Topic: new to forum w/ 1977 CB750A "Hondamatic"

[avirnig]

As stated in the fuel injection conversion thread that another poster is working on for a CB750 SS, I plan on trying the EFI conversion, provided of course the other thread poster's conversion turns out well, and manages to hold up well, along with doing a cam swap, to get a little more "oomph" out of the 750 engine (the CBxxx"A" series bikes all were notoriously dog-ish performance-wise, compared to normally shifted bikes), and possibly also chain gear swaps to give it a bit lower RPMs at highway speeds (55-65 MPH)

Also, as stated in the other thread, This bike seems IDEAL for a resto-mod, such as what I plan to do with this bike. it has VERY little rust, and even the frame powdercoating seems quite good still (though i would have it re-done of course), along with the paint on the gas tank being lightly scratched. (no major dings supprisingly).

It is in the shop by the previous owner at the moment, which is actually where and how I found out about it, being worked on. The current owner brought it in with the intention of getting it running again, then selling it, AND, he only wants $750 bucks for it, or as he said, "a dollar a cc."

I will post pics in a couple months once I get a couple other things finished up that I am currently working on.

In the mean time, please feel free to comment on what you all think about my current plans, and if you have any suggestions to that end, or, if you have suggestions AGAINST one of my ideas for the bike, please give an explanation as to why you feel that way, so i can hear where you are coming from, instead of just a negative answer.

[Joel]

I'll definitely be watching the EFI stuff as it's something I'd be interested in doing in the future.  Looking forward to seeing some photos of the bike as well.  Welcome to the forums!

[avirnig]

I am hoping to have some pictures to put up here by tomorrow evening sometime. I am planning on going over to the shop where the bike is currently being serviced at over my lunch break, and take some photos so you all can get a good look at it. I will take a few over-alls, and mostly some close ups.

If you all have any suggestions on what exactly you want close ups of, please feel free to post here. I will try and get them to you ASAP.

[avirnig]

As promised, here are some pics of the bike as it sits now in the shop.









As you can see in the above photo, the side-cover on this side has had one tab on the top edge broken off, which will likely require me to find either a replacement hondamatic side cover (ideal, the other side cover is missing the hondamatic logo, and i could use the second hondamatic logo for the other side cover) or get another 750 side cover and just epoxy the missing piece in and have it repainted. I will have to see if I can FIND a hondamatic 750 sidecover with the badges intact before I decided what to do with this part. This part is only minor in the grand scheme of things, but its details like that that make or break a resto project.



















The seat cover appears to be original, and in EXTREMELY pristine condition, given the age of the bike. The tank, as you can see from the photos, has no dings or dents, only scratches in the paint, so the tank is also in excelent condition. the frame has VERY minor rust, mostly from rock chips from the front wheel. As stated previously, the metal undercarriage of the seat that hinges on its side is also in the same condition as the frame.... VERY minor rust, so that is also a bonus. As seen from the photos, the engine itself looks quite clean of grime, and no rust on anything.

I was contemplating today, while I was taking the photos, that i might have the little bits that were factory chromed, re-chromed, the frame re-powdercoated, the tank re-painted, and whatever else that was zink plated re-zinced.

what do you all think?

I have higher-rez versions available, if people want them, just PM me with which one you want.

As I said before, this bike seems IDEAL for a resto-mod project, such as what I have planned.

Please, any constructive comments would be greatly appreciated.

[avirnig]

well i finally have the bike and title in my posession (sp?).

i have decided to keep it stock and not go with the EFI conversion after all, and just do a complete restore to showroom condition if possible.

to do this, the frame will need to be stripped and repainted/powdercoated (not sure how the frame came from the factory) either that, or i will just paint it using a good undercoating material that is used on cars (usually black in color) and put a good chip-resistant clearcoat on top to minimize road rock chips.

as for the tank and side covers, i will be looking at getting a couple of side covers off ebay (they dont match the bike color, and have some cracks in them, but those are fairly easy fixes) and getting them and the tank repainted to match, preferably as close to the original color of the tank as i can get. the tank is the original tank, and has ZERO dings or dents, just minor scuffs and scratches in the paint itself, none of which are down to bare metal it looks like. i may want to replace the petcock though... we shall see.

