Carb sync tools

[Kool_Biker]

In the excellent ICOA Tech Tip chronicles, in the 'Carburettor Adjustment: The Right Way' article, the author mentions TWO tools for synchronising the carbs.

1. 07908-42201000, and 2. 07908-4600000

Tool no 1 we all recognise and I already have.
However, tool no 2 is NOT mentioned in the official Honda manual for the Z, and is not recognised by the likes of David Silver Spares here in Europe.

Is this vital (yes, it was a pain to adjusting carbs 5&6 with tool no 1 as the author mentons), and if so, please, where can I get one?

Cheers, Aris

[spencer]

If you mean the short carb sync tool, you are one digit off in the part numbert. I got mine from Honda. I assume it is still available.

[oldschoolcarbs]

Aris, the chief symptoms of poor synchronization are 1) trouble maintaining a smooth idle, 2) slow to return to idle after revving, or 3) the idle speed tends to increase as the engine reaches max operating temp.

If you pull to a stoplight and the idle stays high and then bogs down for a time and and then drops suddenly, your synch is off. Or you're out on the highway and the engine speed stays high while shifting.

If you've got a rapid and smooth return to idle in all situations your synch is fine.

Here's a trick I learned form a guy who used to race cobras and had to switch carbs often and in a hurry. Needless to say time and accuracy were of equally paramount importance: Get hold of some thin and VERY straight wire. Use the idle adjust and synch screws to open the throttle butterflies so they're all further open than your wire diameter. Now start adjusting them in proper sequence just until the butterfly contacts the the wire when you hold it exactly over the bypass holes. Be very careful as it's easy to pinch into the wire and thus lose accuracy but if you develop a fine touch for the proper feel it's foolproof. This works best on the bench but it can be done in situ.

Also be aware that on the cbx you MUST work from the center out. The throttles are linked in such a way that turning the #4 synch screw moves the #5 and #6 throttles sympathetically; likewise #3 (main adjust screw) affects #2 and #1 in descending order.

I hope this helps.

Jack

[Kool_Biker]

If you mean the short carb sync tool, you are one digit off in the part numbert. I got mine from Honda. I assume it is still available.

Aha, Spencer, great. This makes sense!
In fact I was not one digit off ... there is a typo in the ICOA Tech Tip Chronicles (at least the version I have which is a few years old) and that's why I got lost.
Good stuff, thanks a lot.
Aris

[Kool_Biker]

Jack thanks, all this makes sense and adds to the collective wisdom of the Forum
Cheers, Aris

[Carl]

Does anyone have a picture for this carb tool part #07908-4220100 ?

[spencer]

Here is a picture of the Honda Tool. I don't have one. Instead, I have a Motion Pro tool, which is pretty much equivalent. I got this picture from the CMS website. This tool is probably also still available from Honda. I think I'd rather have the Honda tool, although it probably is no better than the Motion Pro tool.

[Jeff Bennetts]

Another very simple way to bench sync the carbs is with a depth gauge, check the distance from the throat of # 4 carb (the base carb) to the butterfly then match/adjust the rest of the carbs to this measurement.

[Kool_Biker]

If you mean the short carb sync tool, you are one digit off in the part numbert. I got mine from Honda. I assume it is still available.

Spencer
I have tried to order one over here in Europe, and was quoted delivery in July ... So I will make my own.

So please, can you provide me with the only two important dimensions:
1. Length of column, very top including the handle ring, to very bottom, including flared end.
2. Length of handle where the P/N is inscribed, to its mounting ring.
All the rest are OK as I already have the larger one.
Thanks!
Aris

[spencer]

I'm sorry it took me so long to get these dimensions. I am including three dimensions because I was unsure of exactly what you wanted with one of them.



If you can't get one in Greece, you could order one via the internet from an American company, and have it shipped to you. It costs less than $20, plus shipping. I don't know how much international shipping is, but for something this small, it can't be too expensive. One place you could order from might be:
http://speedsupplies.com/partslisting.a ... ategory=HN

[spencer]

OOPS! I checked their shipping charges. $47.50 is too much. Maybe some other place will ship at a more reasonable price, otherwise, I guess you can go ahead and make your own.

[Kool_Biker]

I'm sorry it took me so long to get these dimensions. I am including three dimensions because I was unsure of exactly what you wanted with one of them.

Spencer thanks! And I promis this will be the last time I describe mechanical dimensions the way I did just because 'Aperture' my photo app in my Mac will not do draw overlays
The tool seems quite easy to make, so I will have a go at it and report back.

But thanks so much for a professional response to a clumsy question.
Aris