Starting my '89 ZXR750 for the first time in 7 years, carb Q

[metaltriumph]

Just clean the bloody carbs - otherwise you will be having annoying issues like this all the time.

[rexxxy]

Sounds to me like your pilot jets are still blocked.

The line from the tank just sounds from the description like it's the overflow or something, but I could be wrong.

Finally got a chance to spend some quality time with the ZXR today. I pulled the carbies off and found all 4 pilot jets blocked. Cleaned them out, reassembled and it now idles without choke! It also seems to be revving properly, but I now have a fuel leak, that will be easily fixed.

Thanks for the tip MickLC!

[netbikes]

while the carbs were off did you remove and clean the emulsion tubes? if you did not I highly recommend you do so. They are a problem area on bikes that have been sitting for some time, stale old fuel will quickly block the small holes and most people do not think to clean them or even know they are there.

Here is a pic of tubes from a XS400, they need to be very very clean otherwise you will get erratic running. I drop mine in pool acid.

[rexxxy]

I have to pull the carbs again for the fuel leak, so I will pull the tubes and give them a bath, I also stripped the head on one of the fuel bowl screws today, and I will replace all the phillips head screws with hex.

As a side note, I was about to dremel a slot into the head of the screw so that I could get a flat head screw driver onto it, I had just fitted my last dremel cutting disk I had onto the dremel, I knocked the dremel as I was reaching for an extension cord, and snapped the disk, I was ready to call it a day, but I tried one last trick, I put a rubber band between the screw driver and the stripped screw head and like magic the screw driver gripped and I got the screw out.

[rexxxy]

Well some good news, I rushed home this afternoon, tore the tank, airbox and carbs off the ZXR, grabbed one of the fuel bowl screws and made it to the bolt shop just as they were closing and picked up 16 hex headed screws to replace the factory phillips screws.

Back at home, I carefully (for about the fourth time) one by one pulled the fuel bowls off, I removed the emulsion tubes which were covered in crap, gave them a bath in carby cleaner and a clean up with a bit of wire, then I checked the float movement and gave the mechanism a squit of carby cleaner. One of the floats was sticking pretty badly, but free'd up with some movement and a good spray. I checked all the bowl seals which seemed to be in good condition and reassembled using the new screws. I put the airbox back on, the tank on an fired it up, it was running rough, so I checked each clyinder by burning my hand on the headers, found number 2 cylinder was not firing, it was getting dark, I pulled the tank off, and the plug out, it seemed to be OK, it wasnt wet, I gave it a quick wipe and put it back in, with the tank off, I fired it up again and felt the header, it was hot! So I slapped the tank back on and fired it up, finally it sounded like I remembered, I only used the choke for maybe 5 seconds, but it idled fine on its own, a little slow if anything, but easily fixed, once warmed up, I have it a few good revs just up to about 6K, I forgot just how good these bikes sound.

So, engine is running well now and making all the right noises, now for the roadworthy items!

Big thanks to everyone who has given me some tips, I would have probably pulled the carbs off and paid to get them rebuilt if it werent for your help. Carbs will be recoed eventually, but knowing the bike runs well gives me good reason to keep at it.