Author Topic: Back at it again (Read 4878 times)

abliden71 · « **on:** June 04, 2015, 08:25:19 am »

Hello, and allow me to introduce myself. My name is Adam and I am rebuilding my 1973 750, again. I purchased this bike in 2010 (I think) for something like $400, with dreams of building a cool café bike. I got her home and within a few hours of tinkering I had her running. So, I started to rebuild her into the bike of my dream. I quickly learned a few very important things about building a "custom" motorcycle.
1) It takes knowledge.
2) Failure to plan is planning to fail.
3) This is the big one, DO NOT RIP APART A RUNNING MOTORCYCLE.
After the realization that I was in too deep I put the project into the shed and forgot about her. So here I am, a few years later and with a few more miles under my belt and hopefully a little wiser. I have decided to pull her out take her home and try again. I want to post my progress on the forum to try and keep myself motivated, informed, and hopefully with the guidance of some who know more than I avoid any major mistake. I also don't want to be "that guy" who only posts when in a jam.
So, without further adieu, PICTURES!

Step one, buy a shed to work in

Step two, drag the old lady out of the shed

I see potential

In her new home

madmtnmotors · « **Reply #1 on:** June 04, 2015, 08:41:54 am »

Good luck with the build. You at least have a leg up on many projects (including my current one) in that you have had a chance to actually drive yours for a spell and can make decisions based on how it performed. As long as the transmission is shifting good, and you don't plan to make a "racebike" out of it, then you should be able to avoid splitting the lower cases. If there are leaky gaskets, now would be the time to replace.

Clean it up as much or little as you like, get the wiring sorted, rebuild carbs and brakes, reassemble, enjoy.

70CB750 · « **Reply #2 on:** June 04, 2015, 08:44:35 am »

Following.

abliden71 · « **Reply #3 on:** June 04, 2015, 08:59:33 am »

I wish I could say I rode it. I think I sat on it and coasted down a hill into the shed. Last night I sprayed her down with purple power hit her with the hose and am currently sorting out the electrical demon that jammed me up last time. Right now that is my biggest objective.

70CB750 · « **Reply #4 on:** June 04, 2015, 09:16:00 am »

You may ended up with two bikes. Quite simple, really. You get this one on the road and start building second one to have a bike while this one is being rebuilt.

Happened to me

SOHC4 Cafe Racer Fan · « **Reply #5 on:** June 04, 2015, 09:19:32 am »

The fact that you got it to start and run is a major plus. If it was running without leaking, you are a huge leg up.

It does not appear that you did anything drastic (engine is still in the frame). You just have some covers off (clutch and points), the airbox and the tank. If wiring/electrical is the issue, that can be solved in many ways.

If the wiring appears in good condition and has not been messed with, you may be able to clean up the connectors, track down any shorts with a multimeter and fix it yourself. If the harness is pretty crusty (and cut into at places), you can also buy a reproduction harness for your model and clean up the other connectors. If you are more adventurous, you can re-wire the bike yourself and/or modernize it.

If electrical is the main issue, sort that out and then perform a major service on the bike. Go through it system by system -- electrical, carburetors, brakes, forks, etc. I would recommend replacing all of your bearings (in the steering head, wheels) and replace the swingarm bushings with new bronze ones.

Get the bike running reliably and RIDE it. Then, play with stylistic cosmetic changes incrementally.

70CB750 · « **Reply #6 on:** June 04, 2015, 09:24:58 am »

After you install new battery, connect it only for troubleshooting and riding. It may take a while to find all shorts in the system and they can either discharge the battery or start a fire.

abliden71 · « **Reply #7 on:** June 04, 2015, 09:25:44 am »

Thanks you guys for the feed back. I do have a rider. So this really is my project bike. More for fun then anything else. I have a feeling I know where my problem is. The RH switch came off a later model and has a R/Y, a Bk/R and 2 Bk wires. The harness is brand new, came with the bike so I am confident that it's not the issue. We shall see though.

abliden71 · « **Reply #8 on:** June 04, 2015, 09:29:56 am »

My other bae

abliden71 · « **Reply #9 on:** June 04, 2015, 07:42:13 pm »

Well after a bit of tinkering tonight. I have a few updates.
The problem was in my RH switch. (going to have to replace that with a proper one)
The electrical demon has been exercised
My brand new battery is dying ( I think (

But most importantly, she is turning over with a rigged up switch.

