still no joy

[youngy]

still sounds like emulsion tubes.

that washer thing - i think the Haynes is wrong. I believe the washer is between the e-clip and the plastic spacer. not that it matters from a setup point of view, just that you won't see it as Haynes suggests.

silly question - did Factory send the correct emulsion tubes? do they look like the oe ones?

could it be when you put the Factory tubes in you did something else not quite right? so it seems to run worse with the new tubes but they're not the problem? try the new emulsion tubes again and make sure the carbs get primed fully befire you start up.

3500 on choke is about right. sounds like you have it airtight at least.

[trix]

Great. Thanks youngy. Yes, the tubes looked to be identical and they fitted perfectly.

I suppose I can try it again with the factory pro tubes and see how it goes. I have adjusted the float height since I last tried them.

By the way, does anyone know how the float height gets out of whack in the first place...is it caused by the seal getting worn on the valve??

Is the flaot height supposed to be 14 mm or 15mm.. Some people have said they set it according the the Factory Pro website but i cant find the actual figure on that website.

[youngy]

afaik there is no Yamaha figure for float height - the manual quotes fuel level.

I think it was Steve Speed found a figure of 14mm on the FP website - possibly in th eTDM section? Mine are set at that now and it seems to run fine.

[steve speed]

yes iam the guilty one ,,just go to the factory pro site look for Yamaha then tdm/trx 850 (they both have the same carbs ) go to the bottom of the page and there it is 14mm float height ,, and i must say mine were miles out , one was 11mm and the other was 12mm ,which made it run rich ,, that's not to bad when the carbs are new but as soon as those tubes start to wear its miles too rich ........ hope this helps

[trix]

I have set mine to 14mm. Mine were also way out, like maybe 8 or 9mm. I had to put a significant bend on the little arm to get them sitting at 14mm. that's why I was wondering how they get so far out of position in the first place.
Yes; the manuals quote a fuel height. I tried measuring this with a piece of clear vinyl tube connected to a small bore syringe tube with graduations on it. the readings made no sense. I might try it again now that i've set the float heights "internally".
I've put the FP tubes back in and built it back up again (i could take those carbs off, rebuild them and instal them blindfold now. I can do the whole thing in about 40 minutes). Couldn't run it as it was too late and the bike is too loud. I'll try it in the morning.

[trix]

I ran it with the FP emulsion tubes this morning. Same problem as before. It just wont run below about 2000-3000rpm. When I take the choke off it just dies. SO it runs crap with the original tubes and doesn't run at all with the FP tubes. I have checked and the FP tubes are the correct size.

There seems to be a problem here. Photograph 8.5 in the Haynes manual clearly shows a large washer under the needle, below the plastic spacer on the needle. It is missing from both my carbs. Does anyone know what size/thickness this washer is??

Also, on my needles, the "E" clip is on the top groove (groove furthest from pointy end of needle). Perhaps it should be on a lower groove? Does anyone know?

[youngy]

The clip should be in the middle position of 3.

If that washer is missing (and Haynes is wrong btw - it sits between the clip and spacer) then your needle is way too low, which won't help at all. As the FP tube is the correct size you don't have enough fuel flowing with a needle 1 1/2 positions too low!

That washer is "thin". It is half a clip position. Try with the clip in either the middle or bottom position.

Can you get some from local Yam dealer? Or a 1mm thick washer with a hole just larger than the needle will probably work.

Sounds like the previous owner had a DJ kit fitted and didn't put it back together properly.

[steve speed]

Trix,, when you say " miles out " and you had to bend them 8,9mm ,, are you sure you are doing this correct ? the float should be just closing the float valve but NOT compressing its spring

[trix]

Ok youngy, sounds like i may be getting somewhere!!. My needle clip is in the wrong position. Unfortunately haynes says to note which position its in before you take it apart but doesn't tell you what posn it's uspposed to be in, in the first place. What does yamaha say off the top of your head?

There is a thin washer between the "E" clip and the spacer both on my bike and in the haynes. But in the haynes, there is definitely another, much larger washer underneath the plastic spacer. Have you looked at Picture 8.5 in the haynes? Perhaps this is for the TDM?? Youngy: you sound sure that there should not be another washer under the spacer?

I'll move the clip down one position and see what happens. But looking at that picture in the Haynes book, it seems like I would need to move it down 2 grooves to account for the "missing" washer!

Steve speed; I meant when I measured the existing float height it was about 8 or 9mm so I had to increase it by about 5mm to get to the 14mm figure. Yes, I was measuring it from where the floats just "flopped" down onto the needle, but were not compressing the spring, and I was measuring the height of the larger float...apparently the top of the smaller, trapezoidal float sits about 3mm lower. I checked them again last night when I had them off.

Seems I'll be taking them apart again tonight. Its like my regular evening routine now. Bikes been off the road now for weeks it seems. Still I took the opportunity to change the fork seals, put on braided lines and regrease the head bearings.

[youngy]

Trix the clip goes in the middle position out of 3. For sure.

There is no second washer. None. Zero. Zilch. Nada. The one and only washer goes between the clip and spacer - there is only one. If you look at the Yamaha service manual and the Yamaha parts book you will see this.

Take the Haynes with a pinch of salt - it's great as a general guide but does not neccessarily reflect the model name on the cover - it is a generic book of lies.

[HansJ]

Complex problems calls for drastic solutions/thinking, so I am throwing in something else Have You cehcked the diaphragm in the carbs, no leak there? It sounds like previous owner cured worn emulsion tubes by moving the clips, so with new emulsion tubes You're suffering from too weak mixture. Have You checked that the main jets, air screw etc are correct, in case someone has tried other solutions for the worn tubes?

[trix]

OK youngy...I believe you!
Yes HansJ, I think thats exactly what's happened. They've dropped the neeedle down so a fatter part of the needle sits in the tube at low throttle, taking up the worn out clearance, so now its starving of fuel at low throttle. See, I thought that was maybe why the washer was removed, but youngy has convinced me it was never there to begin with.

I should check all the other jets too. I had them all out but I never noted the numbers.

The diaphragm seems ok visually. I gave them a good clean and there is no perishing/cracking of the rubber...but will check again. There's a nice puff of air when you push them up and down when the carb is assembled.

[youngy]

trix - there are only 3 grooves on your needles, right?

[trix]

Yes there are 3 grooves; standard mikuni needle.
I put it down to the middle groove and its vastly improved. It doesn't stall below 2000 rpm anymore. take off is a bit poor, theres a big hole at about 3500 to 4000 rpm and it smokes quite badly when revved......but definitely an improvement. I've taken the carbs off again and moved it to the lowest groove to see what happens. Again, its too late to run it now, so I'll try it tomorrow evening.

While I had the carbs out this time i've checked all the jets etc...they're all standard mikuni parts and the numbers on them are as quoted in haynes. the pilot screws are 2.5 turns out from full in.

[youngy]

pilot screws should be 2 turns out, not 2.5.

2.5 is the DJ setting - more clues!

With 2.5 on my stock carbs, it pops and bangs horribly. You may well find it improves alot with 2 turns out.