Author Topic: Carb's are finally done! (Read 3676 times)

toytuff · « **on:** August 31, 2011, 07:09:13 pm »

Thought I would never get these back! PD 41's for the 1977 CB K.

I dropped these off the first week in May. Just got them back today. I know, I know, it was a long time. The automotive shop was also a Honda dealer until 1988. Dennis still does crab work but only on Saturdays and that's if he doesn't have towing work or back log in shop. He also had seven (7) sets ahead of me.

Completely disassembled, cleaned, all new everything, set floats and sync cabs with a feeler gauge . No need to use a carb sync. Told me he has always done that with no issues ever. I'll go with it.

He has 30 plus years, I have zero.

Cost? $125.00

At any rate I know we love pics.

tt

Johnny5 · « **Reply #1 on:** August 31, 2011, 07:58:44 pm »

Crab work? Gross.

haha

Nice looking carbs! Now get them on a bike!!

johnrdupree · « **Reply #2 on:** September 01, 2011, 07:04:17 am »

Nice rack

. You'll still have to sync the carbs once they are on the bike, though. Differences in cylinders will cause differences in vacuum levels and will need to be equalized for a smooth idle. It's not a tough job and you're probably 97% of the way to fueling perfection.

~john

jneuf · « **Reply #3 on:** September 01, 2011, 07:33:52 am »

Look great! That seems like a reasonable price too...

Regarding the sync, I'd think you'd still want to sync them when you get them back on the bike. It isn't a difficult job, and it would be good peace of mind.

Perhaps he did sync them bang on with the feeler gauges....it could be possible! However, for some reason that just makes me think of a lot of the old school car mechanics that I've met that claim they can set timing by ear, and do it better than a timing light can. After one of those ear timing sessions, I saw a freshly built engine have holes in it's pistons

bollingball · « **Reply #4 on:** September 01, 2011, 07:42:18 am »

Where is the throttle return spring?

Is there any thing inside missing?

vames · « **Reply #5 on:** September 01, 2011, 08:06:00 am »

So this guy took four months to rebuild a set of carbs and charged you $125 for the privilege?

You know you could have done it in about two hours with about $20 worth of parts and chemicals, with every bit as good of an initial bench synch, right? He probably did a good job, but that's a loooooooooong time.

cookindaddy · « **Reply #6 on:** September 01, 2011, 08:19:55 am »

They look great in the pictures. Very shiny! Neat trick with the twisted wire hose clamps. Don't cut yourself on them.

Yes, the throttle return spring is missing. It should go where shown below. The K8 had the return spring on the big shaft but yours is a K7.

Yes to sync on the bike.

Probably not to two hours and $20 by yourself

I spent almost what you did just to buy the gasket kits and the accel pump and to do a thorough job took me about a week on and off, but it was my first time.

Put em on and get it going!

bollingball · « **Reply #7 on:** September 01, 2011, 09:45:55 am »

If you were not in a hurry the time does not matter.I don't think the price is to high at all They are good and clean on the outside probably inside too. All you have to do is remove the #4 carb to get that spring on. Not hard to do. Just hope he has it and he should do it. If it was not on there before he should have told you.
K7 has the same spring as the K8. The only difference I know of is the jets and that may be just on the F model. One thing you want to make sure of is the choke plate screws are peen ed or have lock tite on them.

You do want to sync them or it will never be spot on.

toytuff · « **Reply #8 on:** September 01, 2011, 03:15:37 pm »

Thanks guys. I have a new spring in package. Previous owner had tweaked the other one.

He had seven (7) sets ahead of me and only works on carburetors on Saturday. He runs a reputable garage and towing service along I-40 between Kingman AZ, and Barstow, CA. When you see "next gas stop 100 miles" you know you are in nowhere land. With the heat out here his towing business takes first place.

I didn't mind the wait. To hot to do anything. $125.00 is cheap for me. Maybe down the road I'll tackle a set but for now "get her done"!

