Author Topic: New CB750A Owner, A Few Questions Too... (Read 8474 times)

77Pinto · « **on:** April 29, 2012, 06:01:11 PM »

I just got my first Hondamatic, a 1978 CB750A. I am NOT new to bikes, or Hondas, as I have owned well over 100 over the years (3 or 4 SOHC 750s, 10 or so DOHCs, and one 350-four), and I have worked on a friend's 77 750A about 15 years ago as that one was 'stored' for over 10 years at that point; kool bike to ride around town. My love has been GLs for the last 25 years, and currently have a 1500, but this 750A was calling me. My 'new' Hondamatic had two owners before me (the last bought it in 1980), has 12080 on the clock, but according to the 80+ year old seller, it had not been running in about 20 years but the tire date codes indicate late 90s. As you can see from the photo, it was DIRTY. The layer of dust was thick, and you can see where I wiped the dust off the speedo to see the mileage. I took my time to get it back going (oil in the cylinders, let it sit for days and did it again, kicked it, repeated a few times, fresh oil and filter,...). I did the carb.s before I got my gasket kits, and the bike now runs FANTASTIC (and was able to ride it around my yard today), but I will pull them back off to install the new parts. The bike has a LIKE new Vetter as well as Shoei bags and a K/G trunk. All that stuff is coming off, and will be listed for sale here soon. Yes, the bike came with everything (at least the big parts) that was removed to install the add-ons. Still have a few things to do (tires, front brakes, carb. sync., cam chain adjust, and few other things), but its return from the dead is getting there.

I have a few questions related to the A, used the search but did not find what I was looking for.

First, the slow jets. They are round with no slots for a screw driver, and my Clymer says to take them out, but not HOW to do it. I know these books can be WRONG, as I found 20 years abo that there was wrong info on doing the timing belt adjustments on Wings, and what air jets go where in the GL1100s.

Second, the short vacuum hose that clamped to the top of the air box. It does not seem to have ever been connected on the side near the battery. Does it go anywhere?

Third, front master. Anyone have info on where to get a good kit to rebuild it? I was able to bring mine back to life, but it might be a good idea to install the new parts.

Fourth, battery. The CORRECT one was more than twice the price than one for a K/F of the same year, and it will 'fit', so I got one of those (an attempt to keep my cost down until I knew if it would run). Anyone have any issues doing this?

Fifth, gas tank. I need a good used one in burgandy. Mine is usable to hold gas, but I would like to get one that looks better.

I know I should ask all this in different threads....

Thanks in advance,
Bill

raymond10078 · « **Reply #1 on:** April 29, 2012, 07:34:56 PM »

1. The slow jet just pull out. Experience so far is that they'll press back in - and will stay there.

2. The vacuum hose - I recall that the solenoid (for the idle speed adjust) system vents to the air box. Check the Service Manual from this site - I recall that it is clearly shown there.

3. Master cylinder kits are available - just pricey. Use the Honda part number, and do a google search (45530-404-315).

4. Battery shouldn't be a problem - you just won't have as much amp-hour capacity to cope with a harder to start bike. In other words, it won't crank as long without going weak. If the bike is maintained well, and the battery put on a battery tender in the off season, you'll probably be OK.

5. Ebay.

77Pinto · « **Reply #2 on:** April 30, 2012, 04:50:49 AM »

Thanks for the info.

1) I gave one of the jets a tug but it did not force it until I had more info. The carb.s were nasty.... In all the bikes I have worked on I have never seen bowls that were BLACK, and I have never had to beat the heck out of the pins to get them out like this set. Even after soaking for days, I have no idea how I did not snap off a post or two.

2) You say that hose just hangs free, I trust that, as it looks like thats all it did.

3) I will check that out, thanks.

4) I figured that about the battery, but I just wanted to be sure my way of thinking was correct.

5) I did NOT want to hear that word. As many, I have a love/hate thing there. As mentioned, not in a rush on that anyway.

