Topic: Terry's Taxi CaB 750A project.

[RAFster122s]

Terry, why not wear the wool undershirt and pants below your work wear to keep you warm while working on the bike? Time to order another set...or a heavier set...

[MauiK3]

Great idea, have to be careful with fins.
Interesting that they made the frame so you can pull the valve cover.

[Alan F.]

I remember a member from the Greenspun days that had a K engine in an A frame for just this advantage, back before frame kits set us all free.

[Terry in Australia]

Geez that would be an engineering triumph, apart from the benefits of being able to do a top end rebuild with the engine in the frame, and of course you'd have a clutch, but it'd be a huge job to work out where you'd hang the oil bag (CB750A's are wet sump engines) and re-arrange all your electrics etc to suit.

Speaking of electrics, as I only had a little time out in the patio workshop today after work, then physio, some necessary shopping etc, I decided to install the battery, tidy up the electrics a tad, and see if there was any life in the old beast. It's not quite ready to fire into life yet as I need to fill the engine with oil (no, I don't know why it's empty.......) but I replaced all the missing fuses and installed the new, huge Motobatt battery:

Terry's CB750A  26 Jul 2021 by Terry Prendergast, on Flickr

Terry's CB750A  26 Jul 2021 1 by Terry Prendergast, on Flickr

I couldn't help myself, I had to turn the ignition on and see if I had any lights. I did!

Terry's CB750A  26 Jul 2021 2 by Terry Prendergast, on Flickr

No lights on though, then I noticed this:

Terry's CB750A  26 Jul 2021 3 by Terry Prendergast, on Flickr

I guess I'll be pulling the headlight apart tomorrow to work out what has been disconnected. Oh well, it was getting dark, hmmnn, why not see if it had spark? I found an old spark plug and connected it up, hit the starter, and I had spark, woohoo! As far as I know this bike hasn't been started for at least 3 years, so as long as I haven't stuffed the carbs up, I should get the thing running this week.

Both tyres are cracked and rock hard, the back tyre was flat but I pumped it up, and if it's not raining I think I will have to test the auto transmission and do a careful "blocky". More tomorrow.

[Tintop]

an other interesting project Terry, subscribed.

[MauiK3]

By the gauges, there is an empty bracket, maybe for a choke pull?
It will be cool to see/hear it run.

[Terry in Australia]

Thanks guys, yep, I managed to snap the semi seized choke cable with one mighty pull yesterday Steve, but I’m pretty sure I have a new one somewhere. I might drop what oil there is in it out and install a new oil filter tonight along with some fresh oil before I fire it up for the first time in a long time, for some reason amongst the parts in the carton, Vik sent me a new oil filter and a used oil filter, along with a used air filter.

I opened the airbox and it was empty, but then I remembered that at one stage Vik had 2 Auto’s, so I presume the new air filter went into the other bike, as he never had this one running, and I’m betting that the new oil filter went into the other bike too. No biggie, I’m learning much more by exploring all the issues I’m finding with this thing, as I slowly bring it back to life.

[Terry in Australia]

Well it's an official red letter day today, the Taxi CaB750 is a runner! But I digress. First job was to drop the oil and filter canister. Less than a pint of black oil came out of that massive sump pan. Isn't it a pity you can't bolt one of these onto a "normal" CB750?

url=https://flic.kr/p/2mdBbPc][/url]Terry’s Taxi 27 July 2021 1 by Terry Prendergast, on Flickr

I unbolted the (loose) oil filter bolt, dropped the canister and it was empty, except for the spring. No biggie, I had a new filter and washer, so I shoved them in.

Terry’s Taxi 27 July 2021 by Terry Prendergast, on Flickr

I filled the bike up with oil, which is dead easy on an auto, no mucking around with oil tanks etc, just stick it straight into the engine.

Terry’s Taxi 27 July 2021 3 by Terry Prendergast, on Flickr

I stole 10 litres of fresh fuel out of my K2 and made up a concoction of fuel, 2 stroke oil, upper cylinder lubricant, and Seafoam, and dumped it in. I figured that seeing the engine has not been run in several years, it's gonna be pretty dry, so all those oily additives can't hurt. I ended up only tipping 5 litres into the tank, as that is around a quarter of a tankful, and any more would have made the tank too heavy to remove, which I will have to do again tomorrow when I install the choke cable and the airbox. Yes I know, 10 litres is only around 20 pounds, but hey, I'm old, and I don't want to do any damage to this old survivor.....