Please let me know if I have missed something. The starter sounds sluggish and cranking brings her down to 9v I hope a few hours on the trickle charger fixes that issue. Regardless, this was the main reason this project came to us screaming halt the first round and I am very proud that it's sorted out.
I hope to gather some feedback on what to do next. My thought is to reinstall the coils, wires, carbs and add fuel. If that goes well then (fingers crossed) she will run (be it poorly) and from there I'll put her back together.

70CB750 · « **Reply #10 on:** June 05, 2015, 04:27:38 am »

She sounds pretty normal, the slow crank is due to battery most likely. Did you clean grounds too? Like the connection from the battery to the frame/engine?

There is one more ground from the harness to the seat lock bolt - or coils bolt, it changed over the years.

abliden71 · « **Reply #11 on:** June 05, 2015, 06:15:41 am »

I know which one you are talking about. It's to the seat lock in this case. Like I said before, my biggest goal was to get that to happen, and with a brand new harness I haven't really looked at cleaning connections. I've noticed that the the bullet types look like they could be removed easily with a baby screwdriver or pick. I'm thinking if I can find them I'd like to replace them. A few have broken and I've used solderless terminals but the male ends are a hair bigger and widen the female bullets.

70CB750 · « **Reply #12 on:** June 05, 2015, 06:43:44 am »

Here is a source for connectors many of us use:

http://vintageconnections.com/

Seems like you are on the roll

abliden71 · « **Reply #13 on:** June 05, 2015, 06:49:20 am »

Thanks man, I'll check it out.
I am quite anxious to get my baby back together. I have the day off today and had hoped to get a few more odds and ends sorted out, but my Suzuki needs some tlc (valve shims, my favorite... -_-) today so that's in the agenda. Hopefully that won't take all day.

abliden71 · « **Reply #14 on:** June 06, 2015, 04:01:09 am »

Alright, some big steps have been taken forward. Yesterday I was able to put some more time into the starter button and with the help of my multi meter I was able to make the handlebar switch work, which a huge relief not to have to try and source another one. I got the coils back in place and the points cleaned up and working properly. I have a signal to the coils but no spark... I am thinking that most of these issues can all be traced to a weak battery. Again, have a signal to the coils but no spark, so I'm not terribly worried. I decided to get the carbs on and now have to rig up something temporary for fuel delivery. I have a few ideas but right now do not want to spend money on something that I can make with a bit of leftovers and a bit of wit. The battery I picked up has found a new home in the suki, because keeping a running bike running seems more important to me right now. So in the next few days I hope to get fuel into the carbs and hopefully, with aid from my jump box, get here to purr. Tonight I hope to free the seized caliper but not entirely sure how to go about that yet, (the Clymers is not at my house) I am hoping that if I can get her back on the bike and bypass the shotty rubber hose I can just push her through... I'll stare at her some later and see what comes to mind.

calj737 · « **Reply #15 on:** June 06, 2015, 04:43:48 am »

For your coils, if there is no spark, first verify that you have 12v present at the coils. Right handlebar switch, KILL is fed by BLACK wire from your harness. It then gets jumpered internal to feed BLK/WHT when in RUN. This BLK/WHT delivers power to the coils. Carefully inspect and trace its route and test along the way whether you have power at the coils.

If you have power there, move to the testing for resistance of the coils, plug caps, and do a bang up job of cleaning, setting the gap, and timing of your points. This type of problem is usually resolved by some elbow grease and not new parts. Of course, battery voltage is also critical

abliden71 · « **Reply #16 on:** June 06, 2015, 04:49:29 am »

The B/W had voltage, I suspect it is weak battery and the connections all could use some tlc. Battery box is charging so I'll play a little later today.

abliden71 · « **Reply #17 on:** June 08, 2015, 07:28:52 am »

So not alotnof work has-been done on the project today, my suzuki has had some issues that are more pressing. I have started to go through my parts basket and see what I have. I also decided to break the build into stages. Stage one will be safety and mechanical. Let's get her running right before spending money on things that just look nice, the old "chrome to don't get ya home" saying. Stage 2, cosmetics. They fun shiny bits. And stage 3 I have dubbed the dream stage. Things like big bore kits, front end swaps, and the likes of that.