Two days after I found out about the soon to be 'my' 750A, my buddy that had the 77 called me and asked if I would re-restore his. Long story short: even that years ago he told me that if he ever sold it he would ask me first, he sold it to a friend of both of us; I was not too upset. That bike will be at my place on Friday for carb. and brake work. Not that I really WANT to, and I really don't have the time, but I have known these guys for better than 20 years.

ADDED: You say you want an early Wing. I know them inside-out. Get a 75-77, those are in my opinion the best, as they are sporty and easy to work on. If you get one and have questions, let me know.

Thanks again,
Bill

raymond10078 · « **Reply #3 on:** April 30, 2012, 05:42:10 AM »

Back to number 2: The vented line from the idle speed solenoid goes to the air box. Maybe we are talking about a different line. See page 2-12 of the Service Manual.

There are three hoses that connect to the air box.
1. is about 1/2" and connects to the oil/vapor separator.
2. is about 5/16 - 3/8" and is a drain line (referenced from the Owner's Manual). This is routed down, grouped with the other carb drain lines and battery vent line.
3. is about 5/16 - 3/8" as is from the solenoid referenced above.

77Pinto · « **Reply #4 on:** April 30, 2012, 09:38:29 AM »

I have the one that comes out of the front of the air cleaner box between 1 + 2, and connects to the line under the carb.s.

Below is a photo of the back end of the hose that is clamped to the top of the air cleaner box. It does not appear to ever have been connected to anything. The front of that same short section of vacuum line connects to the selinoid on the carb.s.

Bill

77Pinto · « **Reply #5 on:** May 02, 2012, 09:43:40 AM »

It dropped the accel pump, then a cylinder. It was exactly what I had expected based on how bad these carb.s were to start with, and the fact that I did not seperate them. Part of the 'problem' is that I was running a HEAVY dose of Seafoam, and figured it would loosen up some junk. Yep, had a little debris in all the bowls and accel pump. Cleaned it all out, but could not find a problem with number three, the one it dropped. Put it back together and still running on 1,2, and 4. I swapped plug wires from 2 to 3, no change; swapped plugs between 2 and 3, then number 2 did not fire. New plugs and presto!! Running even better than before!

Bill

salukispeed · « **Reply #6 on:** May 03, 2012, 09:41:40 AM »

Sounds like a good project and nice bike. I just rebuilt my 77 master and caliper last night with Mother honda parts, Very good quality Both available but a little pricy. The master kit was $38 and caliper O Ring was $12 but the old gritty and slimy garbage inside needed to be removed as the front was sticking just enough to squeek terribly. The caliper was much worse than the Master.

Master kit 40530-404-315
master diaphram 45520-300-000 ( mine was floppy and did not seal well )
caliper seal ring 45215-533-004

77Pinto · « **Reply #7 on:** May 03, 2012, 06:19:53 PM »

Thanks for the info.

On a side note: My buddy dropped off his 77a today. Too much stuff, not enough time.....

(I did notice that it does not have the vacuum line on the top of the air box like my 78)

Bill

77Pinto · « **Reply #8 on:** May 04, 2012, 07:54:54 PM »

I now have two awesome running 750As here, now I NEED Mac to come and get his out of my way. It did not need much, just carb. rebuild and adjust, valve adjustments, cam chain adjustment, front brake rebuild, plugs, points, oil & filter, battery install, and few other things.....

Bill

77Pinto · « **Reply #9 on:** May 05, 2012, 09:51:57 AM »

Mac just left with his bike in tow. The place that he sent his tank to for sealing did not send him the sender assy., the gas cap, or the door. Also, they left the filter tube in the tank!! He was happy the bike runs, but not with the other place.

Bill

chickenman_26 · « **Reply #10 on:** May 08, 2012, 04:42:56 PM »

Quote from: 77Pinto on May 05, 2012, 09:51:57 AM

Also, they left the filter tube in the tank!!

And applied sealer with it in there? Real rocket scientists, eh? Good luck getting that thing out.

Stu

77Pinto · « **Reply #11 on:** May 08, 2012, 08:36:30 PM »

It was not too bad to get out. I did my best to remove it out the bottom, but most came out the top.

