Carbtune Pro

Does anyone have experience using this particular manometer? I bought one a couple weeks ago, and can't get it to read anything unless I'm well out of idle range, 5K or so. Is there a particular trick I'm missing or something? I've verified it is hooked up correctly, and my tubes are not kinked or pluged.

 

I've got one I used on the 650G this past weekend along with colortune plugs.

Did you install the restrictors in the lines ?

 

The restrictors are in on the manifold side. I've checked and re-checked everything according to the book that came with it, but am at a loss.

 

You try it on both bikes ?

 

I haven't. I guess that would be a good way of figuring out if it was the instrument or the bike. Guess that means I'll have to pull the Virago out from it's winter slumber and get the battery charged up.

 

I think you may want to try it without the restrictors.........

 

I was thinking about taking the restrictors out, but everything I've read on the subject says you have to have them. I'll give it a shot though.

 

I don't have your model, but my Motion Pro 08-0411 needs to be calibrated before each use.
It has a calibration manifold (CM) (6-way Tee with one blocked-off).
Attach a short piece of vacuum hose to the calibration manifold (CM) to cylinder #1, then attach all 4 vacuum hoses from the manometer to the CM.
Calibrate the manometer with the engine running at idle check and adjust the manometer so that all four channels are reading the same value.
Once calibration is completed disconnect from the CM and attach the 4 lines onto the engine manifolds to check the sync.

 

I have the Carbtune pro and had a similar experience on a 750 SECA. Had just gotten the bike running again, but it wouldn't idle right. Hooked up the carbtune and it would indicate about nothing unless I reved it up over 1500. Made some adjustments but didn't spend much time on it, though I might have gotten it a bit closer to being balanced. After I adjusted the mixtures (per recomendations here) and got it to idle (almost) right, I hooked up the carbtune again and this time it worked great.
So, you might try color tuning first, and then give it another go.
Don't know if that helps, but that's how it worked for me.
Oh, and I am 99% sure there is NO calibration required (or even possible) to do on the carbtune.

-Geej

 

You are correct!

 

I use this as well. Leave the restictors in otherwise you'll have nothing but problems.

I've always found that you have to let the bike warm up and come off choke before you get any decent readings.

TIP1: Always use a fan in front of the motor when you are running it stationary for any length of time. I use an old fan blower motor out of a furnace. Birdcage type that throws a lot of air.

TIP2: Buy a small plastic hose tee about 1/4 " and about 18" of rubber hose. When you take the tank off the bike use this to connect the tank back up to the bike. Put the tank in prime positon and use it as your fuel source.

That's it for now.

 

Follow up:

Well, a few things have developed since I made this post. Just thought I would share my findings. As it turned out, I had two weak spark plugs, which is odd because they were brand new. Once I changed them out, I still wasn't getting much on the carb tune, but discovered that turning it upside down gives you an entirely different/higher scale to work with. I adjusted the colums and idle until I was maxed out on that scale, then flipped it over right side up and continued tuning with each slug about an inch and a half or so up the tube. So, long story short, if you can't get a reading right side up, flip it over. It becomes able to read a much higher vacuum than it can right side up.

 

I had the exact same problem as you and also did what you came up with. It seems to work okay. However one thing I did find was if I rode the bike for an hour and then tried to sync I was able to get more vacuum without the YICS tool installed. With the YICS Tool, The vacuum was much less and hard to read as you found. So i synched without the YICS tool which definitely helped. This weekend I"ll try again with the YICS tool and see if I get a better result after riding for a while.

I have the Carbtune II by the way.

skm

 

I'm not sure about the YCIS. Both of my XJs have been non-YICS bikes. So, I can't really comment about it. Wouldn't want to lead anybody down the wrong path.

 

Thank goodness for the search feature. Turning it upside down was a game changer.

 

That may work, but shouldn't be necessary. The carbtune can be dis-assembled and then cleaned (the instructions tell you how to do it); it sounds as some residue may be creating friction within the tubes or on the slider pins.

 

This was brand new wrapped in plastic. One side up, no movement unless I revved it up a few k or ran without the restrictors. Upside down, it works as advertised. And there's a zip tie bracket to hang it upside down, so it seems a feature, not a bug?

The manual says:
"To get a reading below 8cmHg remove the plastic cable clip from the slot at top of gauge and insert it into the slot at the bottom. Push cable clip into slot from front of gauge. Hang the Carbtune Pro upside-down.

"Ignore the scale figures. Zero will now be around 16cmHg on the scale but the full width scale graduations will still be 2cmHg. Absolute values are not important. Comparisons are important."


That said, maybe my intake boot outlets are somehow restricted?

 

Well, below 8cm Hg = below 80mm Hg, which is a really low vacuum reading.....for example, the XJ650 / 750 engines have a specified idle vac readings of:

XJ650 all (x. Turbo) and XJ700 air-cooled:
180mm Hg = 18cm Hg
7.09" Hg
24 kPa
allowable difference:
5mm Hg
0.197" Hg
0.667 kPa



XJ650 Turbo and XJ750 air-cooled:
185mm Hg = 18.5cm Hg
7.28 +/- 0.394" Hg
24.7 +/- 1.33 kPa
allowable difference: not specified


I've never had a problem with the Carbtune models not giving a reading while being in the upright position, unless there was some type of contamination within it or a vac leak somewhere (either in the intake system or in the rubber tubing). Actually, I've never even tried using it in the upside-down position.

 

Sorry.
I tried a manometer and ended up very angry with it.
Bought one of these
https://tecmate.com/carbmate/
And have used it dozens of times with a huge sense of relief and a smother ride.
And yes... Not too helpful but I thought I'd pass it along.

 

I used home-made ones in the past with ATF or whatever and they did the job, so I'm comfortable with the theory. Starting to suspect there's just something going on with the intake section on the bike. I'll work it out - one thing at a time. Glad you found something that works well for you.

 

Of course @chacal was right. I'm updating my thread ( https://xjbikes.com/forums/posts/672716/ ) but I wasn't in the right ballpark to be getting good pull. Once I got my mixtures a bit more dialed in, right-side-up was the way to go. The work-round still revealed a bigger problem.