won't rev up even full throttle

Thanks for the confirmation. I know I've been able to run my tank dry without one, and haven't noticed any difference in behaviour related to fuel level in the tank.
I guess if I can locate one, I'll buy it.

 

my bike is a 3ln-1 and doesnt have a fuel pump.....no dramas with out a fuel pump

 

Hey I'm new to the forums, i joined seeing as i too have the same problem, trying to look for a solution. I recently bought a 90' Yamaha Fzr 250 (dont know what 3ln is etc.)

When i first got the bike, it would start fine except for it to act real sluggish in the low rev range between 3000-6000. I soon realised that if i didnt take off at a higher rev (around 5000-6000) my bike will just cut out as it will flood itself. I have spent 2 weekends so far on it and have got two results.

Firstly, we adjusted the pilot jet needles to the 2nd level to lean out the fuel going into the carbies. We also adjusted the idle screw mixtures (we screwed them all the way in) then we screwed three full turns out. This resulted in the bike turning on fine, taking off fine, no problems with the bike actually running, no rev/throttle problems. I was quite happy with it BUT what i noticed was that since the fuel going into the carbies in the low range was fine, for some reason there wasnt enough fuel going through when i was in the higher rev range THUS dramatically reducing the power of the bike.

I am currently still working on finding a balance to solve the issue as I have yet to find a solution through looking through the forums.

 

The needles that you adjusted the clips on to get to the second level set the main fuel ratio at high throttle openings. The idle screws work at the low end of throttle openings. Set those accordingly. Check that the float bowl valves are sealing properly as these will make the carb bowls overfill at low throttle demand, hence running rich.

 

I have been REALLY slack, plan was to find some time and get the bike running well enough to learn to ride. Problem is 6 cars, 7 regos, 3 kids, lots of hobbies and concerns about work / money.

Still keeping an eye out for an affordable fuel pump and kits to rebuild the carbies. No updates to report.