There were a couple of spare hoses hanging off the PD carbs. The old round top carbs have breather tubes that sit on top of the airbox, but I don't remember any breather hoses on F2 or K7 carbs? One was obviously a vacuum hose to go to some sort of vacuum operated switch that I couldn't see where it was connected, so ignored the switch as I knew I had spark and used a screw to block the hose. I should have blocked the other one as well, but I will tomorrow. 

Anyhoo, the engine had fresh oil and a new filter, the valve clearances have been done, the points and plugs have been cleaned, the carbs have been cleaned and rebuilt, the headers are back on, it's cold and windy, I'm wearing sunglasses and have half a pack of cigarettes, so I turned the key, and hit the button. OK, it didn't start right up, but it did fire, so I persevered and manually operated the choke, twisted the throttle a few times to get the accelerator pump working and hit the tit again, and Varoomba! Away it went!

OK, so it's a runner, I'm happy as a pig in poo, and life is good in the patio workshop. (3 bikes parked there, and all of them are runners) Tomorrow I'll do the afore mentioned finishing off, then think about the wiring in the headlight, the (missing) rear indicators and grabrail, (which will involve some redneck engineering...) the front brakes, and some new tyres. Hmmnn, the lockdown finishes at midnight, I think I might whip the wheels off and get some new rubber tomorrow. Why not?    

[ozpacman]

Well done Terry! Yes the 750A is certainly pretty thin on the ground here.

At least now when old mate wanders up to you at the servo and says, "I had a Honda Four just like that back in the day." You'll be able to say, "Ah, no you didn't mate!"

[PeWe]

Good news Terry!
It sounds really nice. As a mix between a fishing boat and an old US muscle car!

Bike is eager for a ride too with that spinning wheel!!

[MauiK3]

Awesome!
Doesn't sound too bad either. You'll be the talk of the tavern.

[seanbarney41]

so funny that everybody is all excited about riding this...the one I rode was definitely not ha ha

[Terry in Australia]

Thanks guys, I'm really stoked that it fired up so easily, considering that it's been sitting for so long, unloved. I'm waiting for the two stainless steel 15 degree bends to arrive so that I can install the new stainless megaphones that should look close to the OEM system, but with a nicer note than it has now.

Now that our lockdown is over I can whip the wheels off and take them over to the tyre shop and buy two new Stinko's for it, as well as getting that new Michelin tyre installed on the T350 front wheel. The weather is all over the shop today, was as black as a Welsh coal mine outside a few minutes ago and the rain was coming in sideways, but the sun has come out again so I might get some quality bike time in after I finish work.

Sean, being one of the biggest detractors of Auto's in the past as you know, I'm not expecting scary fast performance, but that's OK, this is a multi phase build. Firstly, I need to get it registered here in Oz for the first time. (Vik never had it running, so it's been sitting around since it was imported 3 or 4 years ago) To do that, I have to take it to an engineer to have it inspected to ensure that it complies with Oz regulations. I've been told by Trevor that the closer the thing is to stock, the more chance I have of getting it past this first hurdle. I then have to take it to a roadworthy inspector to get that piece of paper, then apply for a club permit so I can legally ride it.

Once it's legal and I've experienced it's awesome performance, I'll modify it for a bit more. Sammy Green tells me that the auto transmissions in these things are like powerglides, they can take a lot of punishment without any major mods. I'm not gonna go mental with it, because there's no point, I don't want to turn it into an unreliable pig, so a mild performance increase is the plan.

I have a complete F2 top end with a reconditioned head. I've also got some freshly bored 64mm (810cc) barrels, so I've bought some new CB350 pistons, which will give it a high compression ratio, probably around 12:1, or more due to the high domes.

I'll take another look at the head that may have had a bit of port work too. I've got a nice Andrews A grind cam which is a great all round "drop in" cam, so should work well with the high comp pistons. I'll take the really nice PD carbs off my F2 (which I'll sell once it gets warm again) and install them, along with heavy duty valve springs and hardware from CycleX. I've got a new Dyna S ignition and Magna (Dyna knockoff) coils and new Bosch leads, so with that big arse battery, it should have a nice fat spark, even with lights on all the time, unless I buy an Australian switch block so I can turn them off.

