I'm shocked it actually works! Home made carb balancer
 

Ok, I have been playing around with the carbs on my bike for the last week. Was going to borrow a friends carb sticks this weekend (the old mercury filled ones). Last night got home early from worked bored so set about making my own manometer. About $5.00 later of 3/16 ID clear tubing, filled with the same 10/40w engine oil I use in the SH.
I hooked this up to my already installed vacum take off lines. Started the bike up not really knowing what to expect? and what do you know this worked like a treat! One side slowly crept up about 8 inches higher than the other side. Adjusted the the sync screw so each side was even. Small adjustments made quite a difference. The balance stay pretty even from idle up to 4000 rpm less that 1/4 inch.

I had no frothing of oil. No air bubbles anywhere. Balancing was real simple. Afterwards I noticed that balancing the carbs had made my idle pick up by about 200 rpm, so had to lower that back to 1150 rpm. No huge power gains, but want I do notice is the very low rpm driveability is so smooth now. I can pull away from the lights with just 1500rpm showing and fueling is perfect. Splitting lanes between cars with very low rpm's is a breeze now.

I highly recommend to do this. I'm going to double check this with the mercury sticks, but honestly don't see how it could get any better?

I never used any type of air restriction as others have mentioned. Just attached the 3/16 ID tubing to my vacum lines with a brass conector.

The cheap balancing tool has worked great for me too! My carbs were way off after working on them. So much so that when adjusted the idle settled down to the point where it killed itself.

Got the idea from someone on the forum...
$1.55 Carb Sync Tool by Marty Ignazito

Never actually used the lines in the yardstick (I think it was just a cheap piece of material at the correct lenght), just adjusted till they were even.

I use transmission fluid just because the red shows up nicely. it's nice not spending a hundred bucks for something so easy. :)

I made that cheap one iwht the ruler awhile ago but have not used it yet. I got the second nipple from honda last week and habve not worked out how to seal it once its on. or how the hell to get the stopper out.

Use an old small piece of hose and put a screw on the end of it... You can see how I did it at the lower end of this pic...

Attachment 26080

Yes thats kind of what I did. I attached a longer piece of tubing and run it over to the choke knob, then installed a tee in the gas tank vent line and also routed that to the same spot. I screwed allen heads bolts all the way flush to the face of the tubing with some small clips.

Now to sync the carbs just remove two bolts, attach two brass conectors, and balance. To reach the adjuster screw I did not even have to raise the tank, 7mm socket, small flexible knuckle, 2" bar, then screwdriver attachment. Easy to see and adjust.

Try it, I'm glad I did. This forum constantly surprise's me.

7mm socket and extender is how I do it as well- I have to flip the little switch on my ratcheting wrench to change direction for minor adjustments, but it's so easy to do I didn't try to figure out another way. And I screw the heads flush too :). That pic I had for something else...

What do you mean you route to the gas tank vent line? You mean the petcock? Or is there some reason you're trying to create a suction in the tank... ;)

Oh wait, I get it now- you ran a line from the right side of your bike to the left so they're both on the same side. That makes sense now.

hey I just did mine yesterday too! I used the two-bottle method, worked good and hell yes did a little turn on the adj. screw make quite the difference!

hey I have a question for the guys in this thread. I slotted my "D" shape fuel mixture screws so I can use a flat head and made them 2 3/4 turns out (too much, I need to reduce it to 2 1/4). Problem is, now installed those screws are damn hard to get to under the carbs. anybody have any tips? pull the carbs back out?

JC Whitney is where I got my carb adj tool from, but that was 10 years ago.

Fish

Motion-Pro-Pilot-Screw-Adjusting tool
 

Motion Pro Pilot Screw Adjusting Tool - Dirt Bike Motocross - Motorcycle Superstore

Just google the tool, lots of differents sellers.

This one looks really nice http://cgi.ebay.com/ebaymotors/Motor...Q5fAccessories

ouch, expensive. I'll just take the carbs out or at least remove them from the boots to turn them sideways.

also, not trying to thread jack but I've got a quick question.

I noticed that my bike was running fairly well all day yesterday after the sync, then it started getting dark and quite a bit colder out and my bike would "carb-spit" and pop significantly more on ~1/4-0-1/4 throttle transitions than earlier in the day. is this a lean issue or a fuel issue?

I have that issue too. Whenever it's about 60 degrees or less, it will spit occasionally. Runs great any other time. I was able to fix that by raising the needles 1 position. However, the bike felt soft. Just didn't feel as strong. I just decided to live with it. My thought is-why sacrafice power and performance to fix a cruise issue? I know temp, humidity, atmospheric pressure and the like have an effect on things. I'd be lying if I said I knew just what they are though .

Where does it attach on the front carb? I see on superhawk996 to attach "the fitting" to an allen head screw. How does that work?
Thanks
Torie

The easiest way is to buy a boost joint for it (part #16214-MB0-000) This is the same joint that is in your front cylinder and on lots of other Hondas... Then replace the alan head screw with the boost joint and when you're done with the carb sync, cap it off.

