Carb Questions

[trix]

I was having difficulties starting and when I would finally get it started it would only run on one cylinder. Youngy and dfh correctly diagnosed that my valve clearances needed checked. A few others suggested emulsion tubes. I reset all the valve clearances to within tolerance and put in new factory pro emulsion tubes. It started easier but would not run below about 2000rpm, without choke and was making no power. I thought maybe my valve timings were out so I restripped, confirmed they were ok and rebuilt again but with the same problem. Then I decided to put the old emulsion tubes back in. Hey presto, now it starts and runs ok again.

Question; with the factory pro emulsion tubes, I think its running too lean at low throttle. The haynes manual advises to watch out for a washer when you're removing the needles from the diaphragm slide. There were no washers in mine when I took them apart. I wonder if someone has removed the washers to try and compensate for the worn out emulsion tubes, such that when I reassemble with the Factory Pro tubes, the needles sit too low and are making it too lean? Can anyone tell me if there are washers underneath the needle as standard. There's a relatively thick plastic spacer near the top of the needle but no washer beneath it.Its not clear from the diagrams in the workshop manual.

Also, I tried to check the float height by the method recommended on factory pro's website but did not know where to measure from or to. So I then tried to check the fuel height by connecting a clear tube to the drain cocks and comparing the height of fuel in the clear tube to the line marked on the side of the float bowel as described by Yamaha (with the carbs on the bike and the bike upright and level). However, the fuel would not rise up the tube for some reason and was nowhere near the mark (should be within 5 to 6mm), even though fuel would piss out of the tube if I pointed it downwards below the level of the carb. As the bike starts and runs ok now, I assume the fuel level cant be too far out, so I cant understand why it doesn't come anywhere near to the mark on the side of the float bowel. Basically I haven't been able to check or set my float height. Anyone got any tips?

[burty]

Yes there should be a thin washer and the spacer you have on the needle. The washer is equivalent to half notch on clip height so that is probably why they are not there. TBH I wouldn't think this would make a big difference at tickover. But I'm not an expert.

I reset my float height using the instructions on the factory pro site, i.e. from within. But it was tricky.

Does the bike have standard main jets? Have you reset the pilot screws?

[youngy]

I thought the stock washer sat above the plastic spacer. Not sure though.

Low fuel height is because your float height is too high. Doesn't mean there's no fuel, which is why it still pours out when the drain is lowered. Means it is lean though.

What setting do you have on your pilot screws? Stock is 2 turns out. DJ recommend 2.5 with their needles.