Yes it took a bit of finding in the end, the bowl covers had a machined boss " Breather hole " near the top and kept leaking petrol changed the covers and still the same also checked the float height and float needle valve and they were ok, after much messing about got it to a slight leak when full the pump occasionally ticked pumping more fuel into the carbs so once again got the carbs stripped on the bench and pressurised the fuel line ( blowing down the fuel pipe ) which lifts the float but when I held down all the floats air was leaking, found it to be passed the float needle brass seat O ring, popped all 4 out and fitted new O rings and job done
Now need to double-check the float height and looks to be sorted
Never had this before must have perished when stored
Last Edit: Apr 28, 2020 18:34:27 GMT by cromwelluk
Thanks for teh update. If ever I get an overflow on Mikuni CVs now I check those pesky o-rings. Had the same problem with my XJ and then on the FZ. I think they must be an imperial size as I can a get an almost fit size in metric that work but you can tell they are not 100% correct.
Think I set my floats to 10mm. To balance all my carbs I use a clear plastic tube wound with a few loops in it. Ball bearing in the loops. One static as a reference, the other has to sit level with static one. Each end of the hose is connected to a carb. Works like a charm and cost me less than a tenner around 5-6 years ago!
vtr: Hi from cape town; new at forum's not at bike building; the insanity is contagious. Recently acquired a "1FU" FZ750 with dropped valves and decided cool to rebuild as a 911conversion sleeper, what we do to ourselves...
Oct 28, 2018 18:19:43 GMT
Bill Inger: Hi Horse, I know this is a number of years ago when you was looking at a cable conversation, did you get it sorted. and could you help me with my race bike that I uses in the superstock at the CRMC. Cheers Bill
Jan 13, 2019 9:42:57 GMT
grahamfirestorm: Hi everyone my name is graham,from wakefield w.yorks,just acquired a restored 1991 fz750.
Jun 23, 2019 19:52:52 GMT
grahamfirestorm: Can anyone tell me why my bike doesn't seem to light up after 7000rpm like all the research I did before buying it.She has the standard 4 into 1 exhaust,carbs rebuilt with new jets,seals,floats,2 new diaphragms,all valve clearances checked and adjusted?
Jun 23, 2019 20:00:50 GMT
grahamfirestorm: She revs round to 10000rpm ok,but there is no urgency with it,my 1987 Kawasaki gpx750 was a lot quicker,and that was supposed to be 10-15 bhp down,ive been told the standard silencer and air filter are to blame but I don't believe that.
Jun 23, 2019 20:10:33 GMT
grpollard: After a header pipe ring nut (for starters). After 15 plus years trying to get my fz back on the road
Oct 6, 2019 9:52:13 GMT
2manyprojects: Hi all, just aqquired 2 FZ's (only one for me, one for nephew). Have a stable full of bikes, I do have a problem, some say its madness! Am based in North Devon, yes where its always raining! Lol😂
Oct 14, 2019 17:14:31 GMT
Graham : grahamfirestorm. Do you have standard size main jets fitted to your carbs? I would be tempted to go up a size or even two to see if it helps the bike pull stronger at high revs.
Oct 15, 2019 18:57:05 GMT