i have a 92 zx750-j that i just bought. it starts up but then quits after a little while. ignition board is fine. it will only stay on if you keep it reved high. heard the fuel pump is suppose to stop pumping once it hits the right pressure but this one just keeps going as long as the key is turned. dont have the money to really be taking it to get it completly checked out by a mechanic. its my first bike. please post anything that you think could help.

 

nice, a zx7 for your first ride. Get a manual on that thing first of all. As per quoted in 15-45 of the '91 zx7 manual....When fuel level in the float chamber islow, the fuel pump operates to supply fuel into the float chamber. When the fuel reaches a certain level, the fuel pressure rises (1.6-2.3psig standard pump pressure) , and the fuel pump stops. It then tells you how to test the fuel pump relay and pump inspections.

Congrats on owning the mighty zx7

 

The 7 is one of my all time favs. Welcome zS. Fresh fuel? How long since it has been run before you got it? Have you drained the bowls and refilled, (using the little drain screws on the bowls) just to ensure a. fresh fuel, and b. proper float level (assuming no sludge or other restrictions.) Does it "sound like a turd" (as in, bad fuel or only 2 or 3 cylinders firing?) Check your plugs. All with good color and dry? Black and wet? Get fresh plugs and fresh fuel. Drain and refill carbs. Report back to us.
Welcome again. We'll get you going.

 

when it does run it runs just fine. dont know when it was running good last. bought it 2 months ago and have been tinkering on it. going to take the carbs apart tomorow and recheck/clean them to make sure. it sounds great for a few seconds then just dies off like its not getting enough fuel. im guessing since the fuel pump doesnt turn off from being pressured that its getting flooded but thats just my guess and ive never worked on bikes before and have hardly any knowledge of cars and engines in general.

 

or not enough fuel....either way....I like Jeffs quote

 

lol thx all. the gas tank is full so i suppose it could be the fuel pump. but we hot wired it and it was pumping. dont remember if it stopped when we put our fingers over it.

 

ok cleaned the carb out. it actually had alot crap in it. also noticed they replaced the fuel pump relay with a couple of 5 amp car fuses. is that alright?

 

Replaced the relay and bypassed it direct?

 

just bypassed it with a couple fuses to protect it. dont know if it actually makes things worse or if it will even work the way they have it. trying to solder some old connectors onto it so i can use the original plug and relay. does anyone know which colors is on which part on the plug? plz post.

 

ok soldered the old conectors on and put on the old fuel pump relay. didnt work but jumped 2 wires on it and it works great. now i just need some cheap plastics for it and change the oil and oil filter and ill be driving it around like crazy XD