Topic: 977 hondamatic carburetor

[shar001]

hello guys,
  i just bought this 1977 cb750A and this is my first bike. i have most of the parts which comes with it. my main concern is the carburetor. i'm not sure this carburetor is the right one( i tried to looks pictures online, but there is no pictures of the carb by it self)
 my 2nd concern is, if my carb wasn't the right one, is cb750K carbs will fits and what are the adjustments i should do to make it work.

(the carb i have right now is gunked and i dip in the basket of gas. hope i could get it cleaned)

i needs some help to get this bike running...please help

[raymond10078]

Welcome to the SOHC4 Hondamatic group!

Pics of 77 carbs can be found on the internet - at least two for sale on ebay right now.

I recommend that you download the service manual from this site (see the links at the top of the Hondamatic page).  The manual has very good pics, too.

The 77 carbs are PD44B, and will be stamped on the carb.

The K carbs won't fit - the throat is too large to fit the A carb holders/rubbers.  If you can't rebuild your carbs, the only viable option (outside of just buying another set of A carbs) that I know of is to switch to 76/earlier K carbs or Yamaha Seca/Maxim 650 carbs, with new holders (the 76/earlier holders work with both).  You will lose the idle solenoid/control in this swap, though.  That means getting used to giving the bike a little gas when in gear to keep it from stalling.

[shar001]

Thank you very much for fast reply. I just check the carb model and it's PD 42B AG. So I guess, I have to find a another carb. I checked ebay, and they are really expensive. Any ways thanks. Hope I can find one soon.

[raymond10078]

A limited search indicates that the PD 42B is from the 78 K bike.

[shar001]

hello again,
 come back with a bigger problem. i ordered the carburetor and wire harness to complete the work. when i try to remove the spark plug, #2 spark plug half of the thread broken inside. i check the rest of the spark plug,and all the ceramic pieces are came out exept the tip and half of the tread. (this bike was sitting for 26 years)
  i did little reserach online and seems to be, i have take apart the head. so my question is,
* is there any other way around without taking the head?
*if i have to take the head apart, i needs to grab all the parts in need( gaskets n ect.) is there anybody who can help me with a list of all the parts that i needs to put the head back together and some help full tips good to know.
*****i think this might help another guy who disembles for first time.
thank guys, hope i'm not bugging so much.

[raymond10078]

Others may speak up . . . did you download the service manual?

Otherwise - the head on the A is the generally the same as the non-auto bikes.  These types of questions are better asked in the sohc4 thread - you'll get better responses (for these common to all bike questions) there.

http://forums.sohc4.net/index.php?board=2.0

[salukispeed]

Might want to give the plug holes a shot of  rust buster to give it  lots oftime to work. I have never run into a broken plug that broke off part way  so It will be tough to suggest any solutions. I have used a product called KROIL that seems to be the best rust buster ever. and some people are having good luck with 50/50 dexron trans fluid and acetone. . Time seems to be the major factor in having sucess.  Good luck and slow and careful will be the best solution.