Henry Abe airbox (KZ650)

Hi all, about a month ago I picked up a 1979 Z650 (first bike since riding 50cc's). It runs, but is hard to start, and I have to play a little with the choke to get her warm and running. The former owner told me it's been standing in a barn for a couple years, but the carbs were drained and cleaned not too long ago.

My plan for this bike is to firstly get her running right and then swap out a few parts for looks and such. But I was wondering if anyone has any experience with the Henry Abe type of air box, and if it's a lot of trouble to get the bike to run right with it compared to the stock airbox?

Pods were a no-go for me, they look okay, but the quality of most of them is "so-so" and the tuning afterwards is just not worth the hassle imho. Would this airbox be just as bad?  ​​​​​

If you remove the stock airbox do NOT hurt it!  There are plenty of folks that would love to ditch their aftermarket pods, Abe, etc. filters and install a stock airbox.  Can you guess why?    Ed

wrote:

...and the tuning afterwards is just not worth the hassle imho. 

You said it right there.  I completely agree that it's not worth the hassle.  Both pods and the bread box are likely to require messing with jetting.

It looks like you still have the original air box, so consider yourself lucky.  You should definitely replace the rubber boots between the carbs and the box with fresh soft rubber is you haven't already.

I agree that it's a pain to get the carbs on and out with the air box, but it's worth it in the end.  I just put the stock box back on my Z1R and it runs better than it ever did with pods.

Ed: If I'd had to make a wild guess I would say because of tuning issues

I do have access to a car mechanics shop (in the family) and all the tools that come with it, including an exhaust gas analyzer (which I've heard can come in handy in this case). I'm personally not the worst mechanic myself, but a long way from the best. The leader of the shop on the other hand has about 35 years of experience in this field, so I guess it wont hurt to try.

I will make sure to take notes of how the tuning is currently, and also make sure not to damage the original airbox. I have already ordered the henry abe box, so if it doesn't work out, I will just put the stock airbox in and tune it back. But the looks I'm planning for with this bike is to eventually ditch the side panels and open up the space in between to make it more "streamlined" along with other modifications.

Do you have any pointers about where to start out with the jet sizes and such for this setup? Also I'm not 100% sure if the exhaust that sits on it now is the original one for this bike(?) 

 

That Henry Abe would be a similar jetting setup as individual pod filters, there is not much volume to draw from like the OEM air box. The OEM air box straightens out the air flow before getting to the carb mouths, with that short "air box" and pods you get turbulent air flow, side wind flow, moisture from any rain etc. You don't get those same circumstances with a engineered stock air box.

There should be a foam filter all the way around that Henry Abe.

That exhaust is not stock. With the exhaust and the Hernry Abe start off with a 15 pilot jet and a 110 main jet, depending on if the air screws need to go all the way in you may need a 17.5 pilot, main should be good unless rich then maybe drop down to a 107.5 - Just depends on how its running.

Thank you! Just the answer I was looking for 

I know there is supposed to be a foam filter, but I haven't gotten around to finding something that will fit yet. I bought the bike under a month ago, and it's currently sitting in the family car-shop while I live 6 hours away planning how I want to build the bike and gathering parts for it.

I have seen some people using duct tape or something similar on the inside screen of the henry abe filters (on the sides) to avoid problems with cross-wind.
Could you point me to a good site to find pilot and main jets for this bike? 

Again, thank you

Any foam? Upholstery shop? Furnace filter foam?
I bought my 1st ABE bread box from "Beck-Arnley" in 1978 for $19.99. For the 1000,
Then it cracked my paint job side cover up by the gas valve from vibration. Because the air box rubbed at the plastic side cover.
Old pic copied.
 

I'll probably find something in a shop nearby to use. I'll be sure to check the fitment of the box before painting the bike now, thats for sure! But I'm thinking of ditching the side panels and clearing the triangle beneath.

Still need a reliable site for main and pilot jets. Does anyone the part nr.? The carbs on the bike have "MIC" stamped into them, so I guess they are mikuni's. But since I dont have the bike at hand it's hard to check

You have 24mm Mikuni carbs. Only use Mikuni brass ( jets, float needles and seats etc). Jets-R-us, Dennis Kirk, Z1 Enterprise, Sudco, are just a few. 

We only have digital copies of a 1977 model and for the 1981 model. The ‘77 says 100 main and 16 pilot. The ‘81 says 102.5 main and 15 pilot. That would be a close starting point. Pull the carbs and see what they have in them currently. A good thorough cleaning is highly recommended. The only correct way to do it is to break the carbs down off of the rack. Keep all the parts with the specific carb body. Disposable Tupperware bowls work great. Mark them carb 1,2,3,4, and keep all of the parts respective to each in the marked containers.

EDIT: Cylinders are numbered left to right sitting on the bike 

I got this service manual from the owner when I bought the bike:



He also mentioned he has like 3 boxes of motorparts I could get for about $200, I'll check if there is something I can use.



Thanks for the quick replies guys, really appreciate it 

UNI brand sell automotive air filter foam in bulk sheets. I replaced the foam in one of those units once and that is the stuff I used, it is fuel and oil safe.

#BF-1 is a green fine grain foam : 5/8" thick x 12" x 16" - A perfect thickness for that style of thin "air box". You can order it thru any local dealer or probably find it on Ebay.