Years ago i installed the fitting on the front cyl and ran it over to the left side. Simple to hook up my vacuumed dial gauges ans adjust it quick then cap them off.

Thanks guys! 7moore7, where is that part number from? Honda?

Why does syncing carbs require accessing the front cylinder. I assumed that both of the "do-it-yourself" vacuum lines (aka clear tubing) would attach to vacuum lines of each carb.

Thanks again for all of the answers.

Torie

Nope, you attach the sync gauge to the intake area at the base of the head between carb and head.

Yes, it's a Honda part number... it's actually used on a lot of their bikes... including the rear cylinder of our bikes. You are correct in that it attaches to the petcock vacuum line of our bike... but in the front cylinder they have that weird alan head screw as there is no vacuum line there. From my understanding of it (and the way that I do it), it is easier to buy this part and put it in the front cylinder as well, rather than remove that screw every time you sync your carbs. The location is kind of mirrored from the rear cylinder, in between the carbs and cylinder head on the right side of our bikes like thumper said.

So, you have two attachment points where you sync the carbs... the rear cylinder gets the t-connector which you install into your petcock vacuum line and the front cylinder is just that booster joint part # that you can order from ronayers.com or hollisterhonda.com.

Going back to your question... the do-it-yourself clear tubing and professional tool tubing attach to the same points on the motorcycle (they just read the vacuum a little bit differently). The do-it-yourself tool doesn't give you an actual pressure reading, it just indicates when you have equal vacuum signals. The pro tools actually tell you what psi you're getting i believe... and can read 3 & 4 cylinder motorcycles ;)

Excuse this if it has improper grammar or doesn't make sense... beer was cheap tonight haha!

Funny story...I drove an hour to the local Honda dealer for the boost joint ($4.99) and a stock filter ($79.99 - Robbery!!). I couldn't find a yardstick anywhere so I made my own with a piece of lathe and a tape measure. Anyway, I went out to install the boost joint and behold it already had one with an extension over to the opposite side of the bike. Obviously it has been synced before.

So a question, I have some Amsoil 20-50 oil which is red. Could I use this or is it likely too thick?

Thanks
Torie

That's pretty thick even for Arizona... for Canada I'm surprised you can pour it ;)


And I actually don't even use the lines on my yardstick... I just get the fluid level to be even. Not entirely sure you why you need the lines to be honest. Unless you're really bad at eyeballing stuff. Good luck with the assembly!

Vacuum booster part number?
 

OK guys, I've read this from front to back....where is that part number. The Honda shop here in Anchorage just looked at me funny when I tried to explain what I needed, :p



FOUND IT: JOINT, BOOSTER (16214-MB0-000) from ronayers.com. silly me.

Honda part #16214-MB0-000

It's an OEM part number, so your dealer should be able to order it, or you can grab it online somewhere like hollisterhonda.com

What size brass T do you guys get, and where do you attach it exactly? Sorry, had a difficult time understanding that in the reading above...

Thanks!

Pretty much all Honda inline fours have a 2 inch black vacuum hose with a green or black cap on the end.

Each hose is connected to the vacuum port at the base of each cylinder which makes syncing the carbs much easier on the 4s.

So next time your on Ebay take a look at any of the crapped out inline fours by Honda selling for parts and I bet you could get all four lines, spring clips and caps shipped to your door for 5 bucks or less, stick one on your hawk and sell the other three here for 10 bucks a pop!

A question on the homemade sync tools...

Don't both the vacuum tubes need to be the same length with the exact amount of fluid in each line to get accurate readings, just a thought?

SIRR1

If you're trying for a specific number, then yes... But since you aren't adjusting four cylinders, all you need is balance between the two, so then no... Get the balance correct, and keep going until you get the "swing" as small as possible, and then a bit further...

The carb balance tool is setup to automatically be the same length.

One long tube. Bend in the middle. So now you have two tubes that are the same length attached at the bottom. Run this tube along a straight edge and set it vertically, that way when you put fluid in it and it automatically levels out so that there's the same amount in each half of the line.

The balance process is not done by adjusting one tube to match the original signal like on an I4 with this cheapo setup. You are just adjusting it so the fluid doesn't travel down or up either end of the tube. Effectively creating a balance of vacuum between both cylinders without actually knowing what the signals are.

Hey guys. I have a question about this. From what I am reading all you basically do is get a T fitting to splice into the line going to the gas tank for the rear cylinder. But what about the front? Is there a fitting you can buy to screw into the front cylinder? I feel like I missed a thread about this and am playing catch-up. Thanks guys!

Well, you could read THIS thread... Since the part no for that part has been mentioned not one, not two, but a whole of three times in this thread alone...

I might be grumpy and mean, but I still say it makes you look pretty dumb asking that question five or six posts below the last time... It kind of proves you didn't put any effort in reading yourself pretty blatantly...