A sad 750 sat unloved and needed a new home

I have owned easily over 150+ CB750s in the 25 years that I have been building them here in Southern California, I drag many home that have not seen the light of day for quite a few decades, and somehow, I manage to get them running and riding once more, thus saving one more machine from a sad life in the junk yard, of which always makes me smile to save a classic inline four machine.

I picked up this 750K model from a client that’s fallen on bad times and it had sat outside for a while, weather getting to it and as he was moving out of the area and this non running Honda needed a new home, so he called me and I picked her up and sat her inside to dry out as it had gotten wet from the rare rain storms we had here a few months ago.

So, I sat her in the barn, out of the elements and let her dry out, so on inspection I see the bike had been down, the stator case and transmission case was leaking oil, also I felt the carbs were sticking and refused to budge at all when I tried the throttle, so this needed some evaluation on my behalf to see what I have got myself into once more. I could see that the gearshift casing was a little warped, so I removed it and then looked in my old parts boxes and located an old Black version, this I cleaned up, sanded and gave it a Honda Silver coating, then fitted a OEM Honda Gasket and refitted.

I pulled the old gasket off and saw it was a Black aftermarket one, those are never any good anyway, so cleaned the gasket all off then used lacquer thinner to clean up the face edge and then fitted the replacement transmission cover and that looked and fitted much tighter and felt good.

This is not a show bike, I just wanted to get the old girl running again and later on will decide what I am going to do in the way of cleaning the bike up and will of course ride it for a minimum of 100 miles before I offer it up for sale.

The carb bank seemed ok until I pulled the last bowl off, oh dear, more calcium than cows’ teeth, this will take some work, but it will be sorted none the less, and have had many in this condition before, so it’s nothing that will phase me to give up.

So with the carbs off the bike, I could get to work on her, but many issues to address before I can get this machine to breathe life again, as the battery was dead, I purchased another 8 cell Lithium and charged it up, I needed to clean up some of the internal wire harness too.

 

The carbs are off and whilst they were off, I sprayed some Marvel Mystery oil into the back of the Bore as well as removing the spark plugs and poured some in the front, as I wanted to lube the bores with good stuff and not have the cylinders get scratched from being dry for so long, I have used marvel Mystery oil for decades, it’s great for engines and will creep down through the rings too and lubricate all the dry areas, giving me a good smooth bore for when i do fire the old girl up.

I cleaned up the points and fitted the new lithium battery, I then kicked the motor over to get all the lubrication going into the places it needs to be and I could hear that the motor was free and not seized, that’s always a good sign, but of course, if I get this to fire, there will be white and black smoke from the marvel mystery oil and whatever else was in there, and I know if it does do that, it will eventually clear out and be clear and run smoother. These engines are so bullet proof for their time and that’s why I love working on these models as well as 9 years of the same engine makes parts for available too.

As you can see from the damaged gauges, this poor old lady has had a tough time of it, but I will clean all this up later once I get some life back into her lungs once more, the top end needs cleaning up anyway and I like a clear area on the tripe tree.

 

The old plugs were not in the bike but i had a new set anyway, although I did not want to fit them yet as I wanted to kick the bike over numerous times to get all that Marvel mystery oil out of the bores, but it really needed doing and am glad that I gave the inline four some new Cough syrup.

I actually removed the old Coils as they looked to be dry rotted and spark is so important on these or any machine, so fitted a new set, just to make sure that I get enough zap to ignite the fuel when that time comes for it to have a go at firing up.

I shall be fitted the rebuilt carbs and right now I shall use the existing cables as I have no clue on the condition of the engine, and really do not want to fit many new parts and only find out the crank is bad etc., but she felt ok when I kicked her through to get the oil going.

The moment of truth is now upon us: