Homemade Carbtune vs store bought?

Anyone here seen a comparison / test of a homemade versus a bought one? Someone here doesn't believe that they are accurate and I'd like to show that they are.

So then do it.
Steve

Quite hard unless you come by with something to test it against.

Take a vid of yours and I'll take a vid of mine.
Steve

But... you have to test them on the same bike to see the difference.

I'm going to do a sync on mine soon, I'll take a video.
Steve

Do you have both a home made and a Carbtune?

So you want to know if a monometer would compare to 4 independent vacuum gauges (like a Morgan carbtune)?

They should do exactly the same thing. one is a relative measurement, the other absolute.

Close, I want to show it to someone who doubts it works like that.

There are a bunch of YouTube videos of guys using home made rigs. They seem to fall into two basic designs. Some are made with vacuum guages , though those can be bought commercially. The others tend to be made of jars, a bunch of vacuum hose and some oil. Two-stroke and ATF are popular as they are cheap and easy to see. I heard about one made with plastic tubing and ball bearings, much like the factory issued ones from Suzuki back in the day. I have been told by folks who know much more than I that the exact measurement is largely irrelevant as long as they are all the same.

I agree. A ball valve can be set differently than the others thus give a false reading. A metering jet/s or check valve/s would help in this case.
Steve

I'm using this one: