Topic: My First Project - '75 CB750F

[KHansen]

Over the weekend I picked up my first project bike. It was love at first sight even though it came mostly in boxes. Actually that is what attracted me to the bike in the first place. The bike ran last week and was taken apart by the previous owner (2nd owner overall) but he had to give it up because he bought a mustang and needed the garage spot. I bought it for $350 and the parts in question were the wiring harness, the chain, the tank, and the timing chain. It seemed like a manageable project for me and I drove from Columbus Ohio to Chicago to pick it up.

My mechanical abilities are about par but what I lack in knowledge I make up for with time. I have all the time in the world this summer (I am a college student forced to live at home one last summer) to bust my butt and make this bike a beauty. The tank is close to ruined by the original owner--he put a hole in the side and did a less than stellar job patching it. So if I have to buy a new tank I had planned on it.

I will post some pictures and a more detailed diagnosis tomorrow night. I bought the Clymer manual and have read it through twice. I have a garage with plenty of tools at my disposal and friends with limited friends in painting and mechanics.

I hope this thread documents my journey as well as a place to ask for advice on the steps I should take. I want to restore it first to its original glory and then modify it into a soft-core cafe racer. So I think step one is clean EVERYTHING. absolutely everything. I also want to get it bored and jetted and spend a special time with the engine and give it extra TLC.

I have a budget and would appreciate everyone's opinions on the cheaper--but still proper way--of doing everything.

Help me make this bike everything it should be.

[madmtnmotors]

You're on the right track by cleaning everything first. This includes the connectors in the wiring harnes. A bore cleaning brush for a .177 caliber works good for the female bullet connectors in the harness. I would do a compression check before teardown of the engine. If compression numbers are even in all four cylinders then I would put the bike back together and focus on everything else needed to make it a reliable daily driver, such as:

*Tires
*Chain/Sprockets
*Brakes
*ELectrical, which includes chasing the gremlins out that proliferate at corroded/loose connections
*If you take the engine out I would suggest valve seals along with the "coin" seals underneath the cam towers that seal the head stud pockets.
*New seals at the output shaft (front sprocket), shift shaft seal, kick shaft seal, tach cable drive seal
*Check forum member "Hondaman" posts for oil flow mod to the clutch hub and for o-ring replacement at the oil pump and transmission bearing.

I would leave the "Bore and build" of the engine for a future project. Funds are quickly exhausted when building an engine. If it ran good and compression numbers are even then I would continue to run the engine with the maintenance described above. I've got 60,000 relatively trouble-free miles on my stock engine and others have gone much further. I am currently working on my own project "Evolution" http://forums.sohc4.net/index.php?topic=100352.0 that will be a budget-concious build that will focus on reliability. These engines have plenty of power in stock trim so my project focus will be on the typically most neglected items (i.e. brakes, electrical, wheel bearings, oil seals, tires, suspension, and cosmetic) to make it a bike I would not hesitate to ride long haul. I'll splurge on the paint for the "tins" (tank and side covers) to top it off just because of the amount of effort required to do what I just desribed, and that doesn't even include tearing down the engine, which I consider to be a formidable undertaking in it's own right when done properly.

Good luck!

[KHansen]

So I worked for a couple hours today and made it a rolling chassis. Took the front fender off, the brakes, the handle bar, and all the miscellaneous wires. I also laid out all the pieces I have and plan on cleaning each and every one to see which are salvageable.

I have a family friend who works at Honda currently was a mechanic for these bikes back in his younger days. I will mulch his garden for his help with my engine. Step one is to check the compression but I don't have a tool that fits into the smaller spark plug holes. I will probably pass on boring the cylinders but I will change the rings and clean it from head to toe.

Tomorrow I will also soak the boots and other dried out pieces for 12 hours and make a plan of action for cleaning the chrome and the frame.

Can someone tell me the benefits of powder coating vs me cleaning it up and painting it myself?

Done with the boring bits here are some pictures.

[KHansen]

The spark plugs are a NGK D8EA. Now the Clymer manual says that for standard temperature and using the NGK it should be the D8ES... What problems do these pose?

[Jerry Rxman Griffin aka MuthaF'er]

Powder coating is usually done by someone else (1st benefit) and is MUCH more durable against mechanics tools, rocks, other scratches (2nd benefit) plus it looks great (3rd benefit).

[KHansen]

Powder coating is usually done by someone else (1st benefit) and is MUCH more durable against mechanics tools, rocks, other scratches (2nd benefit) plus it looks great (3rd benefit).

But what about price?

Also are there any members that are in the Columbus area?

[KHansen]

Over the past couple of days I have just done a lot of polishing and cleaning while looking for the next steps.

I have found an old family friend that is going to help me take apart and rebuild the engine all for the cost of mulching his yard. Sounds fair to me. So tonight the engine comes out and the frame is completely stripped. This weekend I will hopefully paint the frame and start taking stock of every piece I have and need.. The gas tank seems to be the biggest problem. Where does one go to get a tank that fits the mounts? I'm not opposed to custom or a different styling except for the price.

I wish I had more to post here but I have been struggling trying to make heads from tails on this project so far.

[KHansen]

I am currently rattle can painting a lot of pieces and will have pics up that up once it is done in the next week but the big news is I have finally gotten into the engine.

We started off by taking off the cover off. found that a little nut was off on the rocker arm and thankfully it hadn't fallen too far into the engine and didn't cause any problems at all. Took off the rocker arms and then slid the camshaft out while holding on to the timing chain.That let us get to the valves. Going one step further than that we saw there was a little carbon residue but that gets cleaned easily and its back to 100%. Going down the next step we got to the pistons and the cylinders. They looked like they weren't 37 years old but still had some ageing. There was some galling between the pistons and the cylinders but it's to be expected. Piston #3 was the worst out of all of them but still won't cause a problem. So the overall diagnosis is healthy just needs a checkup. We did a leakdown test of the valves and everything was perfect on the exhaust valves but on the intake valves #3 had a little bit of drool. not leaking, just the tiniest amount was getting through. So in the end I have to purchase a new top end gasket kit to put it back together. This includes all the rubber bits and what not that age no matter what with time. New piston circlips, these little #$%*s cost 10 cents each and each piston has 2 so a dollar max. A points and condenser tune up kit that takes care of the timing. I need to take it to a shop so the cylinders can get honed. It isn't necessary to bore the cylinders since there is no indication that they are losing their shape. A new intake valve for #3. Copper exhaust gaskets. and I need to synchronize the carbs when this is all done. Total cost: ~$250. But to have the most important part of the motorcycle in pristine condition? totally worth it.

In a week or so I should have a rolling frame with front forks and wheel cleaned up/painted and attached to a freshly painted frame. Where a clean engine will sit. The swing arm and the rear wheel also need to be cleaned this week to make this a viable goal. More pictures and posts to come.

[KHansen]

By far the nicest garage I have seen yet