Manometer question

I'm sure it's on here, but I can't seem to find it. I've seen a thread on how to build a manometer, but can't seem to find it now. I'm also not sure on how to use it correctly. I've never found a step by step thread on that though. Any help would be much appreciated.

 

I ended up finding the threads on how to make one, but still not sure about the proper use of it. Like where to hook it up at. Any help?

 

Depends on which variant you're talking about. If it's a "two-piper" then it's used to balance any given pair of carbs. For instance, 1-2, then 3-4, then 2-3; you hook it up to the vacuum ports on the intake manifolds.

You'll need to set your petcock on PRI or use an alternative fuel source when you're using the port the petcock is normally hooked to.

 

That helps a bunch and yeah, I'm using the one with two tubes. I'm having trouble finding vacuum restrictors. Are they must have or will I be ok without them?

 

I use the two tube method too... but I sync 3,4 and then 3,1 done.

 

Hey Bill, I'm curious. How do you sync 4 carbs with that method?

 

Connect the manometer to the suction tubes/hose barbs for 3&4.

3 is not adjustable so you use the adjuster screw between 3&4 to make 4 = 3.

remove the manometer and re-plug the suction tubes/hose barbs.

Move the manometer to the suction tubes for 1&2.

Then you use the adjuster screw between 1 &2 to make them = each other (whatever that is)

Then you use the adjuster screw between 2&3 to bring the pair 1&2 and 3&4 to match each other.

so the one between 2&3 brings up the two carbs on one side or the other, depending on which way you turn.

When all the readings are the same, you're done. Replug all the suction tubes/hose barbs

Remember to keep the RPMs around 1300 or so while you do this so all the adjustments are done at the same RPM.

You'll be happy.

Gary

 

Thanks, KA1J. I know that method, but I was asking about Bill's. It's different.

 

KA1J,
Its my understanding that 2 is the only one that is not adjustable.
If Im wrong I would love to know, (the next time i sync im trying your way, it could make my bike run better).

I connect 3 and 4 to my homemade 2 tube manometer. ( its a 12 ft tube nailed to a board with 10w 30 motor oil in it with the tube cut to equal lengths of course). Dial these babies in until they are even on the board somewhere.
Plug number 4 back up. Run the hose to 1 so I am syncing 1 and 2 together DONE.
This method seems to work.
Please correct me if different methods work.

 

Well I made the manometer and attempted to sync. Got em all pretty close, but my idle varies. On top of that it dies instantly if I give it throttle. I'm sure it's a simple adjustment, but I'm a noob to this. Ideas?

 

Did you adjust the mix screws yet?
If you did not, (and dont have the colortune) there is a old school way of adjusting the mix screws.
You get the bike warm and idling. Start with any carb i guess and start turning the mix screw until the idle climbs, where it stops climbing is where you stop. Im sure someone will add to this. Adjust the main idle screw to where it idles (normal) and on to the next carb mix screw. This variation of adjustment works best (ive found) if you have new spark plugs.

 

K I think that makes sense to me. I pulled my spark plugs and they are black. So now I'm wayyyy rich when I was wayyyy lean before. I'll try that and see what happens. Thanks.

 

I changed the spark plugs and I seem to be in the same boat no matter what I do. All the levels seem good, but it's still F&@#ED. Should the idle screw have to be turned really far out? That's the only way I can seem to get it to idle decent. Guess I'll go try again. Been at this for over 4 hours now. I can't seem to get this for the life of me. I really don't wanna have to take it to a shop and spend 400 bucks when that's how much I have in the whole bike.

 

2 IS adjustable.

2 adjusts with 1 just like 3 adjusts with 4.

your only turning one screw. but 2 is definitely moving. and needs to be adjust with 1. not 3 or 4

i adjust one side of the rack. snap the throttle and readjust. it takes 3 or 4 times before the adjustment comes back with each throttle snap. meaning, adjust the carbs. snap the throttle to make sure the fluid is still level between the two carbs after adjustment. then i do the other side. same procedure. then i plug 1 and 4 off. and do 2 and 3. same procedure.

i have a 4 tube setup.

my first two times trying it. i adjusted and rode the the bike. the idle really sucked. then i started using the snap throttle method to make sure the adjust was still there when the throttle was released.

 

Snowwy,
You are making TOTAL sense. The way ive been doing it is why my idle sucks. Thank you.

 

Is it possible that my idle screw is messed up and that could be the cause of the problems? I have to crank it all the way in to where i can't even do it with my fingers it's so tight before it will move the throttle. Not sure exactly how the idle screw works, but it definitely doesn't seem like its working right. I'll try snapping the throttle and see if that helps. Thanks again.

 

When you are adjusting 2 and 3 what are you turning?

 

I've turned both ways. I didn't mention that I have a pvc intake manifold. I'm gonna chalk that up to 5 hours of working on the damn thing which turned my brain to mush. I think I've got the method down to a science. The problem seems to be a matter of adjusting how much air I have coming in. I've tried reducing the air coming in. I ran super rich when I tried that a couple ways. Running just the pod, I seem to be super lean. Not sure how to find a happy medium. Also I still think my idle screw is f'd in A.

 

You need to properly check your float levels and do a careful bench sync before the carbs go back on the bike. When you bench sync you can set the main idle screw so it has some adjustment range.

Just cranking on screws will put you so far into left field you'll never get it right.

 

I've double checked my float heights and they're within a millimeter or so of 17.5. I've been doin my bench syncs using paperclips. Is that an acceptable way or is there a better one? I haven't really paid enough attention to the idle screw when doin the bench sync though, I think you may have solved the mystery there. I'll give it another go this weekend. Thanks a bunch.