as for the chrome, i am having a hard time finding NOS chrome fenders for this bike... do you think a stock CB750f/k/whatever one would bolt right up with no modifications?
the fenders right now *may* be able to be polished up to remove the pitting in the chrome, but i like to err on the side of caution and have a source for replacements to fall back on if it turns out they cannot be replaced.

the guages i would like to fix as well... have them re-faced and all... what would i be looking at for that?

as for the headlight, i am considering changing it over to a halogen h4 bulb mount using a completely different headlight bucket and bezel. or do you think i should leave it stock? the h4 i could get far longer than the stock bulbs im sure, and would probably produce a better beam of light as well.

i may take the entire wiring harness out and take a large sheet of plywood and lay the wires out  within a loom made of brads nailed part-way into the board, and then re-create the harness from scratch, including a new fuseblock using the spade type fuses instead of the round glass type ones that are most likely the stock style... those should be a little more vibration resistant than the glass ones. i can get wire from napa where i work in nearly any color i want, so i can probably recreate the harness using these wires that are similar in color to the originals to keep it as close to stock as possible. i will also be using some GM-type sealing connectors for where parts of the harness need to be disconnectable, such as for the neutral saftey switch, etc. obviously, these connectors will not be stock, BUT, they WILL be a much better connection than the old-style un-sealed molex connectors that were original on the stock bikes of that day.

for the engine, i will rebuild everything except the tranny, unless the tranny shows that it needs some work as well. i will try to source a good 4 into 2 exhaust for the bike, or even a 4 into 1 exhaust. it all depends on what i can find. obviously, it will be dificult to find NOS exhausts, but i will look for those first, since this is primarily a restoration as close to stock as i can get.

i have a lead on a 1976 goldwing, i believe it to be a GL1000, but it could be the LTD version too, i dont really know. that one will be my daily driver bike untill i get this one done, IF i actually buy the goldwing. after the hondamatic is finished, i may even restore the goldwing... again, IF i buy it. it all depends on the condition of the bike, and how willing the guy is to work with me on the price.

[XN]

Where in MN you live? I might not be using my rear fender from my 78 750k

[avirnig]

SE MN... a little town called hayfield. sort of right smack dab in the middle of the triangle created by austin, owatonna, and rochester.

[XN]

Yep I know where your at. I grew up in Austin.

Give me a little time here to see if my replacement is going to work and then I'll get back to ya. I'll have to check over my 78 fender, but what I remember it was in pretty good shape. 

[avirnig]

ok, thanks for looking over your fender. i just talked with the guy about the GL1000 goldwing, and it is in nearly as good of condition as the cb750a. it did sit for a good portion of last fall, so it may need the carbs re-tuned (goldwings of this era are notorious for needing to be re-tuned after a long layup) but other thank that, it seems like a solid bike. the resto on the CB750a will be taking a back seat until i get the goldwing fully road ready again. i will, however, be looking for parts for the hondamatic resto while this is going on as well.

[avirnig]

need some help. finally got the bike home to work on... needs some work to get running again.

bike starts and runs on its own (quite well actually.... idle stutters a bit, but once you give it a little throttle, it smooths back out) carbs will need to be adjusted.

front brake master cylinder is full of this gel-like gunk, presumably dried brake fluid. will need to clean this out, blow out the orifices, and also check the brake line and caliper for same gunk. fairly easy fix, just time consuming.

there are NO turn signals on the bike. someone must have taken them off the bike. will need to source some replacements, preferably, exact replacements.

horn doesnt work, not sure exacly why, might be wiring short, might be bad horn or switch... really dont know at this point.

my main concern though, at this point, is where the frick the engine number is located. again, this is a 1977 CB750A bike. i need the engine number to actually title and get tabs to ride the bike.

any help finding the engine number would be appreciated. thanks.

[BeSeeingYou]

It might be best to take apart the master cylinder and caliper.  I have just been through this with my 76 750F.  It would be tough to get all the junk and gelled fluid out otherwise.  A few of us have done this recently so there are a few threads about it.  Once apart you can put in fresh seals.  With the age of these bikes it's cheap insurance.

[avirnig]

what about the engine number location though? where is that located?

