Topic: Homemade Manometer

[OldSchool_IsCool]

The trouble with that idea is changing one carb affects the others.  You really need to see the pull from all four at the same time.

[tlbranth]

I made this mercury manometer back in the early 70's. There was an article in Cycle World or some such. Each column is actually a U-tube bent using a propane torch. The hose is surgical tubing. I made my adapters by drilling holes longways through the appropriate bolts (actually my dad did it at the sheet metal shop where he worked) and screwing the bolts part-way into some 1/4" copper tubing. I put a nut and o-ring on each bolt to seat it to the carb. The surgical tubing then slips over the copper tube. I just resurrected the thing to tune my bike which hasn't run in many years.

[mark]

That looks like art. You could tune a Rolls with that setup.





Now a question.....

Are the u-tubes connected down inside there somehow?

[tlbranth]

Mark, Yes the tubes are held down with wire through vertical wood supports which are perpendicular to the front panel and twisted to hold tight.

[UnCrash]

And having said all that, let me tell you - I tried both. That is, I borrowed a manometer-set one, and i made myself one with the tubes. The tube one is MUCH MORE sensitive and accurate. No problems with damping, and satisfaction of making it by myself - priceless....   It came to the stage where tightening of the locking nut would affect the setting. It's that sensitive.

In looking at this setup I wonder why you wouldn't terminate all  4 hoses into a single container...  I guess the long hoses all joined together at the bottom works the same...

I'm thinking of rolling one up tomorrow.

Yes, for me $80 for a Morgan is a great sounding deal, but with all the other odds n ends I need it isn't in the budget.

[torrinh]

hey ben,

if you build one with hoses that terminate into a shared reservoir make sure its airtight. I made one that way and could never get it to seal, so it would suck the oil up the tubes into the carbs.

[UnCrash]

I received my Carb manifold adapters from Z1 today and headed out to the shop to finish up my home made manometer / vacuum gauge.

I build it based on a design shown earlier in this thread by Tower using 1/4" tubing, and a couple outdoor plant watering kits from Lowes for all the connectors.  Lowes even has on/off valves for the watering system which I used as restrictors.

It took a while to dial in the restrictors in evenly. I filled the tubing with a gas/2stroke oil mix for my weedwacker.  Finally everything settled down on me and I could synch the carbs.  Now the tool is dialed in and so are my carbs.  Smooth idle at 1100 and will idle down to 900 if I let it.


The ZI adapters were $15 including shipping, and the tubing and assorted other parts were about $10.  Here's what I ended up with.

[ekpent]

Most people use ATF. This is a real old thread. For a $100.00 and if you have a lot of bikes,lots of friends,or plan on riding for a lot of years this is not a bad investment.Good tools last your lifetime

[seanbarney41]

got my homemade manometer finished the other day...check the photos...tubing from Lowes...vacuum t fittings from autozone... 5mm carb fittings from Z1 Enterprises, used 145 main jets for restrictors...(yes you will need restrictors, I thought the fittings from Z1 came with restrictors but no, I tried it without but it will quickly suck fluid into engine)  I used two stroke oil for fluid.  Works quite well...very sensitive...and seems accurate...still might modify it to have 4 separate reservoirs...I think this will reduce the sensitivity to a more practical level.   I spent about 20 bucks but had stuff like plywood, zipties, screws and hardware lying around.

[seanbarney41]

...the carb fittings and detail of how I used main jets for restrictors...

[hapakev]

how did you get those jets down the tubes like that? long screwdriver?

[seanbarney41]

it's actually a splice in the tube, put the smaller threaded end in the end of one tube, then I used a razor blade to thin the inside of another piece of tubing so it would fit over the fatter part of the jet.

[ksmith0034]

What are those long fittings you are using?  I know you said you got them from Z1, but I can't find them.  I made mine by using a 5mm die to thread one end of a brass connector but it's pretty short.  I think those long ones would be much easier to use.

[seanbarney41]

yeah, the long length is nice...
http://www.z1enterprises.com/detail.aspx?ID=3263

[ksmith0034]

Awesome, thanks.