Bill

77Pinto · « **Reply #12 on:** May 13, 2012, 06:32:23 PM »

Had the chance to tinker with the bike this weekend.

The vacuum line I was asking about is not for vacuum, its the bowl vent. I noticed this when working on Mac's 77.

I also noticed that my tank was painted Teal before it was painted burgandy, but not other evidence of a repaint. IF this was done anywhere else but the factory they did a geat job as its a PERFECT match to the side covers and those look untouched.

The saddle bags are off, the trunk and fairing are next.

Bill

77Pinto · « **Reply #13 on:** May 18, 2012, 09:47:52 AM »

Bags are all off, fairing as well. All the stock stuff is back on. The wires for the rear blinker lights were cut, but that was an easy fix.

A good looking (fixable) gas tank is the only thing I need to find.

Still running great, I might keep it, don't know yet.

Bill

77Pinto · « **Reply #14 on:** May 20, 2012, 02:59:30 PM »

FINALLY had the chance to tinker again.

Here is a updated photo, and yes, its the same bike.

Bill

raymond10078 · « **Reply #15 on:** May 20, 2012, 07:25:56 PM »

Looking sweet!

Mine is a basket case/barn find that is waiting on some attention - haven't ridden it at all this season . . . .

77Pinto · « **Reply #16 on:** May 20, 2012, 07:30:23 PM »

Thanks.

This was a barn find, kind of...

I don't get to spend much time working on it, but I have done lots anyway. Rode it around the yard more today than I had before. Would love to register it and keep it, but too many other projects are here too. Might put it up for sale soon, just don't know; I like it....

Bill

77Pinto · « **Reply #17 on:** May 29, 2012, 05:27:10 PM »

I added a K/G crash bar after this was taken.

Still need a better tank. This one holds gas, but had brake fluid drip on the right side, and its a shame because is NICE other than that.

77Pinto · « **Reply #18 on:** June 14, 2012, 08:24:44 AM »

Racked up over 7 miles and I have not even left my driveway!!

Maybe I will register this stupid thing....

Bill

77Pinto · « **Reply #19 on:** June 14, 2012, 02:39:40 PM »

Just purchased two more things for it: Insurance and a plate.

Just doubled the miles I put on it.

Now, who to will it to.... As soon as my wife finds out I'm dead....

ADDED: My idle bump-up thing stopped working. Carb.s to come off again, but need to find a thread or two about working on it first.

Bill

77Pinto · « **Reply #20 on:** June 18, 2012, 09:33:48 AM »

Got it done (again). Back to good working order. I am now to the point that I will venture futher from home with it. So far it has only been about a mile, and staying uphill so I could coast it home if I needed; never did.

A big thank you to this site for some of the details that I could not find eslewhere.

Bill

ADDED: The vacuum check valve stopped working. I installed one from a car I gutted and its back working again.

77Pinto · « **Reply #21 on:** June 19, 2012, 08:49:31 AM »

Road around today for a couple of hours. Have not had FUN just riding like this in a LONG time.

Bill

raymond10078 · « **Reply #22 on:** June 19, 2012, 10:29:41 AM »

My bike has been sitting for almost nine months - I've been building up parts for various rebuilds . . . .

Then, two weeks ago, my wife tells me that she misses riding. Well, I put the battery back in and brought it back to life.

We went riding this past Saturday - glad my wife spoke up - or I'd still be collecting parts - and waiting . . . .

They are no fun if you can't ride 'em!

P.S. I was thinking bikes, but I realize that it applies to the wife, too.

77Pinto · « **Reply #23 on:** June 20, 2012, 09:09:03 AM »

Note to self: Find out why the bike won't start when HOT. Ran around today in town, hot day, did not want to re-fire; just sputter. It seemed to be getting too much fuel so I pulled the air filter out and that let it start. The filter is not that dirty, but a new one is in the works.

Bill

salukispeed · « **Reply #24 on:** June 20, 2012, 09:19:24 AM »

Are you in the habbit of shutting off the fuel every time you stop. The old systems can flood when left with the gas on but so can any gravity system.

News:

Author Topic: New CB750A Owner, A Few Questions Too... (Read 8474 times)