[avirnig]

ENGINE NUMBER FOUND!!!

only after looking at a 70-something photo in a service manual, presumably in french (which i dont speak a word of), i found the general vicinity of where the engine number was. it was hidden under the friggin air box. i had to get down on hands and knees just to see the damn thing.

but, now i have it and can get the bike titled again. it hasnt been titled since 1983. O.o starts and runs like a champ though, excepting the rough idle of course.

[avirnig]

ok. had a chance to dink around with the bike when the weather wasnt so bad.

the front brake squeals, so i will have to find some new OEM pads and probably a new rotor as well, since i do not believe you can resurface these safely, correct? otherwise, the brakes work quite well; i just have to get used to timing when i stop.

i had the engine running a while ago in february when we had a heat wave and it got up to like 60 degrees F. if i gave it a little throttle, it would bogg down, if i gave it more throttle, and the engine caught up, it would take off like a bat out of hell, rather suddenly i might add. ran the tank and carbs dry, then added one full can of seafoam and 2 gallons of gas. this seemed to help a bit. now today, i put brand new ngk D8EA plugs in, and ran it for a good while, including under load down the road, and now it runs quite well. i may only need to have the carbs synced on it to get it perfectly smooth.

the transmission seemed to have problems shifting from L to D (only 2 speeds on the tranny, remember), or more accurately, when you would shift from L to D. the tranny would want to kick back into L again, unless you held the shifter up for a second. once the bike warms up now, it seems to shift fine. this problem may have only been due to the cold weather, i dont know.

i still need turn signals, so for now, i have to get by using hand signals for turns and whatnot. the headlight and taillight work fine, including the brake light, however there is an ugly exposed wire under the seat near the front of the seat in the harness that seems to have overheated and melted the rubber or plastic insulation, so that will also need to be looked at.

this bike just needs a little TLC and she should run like new again.

[Sam Green Racing]

I'll try to remember to keep up with this thread as I am picking one up in November, hope you might throw some tips my way.

Sam.

[avirnig]

well, at the rate this one is going, i wont have alot of work to do on it, although when i do the actual restoration on it, down to the frame, i will probably rebuild the engine and carbs at that time just so it is all fresh. but for now, i will probably ride it most of this spring, at least until i get the gremlins exorcised out of the GL1000 goldwing i bought this spring. it may need a head gasket the way it is looking. i will know more once i do a compression test on it. the carbs will also deffinately need to be rebuilt and synced afterward.

[Hush]

Sam you bastid, where did you find one of these gems?
Bluddy Poms!
Avirnig, so pleased you decided to keep her stock, looks like such a nice bike, Spanner1 has a very nice example.
I've only ever seen one of these bikes in New Zealand and that was when I was a teenager in the 70's.
I love the unusual in most things, hence my old Police 650 restore.
Keep us up to date on your progress..........Hush.

[avirnig]

well, i have decided to try and bleed the front brakes to see if that stops the brake from dragging. i dunno if that will actually do the trick or not, but it beats having to take the caliper off, and apart to clean it and find out why it is sticking. if i DO have to take it apart, i really hope the piston is not pitted, otherwise i may have to go with a caliper from something like a CB750F and fab up a braket if it doesnt fit properly, if i cannot find a replacement piston for it.

hopefully, the calipers on bikes of that vintage are all the same.... it would certainly make our lives a bit easier.

[fuzzybutt]

nice looking 750a! i'm liking that exhaust too. a slight bend in the pipe to turn the mufflers up at about a 10-15 degree angle might look cool

[avirnig]

ok bled the brake. seemed to have helped slightly. i can roll the bike around now with my legs while sitting on it, though at speed, it still squeals so there is probably still a little bit of hang-up there. it looks like i will still have to rebuild the caliper. good news though, i did find someone on ebay, based out of st paul MN no less (i live in MN remember), who sells reproduction caliper pistons for these bikes. stainless steel no less, so it likely will not get pitted again for a looooong time. hoping i dont need a piston, but if i do, at least i know i can get a brand new repro one for less than a c-note.

i WOULD like to find a link or something to a pdf version of the shop manual, including the 750A supplement if possible. i have found several links to what seems to be the same shop manual, but it does not have the 750A supplement, which i would need to be able to work on the transmission. if anyone knows of where i can find a pdf of this supplement/manual OR the manual itself, please let me know here.

