Christmas Carb balancing assistance

[Griff the spanner thrower]

I am about to try balancing the carbs on my XS650B. Does anyone have any top tips do's dont's im using dials not digital equipment, im looking for smoother running.



Many thanks Merry Christmas from the UK

 

[Dakota_Lew]

Build your self a home made manometer, Travis's 1st post.

http://www.xs650.com/forum/showthread.php?t=37

 

[Griff the spanner thrower]

Build your self a home made manometer, Travis's 1st post.

http://www.xs650.com/forum/showthread.php?t=37

Hey nice one....... My wife bought my dial balancers for christms but will try the manometre

 

[angus67]

if you build the manometer, put some old pilot jets in the hoses. or anything that will fit in the hoses that you can put a very small hole thru. it will slow down the engine pulses making it a little easier to read. If you dont have old pilots, you can use those cheap aquarium air line diverter to constrict the lines.
your not really looking for a set measurement, just a equal balance betwen the two.
GGGary used dials I think. He may have some tips on using those.

 

[retiredgentleman]

There is a step you should do before using a manometer.

If you suspect the balance is way off, you should remove the carbs to the bench. Once on the bench, you can use a strip of paper as a feeler gauge. Slide the feeler gauge under each butterfly, and adjust the centre (sync) screw for equal drag on the feeler gauge. That will get the carbs very closely sychronized.

This step prevents sucking the fluid into one of the cylinders.

I have found no need to use any restriction in the lines. The levels wil pulse somewhat, but just adjust until the levels are approximately equal and you're done.

Be aware that only a very small adjustment will make a big difference in the levels. Its a very sensitive gauge, and that is why its very accurate. Vacuum gauges are meant to measure intake vacuum, not differential pressure. They are not very accurate to balance carbs.

 

[Downer]

When using a manometer should you get the levels close at idle? When reving should the levels change then return to the same level? What if one is higher then the other after reving?

 

[grepper]

When using a manometer should you get the levels close at idle? When reving should the levels change then return to the same level? What if one is higher then the other after reving?

The levels should rise and fall together. They may go down as the vacuum increased as the revs get higher.

 

[retiredgentleman]

When using a manometer should you get the levels close at idle? When reving should the levels change then return to the same level? What if one is higher then the other after reving?

I just adjust with the engine idling. Yes, the levels will not stay exactly even when reving the engine. Yes, the levels may be slightly different after returning to idle, so do a tiny adjustment on the screw. Rev it up and readjust as required, perhaps 3 times, and you're done.

You have to realize, that the manometer is extremely sensitive, and so even a slight variation between carbs will show up as a level difference. As long as the levels are within a couple of inches of each other, that is accurate enough.

 

[Downer]

Thanx guys

 

[Griff the spanner thrower]

Thanks to all who have contributed

Happy New Year from the UK