatever's causing the overflow, and thereafter perform the clear plastic tube test to assure service fuel levels are within specs.

Good Luck!

jdsmithinc wrote:

Now I still have a leaking problem from the overflow tubes, and the float levels are correct.

Then it must be that the float valves are not sealing well, if the fuel levels were actually correct. Take the float needles out and see if the tips are funky or rough.

Bad news, I went out this morning to start the bike and ride it to work. I started it with the choke, and let it run a minute before taking the choke off. I started out of the driveway and it wasnt running right, I believe I have fouled a plug or two. I guess the #125 jets are too big. I really dont know at this point until I get out there to look at it. As far as the pilot screws being too lean and adjusting with the mixture screw which way should I turn the screw richen it up? I dont want to go any richer if the plugs are fouled due to the main jets.

Man it never stops. I was trying to figure out why my overflow tube was leaking and figured out that the overflow tube that is inside the bowl on second from left carb has a hole in it. Any ideas on how I can fix it other than putting another bowl on it? Also I believe I will have to go down to #120 mains because the bike is getting too much fuel (smoking a little when revving up)

There are a couple of earlier threads dealing with repair to a crack in an overflow tube.

Good Luck!