Vacuum Gauges

Okay, so I have decided to bite the bullet and buy a set of vacuum gauges to help tune up the bike. I think in the long run this will pay off for me in a number of ways, including yearly tune ups and faster tune ups. My question is this - What should the vacuum gauges read on my bike when I fine tune it? Its the XJ550 (if that helps).

 

On my 550, thus far, the gauges flutter wildly between 0 and about 10 in. Hg. I will be dampening the gauges before trying to continue.

 

My gauges were fluttering lower than 10in-Hg, so I flipped them upside down as per the Morgan Carbtune instructions. Now they read in the middle of the gauge. It isn't really the amount of vacuum that is important in the syncing process, but the levels with respect to each other.

 

Cheaper and easier to go to HomeDepot and get 20 feet of clear tubing for $7 and $1or$2 of 2 stroke oil, and a $3 yard stick.

Attach the tube to the yard stick leaving about 6 feet hanging over in equal lengths to go to carbs. Fill the tube with 2 stroke oil until both sides are even about 1/2 up the yard stick.

Jam a oil soaked rag or rope into the YICS chamber and bolt it back up.

Synch 1 and 2 and then 3 and 4 (or 3-4 and 1-2) then synch 2 to 3. Adjust the idle and bada bing! Cheap and easy.

Don't forget to remove the YICS blocking fabric.

With the oil, the tubes won't flutter.

 

I add a small length of "the tube you get on a can of WD40" at 3 inches from the inlet manafold end to act as a damper as well. Using the above home made tool is far better than the guages and alot cheaper too!

Mine

 

So where do I connect the tubes when I sync the carbs? Is it those covered up "holes" on my manifold intakes after the carbs?

 

Yes. the vacuum fittings are on the tops of the intake boots.

 

Spending the money for a Morgan Carbtune will pay off in the end though - always ready, always accurate, easy to store, no liquids to worry about, etc, etc, etc.

Sometimes spending a few bucks for an excellent tool is worth it....