One thing that I never realized was how much work goes into planning a one off bike. In my head I know what she will look like, but the devil is in the details. Things like what switches to use, what color do I paint her and what headlamp will look best, what the hell am I going to do with my almost nonexistent exhaust. The list goes on and on. But right now I have to put that out of my head and get on with the boring stuff.

If anyone has any advice on how to plan this kind of project, please let me know. Otherwise everyone can laugh as I butcher through this build. Lol

Sent from my SGP561 using Tapatalk

abliden71 · « **Reply #18 on:** June 09, 2015, 09:12:18 pm »

Today was a slow day, trying to get as much of this bike back together as I can just to get her started. Need to find the right bits to make a test fuel tank. If I can get her to run then I think I will jump over to cosmetic changes. I am getting tired of the ugly frame and dirty motor. I have seen a few people paint the engine without disassembly and I haven't seen anyone paint a frame with the engine in it. This will also allow a good time to change out frame bushing and bearings. So it looks like some careful tinkering followed by LOTS of cleaning.

Sent from my D6708 using Tapatalk

SOHC4 Cafe Racer Fan · « **Reply #19 on:** June 09, 2015, 09:40:41 pm »

Quote from: abliden71 on June 08, 2015, 07:28:52 am

So not alotnof work has-been done on the project today, my suzuki has had some issues that are more pressing. I have started to go through my parts basket and see what I have. I also decided to break the build into stages. Stage one will be safety and mechanical. Let's get her running right before spending money on things that just look nice, the old "chrome to don't get ya home" saying. Stage 2, cosmetics. They fun shiny bits. And stage 3 I have dubbed the dream stage. Things like big bore kits, front end swaps, and the likes of that.

One thing that I never realized was how much work goes into planning a one off bike. In my head I know what she will look like, but the devil is in the details. Things like what switches to use, what color do I paint her and what headlamp will look best, what the hell am I going to do with my almost nonexistent exhaust. The list goes on and on. But right now I have to put that out of my head and get on with the boring stuff.

If anyone has any advice on how to plan this kind of project, please let me know. Otherwise everyone can laugh as I butcher through this build. Lol

Sent from my SGP561 using Tapatalk

Good priorities.

From the video, it sounded more like the battery was anemic.

abliden71 · « **Reply #20 on:** June 10, 2015, 10:13:36 am »

Alright, I have made a big decision and I hope it's the right one. I am going to pull the engine (again). I have been staring at her all day thinking about it and reading about other peoples builds. So here is my logic. The frame and engine both need deep cleaning. All the mechanical issues I can think of can be addressed with no regard to the relation of frame and engine. As far as starting goes I know I have compression, and spark. I rebuildt the carbs the last go around but will do it again for the sake of doing it right. Things like bearings and bushings will be easier to handle without a few hundred pounds of engine. And as I mentioned before I'd like to paint everything. I want to do something extreme for the overall appearance but for the time being I think I am going to just cleaned her up a bit, detap and start looking at seat hoops and rattle can her. Once I chose a seat hoop and have it installed I can go for the all new frame paint. So let's get the show on the road.

Here she is moments before the engine comes out.

madmtnmotors · « **Reply #21 on:** June 10, 2015, 10:40:20 am »

A "furniture dolly" from Harbor Freight can be had for about $10 (small) to $15 (larger) which is basically just a wood frame with four casters. These make perfect engine carts for moving a motorcycle engine around. Makes it easy to roll under the bench or just roll it out of the way. Also protects the bottom from damage that might occur from dragging it around. I have at least two stored this way right now.

abliden71 · « **Reply #22 on:** June 10, 2015, 12:13:59 pm »

Coming along beautifully

A bit of back break later, here's the roller. Now to get the pressure washer

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SOHC4 Cafe Racer Fan · « **Reply #23 on:** June 10, 2015, 12:15:55 pm »

It looks like you are already underway on the shift linkage.

abliden71 · « **Reply #24 on:** June 10, 2015, 12:20:50 pm »

I actually just took the cover off because it was hanging up and getting all mared up. About the only thing I'm willing to do at this point is take a drive to the chiropractor. This bike isn't light and fighting it with front end and swing arm is a real b!tch. And believe me that engine didn't levitate onto the shelf on its own.

And a well earned treat

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Author Topic: Back at it again (Read 4878 times)