They really look nice in person. Starting install tomorrow at 0400 hrs. Gets to hot around 0900 hrs. with a siesta at 1200 hrs.

tt

toytuff · « **Reply #9 on:** September 01, 2011, 03:50:23 pm »

It will be a couple of months before she (Suzanne) is on the road but "YES", I want to get her running.

I have another front end with all OEM parts right down to the bolts and copper washers. Just got my lower fork tube's back from refinisher.

Also scored a complete 405 OEM exhaust for the 1977 model. A real find but I paid for them.

Shissh..don't tell the wife.

tt

toytuff · « **Reply #10 on:** September 02, 2011, 04:59:36 am »

Quote from: cookindaddy on September 01, 2011, 08:19:55 am

They look great in the pictures. Very shiny! Neat trick with the twisted wire hose clamps. Don't cut yourself on them.

Yes, the throttle return spring is missing. It should go where shown below. The K8 had the return spring on the big shaft but yours is a K7.

Yes to sync on the bike.

Probably not to two hours and $20 by yourself I spent almost what you did just to buy the gasket kits and the accel pump and to do a thorough job took me about a week on and off, but it was my first time.

Put em on and get it going!

Speaking of springs can anyone tell me why the black rubber piece you see in the picture would be there?

I have parts fiche (yeah-old school) and it does not show anywhere.

tt

bollingball · « **Reply #11 on:** September 02, 2011, 05:29:55 am »

Now this is getting interesting. The spring and part # you show comes up as a throttle return spring. on this site

http://www.powersportsplus.com/parts/search/Honda/Motorcycle/1977/CB750K%20A/CARBURETOR%20ASSY.%20LINK/parts.html

For a 77 &78 750K I have both sets of these carbs and the spring is nothing like that at all. It goes like cook shows and slides over the shaft. You can see it just behind were I have a #3 written with black marksalot This is a 77 rack. Click on pic to inlarge

toytuff · « **Reply #12 on:** September 02, 2011, 05:44:18 am »

When I started playing with them the spring ran between 3 and 4 carburetors to a hole in the mounting plate just off of the idle screw.

According to my microfiche the part number is correct for the 1977 model.

tt

(arrow is not meant to be sexual and I assume no responsibility for such

)

cookindaddy · « **Reply #13 on:** September 02, 2011, 06:00:13 am »

bolling

With respect, that is not how I showed it. Schroll back to my message. I also had both types of carbs here 77 and 78. I had one like you have apparently two of, with the return spring on the large shaft and the other (which for me was on the 77 bike), had the return spring near the throttle speed adjustment as toytuff has now. Question for you: do one or both of your PD carbs have a plastic breather canister on a short length of rubber hose attached to a vent port in about the center of the carb assy? This for me was the 78. My 78 had this and the return springs as you have them. Curiously, the fiche at servicehonda.com shows for 77 and 78 the type of return spring that toytuff has and not the type that you and I have and it does not show the breather for 78. So Honda documentation is apparently not perfect.

Toytuff - I think the rubber foam is to be stuffed inside the spring, down the hole in the center. I am not sure, but I believe that it provides damping, like a shock absorber, to reduce vibration.

Just clip the spring into the holes I showed on your picture (and you have shown) and you are all set. No need to remove the #4 carb as Bolling suggested because he was thinking I believe of the other type of return spring.

Good luck!

toytuff · « **Reply #14 on:** September 02, 2011, 06:39:33 am »

Inside the spring. It's the only thing that makes sense.

Thank you for the info.

tt

bollingball · « **Reply #15 on:** September 02, 2011, 06:44:23 am »

Cook you are correct I looked at you picture wrong. Good thing is toy does not have to take any thing apart.
About my carbs went back to look at them and remembered the 77 rack is off a (F) model but the springs are the same not like toy's.
If you are talking about the vent just behind the fuel feed line then yes I have that it is on the #2 carb on mine I put a fuel filter from a gas weed eater on the hose to keep out the bugs. I think you can see the brass nipple behind the dark fuel line in my pic. Is this what your talking about?

bollingball · « **Reply #16 on:** September 02, 2011, 06:49:18 am »

Toy sorry for the mix up also I have that hole in the main plate but it is not used.I wondered what it was for now I know. They must use that plate for several carbs and years.

cookindaddy · « **Reply #17 on:** September 02, 2011, 01:52:46 pm »

bolling: yes that is the vent/filter I am talking about. I looked at the 77 750F on servicehonda.com and that does not show up on the fiche for that model either yet you have one and I have one from the 78 750K. Go figure. Anyway, we got toytuff going and explored carb return springs a bit. That's why we are here.

toytuff · « **Reply #18 on:** September 03, 2011, 01:39:39 pm »

Thanks guys.

