83 GPZ305 won't rev past 7000RPM??????

make sure the exhaust has no obstructions.

leon

I replaced the air filters with the green UNI cut to fit. I let it warm up a bit and took it down the street. I got it to 8200 RPM before it fell on its face again. Got another 1200 RPM out of it. What the heck?

If not already done, would assure that the seat orifice in the float valve is clear and thereby allowing ample gasoline flow into the carb bowl (i.e., no fuel starvation due to an obstructed orifice in the float needle seat).)

If the seat is removable -- designed to be unscrewed -- it might have a screen filter on it that could be clogged and thereby unduly restricting gasoline flow through the seat.

Good Fortune!

I took carbs back apart and cleaned them. Blew out all orifices and everything seems clear. Went back down the road and it only got to 7200 before falling down. I can hold it wide open when it does it and keep going but it falls down picks back up and falls down, over and over. Basically its like a surge. I came back and swapped out the CDI box and the rectifier from the parts bike. NO CHANGE. Here is how the plugs are burning. I let it surge all the way till I got close to my driveway then shut it off.

I did a compression test. Engine hot, throttle wide open got 145 and 151

Here is the page from Cycle world on the carb fix. I did it exactly like they said. It does start easier and no more off idle hesitation.

I just had a local bike mechanic come by and test ride it. He said the brass is dirty in the carb. These carbs have been apart and cleaned several times. I just took them back apart and the brass is clean and clear. All orifices are clear. If I blow air into one hole, it comes out another the same on both carbs. These carbs are clean in my opinion.

One other thing to check, although it's a long shot - make sure the fuel line from the tank to the carbs does not have any kinks in it where it bends. Don't ask how I know about this. Ed

ITS FIXED!!!!! When I had it apart, I noticed the main jets and tubes looked different from the parts bike carbs. The ones I had were thicker because of a brass spacer under them. I cleaned the parts bike main jets and tubes and installed them. It hit 11,000 pretty quick on my first pass. So now I don't know if it was another cleaning and blowing out with air, or replacing the main jets and tubes. I had drilled the main jets out one size bigger so it could have been that too. Now I can finally tear it down for new paint and powder coat. I did a happy dance but my neighbor was looking at me funny :woohoo:

glad you got it worked out.

leon

No eBay APP ID and/or Cert ID defined in Kunena configurationfyi - Just ordered for my 83 GPZ 305