[ev0lve]

Not sure if these'll be helpful but maybe worth looking at?

http://www.hondamatic.net/HMC/tiki-directory_browse.php?parent=6

[avirnig]

that is perfect. i will print those parts out as soon as possible. that will help immensely when i go to rebuild that caliper.

is there any chance we could get that page added to some sort of sticky somewhere where we keep all the links to manuals?

[Sam Green Racing]

Not sure if these'll be helpful but maybe worth looking at?

http://www.hondamatic.net/HMC/tiki-directory_browse.php?parent=6

Thanks for that info Iggy.

Sam.

[avirnig]

well, im going to be changing the oil in the machine this afternoon (sat.). right now, i do not dare take the bike on a long distance cruise because of the brake still squealing, but i believe making an adjustment on the caliper adjustment bolt should fix this. bleeding the brakes fixed the brake hang-up i was having with it. i still will probably rebuild the caliper, however, i believe the '77 and '78s had an o-ring, besides the piston seal in the piston area on the caliper. if this is true, the o-ring i cannot find one of the exact dimensions, knowing honda liked to make thier o-rings odd sizes so you would HAVE to get them from a dealership. hopefully all i need is the seal for a rebuild.

i still need to sort out the turn signals; i do have a possible lead on a correct rear grab bar that goes around the back of the seat, which also SHOULD have the metal tube spacer-like thingies near the back of it for the rear turnsignal stem bolts, which i should also be able to get from the same place. i also need the front ones as well, and they said they should have some. once i get financially situated, i can see if they have those parts for sure. the grab bar will cost me about $175 + shipping, and the stem bolts/stems will be about $50 each + shipping, so not entirely too bad.

as a side note, does anyone know if bikes from this era had the horn wired through the turnsignal fuse, because my horn does not work, and my fusebox only APPEARS to have 2 fuses on this bike.

[avirnig]

ok. took the bike for its first longer(ish) ride. worked quite well actually, though i think i will have to get one of those cruise helper paddle thingies for the throttle grip, because my hand cramped up quickly from the strain of holding the throttle in position.

i took the windshield off the goldwing and put it on the hondamatic for this trip, so that i would not feel like i was going to be blown off the bike from the wind on my chest. worked better than i thought it would.

still needs to have the caliper and rotor looked at, squeals like a #$%* at lower speeds... higher speeds i cannot hear it over the engine revs, but i assume it is still there. the fork seal on the caliper side of the fork leaks pretty well as well, and sort of runs down the fork, so that could be the reason for the squeal too. either way, im going to rebuild the caliper at the very least with new pads, and possibly a new rotor as well, IF i can find a new replacement option still. we will see.

it still brakes and rides quite well, just sqeals to beat hell at the front end.

[avirnig]

well, decided to update my thread on this resto...

bike runs well, just needs the carbs balanced, and the engine itself is pretty much rideable as it is now, so shouldnt be too much work to balance them.

rebuilt the caliper, including a replacement piston (old one looked clean except for right where the caliper piston seal was, there was a ring of pits around the piston... not many pits total, but what few there were were really deep) brake no longer sqeals like a #$%*, and only squeals if i really have to crank on them to stop (I.E. emergency stops). as long as i use the back brake along with the front, i dont have to squeeze the front very hard and it doesnt sqeal. the sqealing may fade over time and usage, i dont know. NOT something im going to worry about terribly at this point.

as far as restoration parts, i have found on ebay, a set of headlight fork ears to replace what one of the PO's had done to eliminate the turn signals off the bike. also, bought another set of side covers, which will have to be repainted as they are not the correct color, but that is a minor fix anyway, since i will have the tank and side covers repainted anyway. all that is left really for parts to find, is the turn signals themselves, the rear grab bar (since it has the mounts for the rear turn signal stems) and the rear turn signal stems. i can have everything else that needs to be polished up, and if necessary, re-chromed/re-zinced as needed.

replaced the turn signal flasher, which makes the turn signals i jury-rigged from an old honda and kawa actually blink at the same pace... before, the right one blinked at a MUCH faster pace than the left. also, the horn/turn signal buzzer doesnt work at all. will need to fix that as well. not sure if it is the horn button for the horn that is not working, or what the deal is. ill narrow it down eventually. at least now it is in ridable condition.