Speaking of carburetors, what do you use for a in line fuel filter.

I need to run one so is there a particular off the shelf filter or order some.

tt

cookindaddy · « **Reply #19 on:** September 03, 2011, 02:11:09 pm »

You have one in your tank, above the petcock:
http://forums.sohc4.net/index.php?topic=95087.msg1058683#msg1058683
You really don't need or want an in-line. There are other messages and opinions on here about why you don't want to use one of those (airlocks, trouble with gas flow, they don't work as well as the in-tank, etc).

toytuff · « **Reply #20 on:** September 03, 2011, 02:29:18 pm »

Yes, the one in the tank is good to go. Thought I would double protect since the tank has some light rust.

Would hate to plug up those rebuilt carburetors!

tt

illrational · « **Reply #21 on:** September 03, 2011, 03:51:23 pm »

Toytuff totally off topic but i have my carb apart ad could you take a picture of linkage between two left and two right carbs where spring attach linkage...theres two coiled springs i that area and cant remember how the one that attachs two linkages goes on...PLEASE!!!!!

toytuff · « **Reply #22 on:** September 03, 2011, 04:34:13 pm »

Will do. Give me a little time please. House full of people at the moment.

tt

toytuff · « **Reply #23 on:** September 03, 2011, 05:01:01 pm »

Screw the house full of people. Were talkin Honda's here!

Hope this helps.

tt

toytuff · « **Reply #24 on:** September 03, 2011, 05:05:15 pm »

Couple of more. Site won't take five (5) at a time.

tt

Blitzburgh207 · « **Reply #25 on:** September 03, 2011, 05:30:25 pm »

Those carbs look awesome man. Any idea what he used to clean them like that?

toytuff · « **Reply #26 on:** September 03, 2011, 07:02:09 pm »

Quote from: Blitzburgh207 on September 03, 2011, 05:30:25 pm

Those carbs look awesome man. Any idea what he used to clean them like that?

Not a clue. He did tell me he had to soak number 3 carb three different times to get it clean. Had missing seals and other related issues from past owners trying to work on them. Did say they were dirty. Real dirty.

If I had to guess he had a lot of time in them. I'm satisfied and he will get my business again. Some things I'll work on myself but after seeing these he will get any future carb work. $125.00 was reasonable also.

tt

Deacon Thunder · « **Reply #27 on:** September 05, 2011, 05:41:19 am »

Interesting read. I have PD41's on my 1977 CB750F. Been looking for an accelerator pump but have had no luck. Did the guy who rebuilt your carbs replace the accelerator pump on carb#2? And where did he find one?

cookindaddy · « **Reply #28 on:** September 05, 2011, 05:51:54 am »

I think Honda still has the accel pump. I remember getting a quote of about $50-60 but bought mine from these guys for $18 (Canadian):

http://www.vintagecb750.com/products/6/fuel-system (bottom of the page)

What they sent me works well.

toytuff · « **Reply #29 on:** September 05, 2011, 06:00:49 am »

Quote from: Deacon Thunder on September 05, 2011, 05:41:19 am

Interesting read. I have PD41's on my 1977 CB750F. Been looking for an accelerator pump but have had no luck. Did the guy who rebuilt your carbs replace the accelerator pump on carb#2? And where did he find one?

I had one already. I show PD 41B for the SS. PD 41 for K model.

