22 replies to this topic

[Jana]

I first posted this in another thread (http://www.carpe-tdm...=343&hl=diamond), but I try a new thread with better title so more people see it:

Trying to develop this method further:
Here it is, resonably level, really don't think it matters bacause float didn't seem to move if i tilted it a bit.





The tools



The thing on the left is 16mm above the meassuring point. So is the foam thing on the right. Ruler sits on both of them.
Using feeler gauge to meassure gap = 2mm



Another pic of the gap:



So 16mm - 2mm = 14mm

Float hight is 14mm?

Do you think this is a good way to do it?
Is 14mm ok for a MKII?

Apreciate some advice!

Edited by Jana, 19 March 2011 - 08:08 am.

[dapleb]

Do you think this is a good way to do it?

Why not just get a ruler and put the end flat on the gasket surface (using the correct float of course) or even a set square?

Sorry, don't know what mkII float height should be.

EDIT: If you look on the Factory Pro website, they have destructions, though not mkII specs.

[Studley Ramrod]

It does look kinda complicated compared with the fuel level method of setting the floats.

[TDMTAM]

I used a router depth gauge to help check the float height on my old mkI
TAM

Edited by TDMTAM, 19 March 2011 - 10:05 am.

[Studley Ramrod]

Pure genius Tam

[Jana]

Do you think the method is ok and the result is to be trusted if done this way?

[Studley Ramrod]

I've never tried this method so can't say if you will get a good result. Also, if you don't know what the float height should be then you won't really be able to set them up properly.

If your carb float bowls have the Mikuni word stamped on them, which I think they should, it would probably be easier, and more accurate, to measure the fuel levels. All you need to do this is a small length of transparent pipe and a ruler.

Also, I notice that Yamaha and Haynes don't use the float height method and both use the fuel level method.

Edited by Studley Ramrod, 19 March 2011 - 09:23 pm.

[Jana]

Tried the other side also, Same method.Right Carb:16mm - 2mm = 14mmLeft Carb:16mm - 4mm = 12mmMost people seem to prefer 13mm so I guess I will try that.How do I adjust these things? Bend the plastic?

I've never tried this method so can't say if you will get a good result. Also, if you don't know what the float height should be then you won't really be able to set them up properly.If your carb float bowls have the Mikuni word stamped on them, which I think they should, it would probably be easier, and more accurate, to measure the fuel levels. All you need to do this is a small length of transparent pipe and a ruler.Also, I notice that Yamaha and Haynes don't use the float height method and both use the fuel level method.

I might try the fuel height method, but I will have to remove carbs from the bike to adjust it?Seems a lot of work. Easier to just finish the job while working on the carbs, I think.Also it is pretty cold in my garage this time of year so I would prefer working in the house so setting up carbs with gas is not an option. I could try with water, but that might not be the best idea..

[Studley Ramrod]

You bend the metal tang on the float

IIRC when you measure the float height, the position of the float should be such that it is just compressing the top of the float valve.

Have a look here http://www.factorypr..._procedure.html

[Jana]

Ok, here is an update for my 1997 MKII with Leo Vince slipon:

Ended up just usng a ruler to set the height to 13mm which I thought was a good setting.

After installing the carbs on the bike i meassured fuel level with the method in the service manual.
The correct level i 15,8-16,8mm below the Mikuni mark. I meassured the excact same level on each carb: 9mm below mark

So fuel level is 6-7mm to high!

Bike now starts easy without choke


Funny thing is the bike has never run better. Pulls ok from 2000 and strongly from 3000. No more flat spot or hesitation

I was at least expecting terrible fuel consumption, but when filling the tank today after running 143km it took 7,62 litres.
If my math is correct that is 5.3 liters / 100km or 53,3 Imperial MPG - and I don't ride slow at all. Longest trip on this tank was maybe 20km so it should be possible to improve this quite a lot.

I actually find this a little hard to belive myself so I will keep tracking the comsumption.

I am also in the process of buying an air/fuel ratio meter so then I will now more.
Probably an Innovate LM-1 or a 14point7 SLC Pure Plus 2.

I suspect fueling below 4000 is good and above needs some improvement.

[Studley Ramrod]

I would have thought the fuel would be overflowing if the fuel level is 7mm too high. Were you measuring from the bottom of the MIKUNI word, or from the bottom of the corp. word ?

[Jana]

I would have thought the fuel would be overflowing if the fuel level is 7mm too high. Were you measuring from the bottom of the MIKUNI word, or from the bottom of the corp. word ?

I am 95% sure its from the Mikuni mark. I had the Haynes with me. I made a mark on the carburators with a felt-tip pen so I will double check it again.

[idlebloke]

It does look kinda complicated compared with the fuel level method of setting the floats.

Fuel level method?? Is this something different on MKII to MKI? I've read enough on here now to think that I had seen all the advice. Confusing me a bit with that one Ian....

[Studley Ramrod]

No, the methods are the same for a mk1 and a mk2 Peter

There are two methods for setting the floats, the measure the fuel level method and the measure the float height method.

Fuel level method is



float height method is



Hope this helps !

[Jana]

I am 95% sure its from the Mikuni mark. I had the Haynes with me. I made a mark on the carburators with a felt-tip pen so I will double check it again.

I just had a look under the tank. I have used the correct method.

I also had a quick spin of 149km burning 7,72 liters of gas. This equals 5.18 litres per 100 km or about 54.5 Imp MPG.

I have also syncronized the carbs, adjusted throttle slack, adjusted chain slack, set the correct spring preload.
Feels like a new bike

[idlebloke]

Cheers Ian.

I don't recall seeing that measure the fuel method before. Bit of a pain to keep taking float chambers off, bending the clip, back on, fill with fuel, check the fuel height etc

[Studley Ramrod]

I just had a look under the tank. I have used the correct method.

I also had a quick spin of 149km burning 7,72 liters of gas. This equals 5.18 litres per 100 km or about 54.5 Imp MPG.

I have also syncronized the carbs, adjusted throttle slack, adjusted chain slack, set the correct spring preload.
Feels like a new bike

Cheers Ian.

I don't recall seeing that measure the fuel method before. Bit of a pain to keep taking float chambers off, bending the clip, back on, fill with fuel, check the fuel height etc

It's in the Haynes book of delusional meanderings Peter

[idlebloke]

"It's in the Haynes book of delusional meanderings Peter "

Yh...looked last night and was only method I saw in there. Obviously I must have picked up the 'other' method from here and just forgotten. Serious brain leak!!

[idlebloke]

Ian

I asked you about float heights 4 years ago!!

Sitting here doing some searching to be as knowledgeable as I can when I get back to bike (weather too nice atm and no breakfast yet!)

Is the measurement the same (15.8-16.8) regardless of float height of fuel level methods?

Both heights measured per you pics above?

TBH, I'll prolly do both methods as a double check.  Float height first so that any adjustment will require less work, then (hopefully) confirm all good with fuel level method

 

Edited by idlebloke, 09 August 2015 - 01:35 pm.

[Studley Ramrod]

I dare say the measurement would be the same, BUT, the carbs all have different markings on the float bowls so the measurements will also be different for each model.

 

Assuming the fuel level of the carb where the cylinder is firing is about right, why not measure both carb fuel levels and set the 'other' carb the same as the known good carb ?