Anyway, with the abovementioned mods, it should be a fun ride, while still looking essentially stock. I quite like the upright seating position and I haven't heard any negative reports regarding their touring capabilities, so I'm hoping it'll be a fun bike to do 100+ mile rides on, we'll see.    

[seanbarney41]

I don't know.  I guess to me, it's not the lack of power and acceleration that makes these so boring.  Without the clutch and shifting the ride is just so utilitarian and drab.  What's the point?  Of course, the A's are a godsend to many physically disabled.  I am curious to see what you think and I always enjoy your threads.  Hell, at least its not a CX500 or a Sportster! lol

[Terry in Australia]

Ha ha, thanks mate, I honestly can't defend something I've never ridden but the guys I've known who own them reckon they're fantastic, to me it's just a nice clean bike that hasn't been messed with, unlike most of the sh1theaps that I've started with, and even though I paid Vik more than he bought it for, I reckon it was cheap, around half the price that I've seen two other Auto's go for.

As you probably know Brian (Bear) has also bought one which will be great for him as he's a paraplegic, so I'll have another member here to trade notes with. Whatever happens, I'll give an honest appraisal of what I think it's like, and whether or not I'll be keeping it long term.

[Terry in Australia]

Well it was a miserable day when I wandered outside to play with my Auto, but I was keen to get on with it. I didn't pull the wheels off yet, I'll do that on the weekend, I thought I'd install the choke cable and the airbox, but the bloody choke mechanism isn't working as it should. If you've had any experience with PD carbs, the choke setup isn't as simple as that on the old "Round Top" carbs, it's a weird spring loaded affair with no direct connection. I'm not sure why, but this is the first set that I've had that didn't work. Because the PD carbs are set up so lean, there's no way they'll start without a choke, and unlike the Mikuni HSR42 on my magnificent Harley Sportster, I can't just crank the throttle a couple of times and hit the button without any need for a stinking choke, even though the PD carbs have accelerator pumps. Go figure......

Anyway, not to be discouraged, I decided to make some temporary patches for the rotted out exhaust, and see if that would quieten it down some. It did.

[PeWe]

It can be an easy to ride city/shopping cruiser.

[Terry in Australia]

Yeah mate, it'll be interesting to actually take it for a ride and see what it's like.

[Kelly E]

I'm looking forward to seeing how well it goes after you go through the motor.

[PeWe]

It will no longer go, it will run!!

[MauiK3]

Maybe make an 836 out of it, a real sleeper!

[Don R]

 Be very aware of revving it up when you think it's in N but might not be. I recently got drug by an XR70R doing just that. It has no lights or any safety devices.

[Terry in Australia]

Ha ha, we've all done that Don, but I think the last time it happened to me was in the early 70's? The Auto has no tacho, instead it has a set of idiot lights (check the first video that I posted) that tell you if you're in "Neutral", "First" or "Second". (Drive)

Honda really put a lot of effort into building a motorcycle designed for stupid people. Apart from an auto transmission with lights to tell you what gear you're in, they marked the speedo to tell you what speed you should shift from first to second, but if you were really stupid, you could shift it into drive from a standstill and it'd shift up automatically, although the acceleration was affected.

On top of that, it has a parking brake so the bike won't roll backwards when parking on a hill, or maybe if doing a hill start, and if you're in gear and put it on the sidestand, it automatically shifts into neutral. It really is a mechanical marvel, if I can just get the choke working I can reinstall the airbox and be one step closer to getting this sucker finished before my Suzuki T500 arrives, and I start yet another build thread.

[grcamna2]

Terry,you've made good progress on that Automatic CB750A;do you think you'll use those stock mufflers after putting a permanent patch on the left pipe? Where did Vic ever get the idea of calling it Taxi ?  You don't plan on pulling a passenger trailer off the back,transport a few people around to different places ?? 

[dave the welder]

hey terry .i own the matic  sean is talking about. yes its slow but I think its fun .different  tho what I enjoy about it is stopping at a red light next to other bikes,leave it in high ,put my left hand somewhere   other then on handle bars.when light turns green twist throttle listen to them shift gears while you don't.next light they look at you asking what the heck is that??? its also great when cought in traffic jams your left hand will thank you