Should be able to find one. According to my parts fiche 16021-393-004, diaphragm set,pump. Same number for K and F model.

tt

Deacon Thunder · « **Reply #30 on:** September 05, 2011, 04:29:00 pm »

Quote from: cookindaddy on September 05, 2011, 05:51:54 am

I think Honda still has the accel pump. I remember getting a quote of about $50-60 but bought mine from these guys for $18 (Canadian):

http://www.vintagecb750.com/products/6/fuel-system (bottom of the page)

What they sent me works well.

I check their site and they are out of stock same as CB750 Supply. You must have beat the tragedy in Japan with your order...I guess?

toytuff · « **Reply #31 on:** September 08, 2011, 12:07:11 pm »

Well guys I finally mounted the carburetors, installed new cables, polished the clamps and installed new OEM screws.

Started to get a little warm in the garage so I'll hold off on setting the tank on her and throwing some fresh fuel in.

Pretty excited about getting this old girl running again.

tt

bjatwood · « **Reply #32 on:** September 08, 2011, 12:12:03 pm »

If it runs as good as them carbs look, you are gonna be one happy Guy!
They look great

(one cool smiley face for each carb)

toytuff · « **Reply #33 on:** September 08, 2011, 02:50:21 pm »

Quote from: bjatwood on September 08, 2011, 12:12:03 pm

If it runs as good as them carbs look, you are gonna be one happy Guy!
They look great (one cool smiley face for each carb)

LOL. Yeah, it fired on ether but other than that who knows how long it's been.

Last license plate was California, 2008. Valves are lashed, points checked, plugs are new and set.

Good to go! (I hope)

tt

toytuff · « **Reply #34 on:** September 12, 2011, 09:37:11 am »

Got the old girl running yesterday. A few issues yet to resolve.

When you apply the throttle it appears gas is running out the float bowl of number two (2) carb. I would think the float would keep gas at a certain level. Might be the accelerator pump seal leaking and filling up the float bowl.

Looks like I'll try to remove the bowl without removing carburetors.

I've done a couple of searches on the noise these things put out. They do make a lot of racket it appears. The clutch did quiet down but the transmission does make some noise.

I'll get the leak fixed then do a carb sync as suggested here.

tt

flybox1 · « **Reply #35 on:** September 12, 2011, 09:51:21 am »

Quote from: toytuff on September 12, 2011, 09:37:11 am

it appears gas is running out the float bowl of number two (2) carb. I would think the float would keep gas at a certain level. Might be the accelerator pump seal leaking and filling up the float bowl.

only when you apply throttle?

i'd try tapping on the bowl with the plastic end of a screwdriver to "unstick" the float.
its a scientifically proven method to fixing overflowing carb bowls when floats have been accurately set

toytuff · « **Reply #36 on:** September 12, 2011, 10:28:06 am »

Appreciate the tip. Didn't work.

When the fuel is "on" with ignition "off" you can twist the throttle and see fuel coming out the front of the float bowl. (side facing air cleaner) It is not the fuel line.

If I remember correctly there is a small "o" ring that sits in number two (2) carburetor.

This would explain the "stumble" off idle. Accelerator pump is either dumping to much fuel or not enough. I would think the later.

tt

toytuff · « **Reply #37 on:** September 12, 2011, 11:00:52 am »

"UPDATE"

Well, things usually don't go easy for me. Today was different.

I backed off the float bowl screws. Two of them since you can't reach the other. I snugged them back up. Not super tight. Just snug.

No longer leaking fuel!

Still has a stumble off idle. Maybe a sync will do it.

Thanks for the replies.

tt

toytuff · « **Reply #38 on:** September 12, 2011, 11:44:16 am »

Quote from: toytuff on September 12, 2011, 11:00:52 am

"UPDATE"

Well, things usually don't go easy for me. Today was different.

I backed off the float bowl screws. Two of them since you can't reach the other. I snugged them back up. Not super tight. Just snug.

No longer leaking fuel! Still has a stumble off idle. Maybe a sync will do it.

Thanks for the replies.

tt

Spoke to soon. Leaking again. Guess I'll take them off again.

tt

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Author Topic: Carb's are finally done! (Read 3676 times)

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