Author Topic: 1974 CB750K4 wrench and ride (Read 15170 times)

MCRider · « **Reply #50 on:** October 15, 2011, 02:03:04 PM »

Quote from: Brown Bomber on October 08, 2011, 04:19:09 AM

Neither the Honda Shop manual or the Clymer, specify which side faces out, but on the CMSL online parts fiche the illustration appears to show the solid side facing out, which is how I found my leaky one and how I put the new one in. No leaks since. Clymer does recommend using two long narrow screws to remove the old one, which you couldn't do with the open side facing out.

The rule of thumb is that the open side of any seal goes towards the oil. Never seen a case where this wasn't true.

thrutheframe · « **Reply #51 on:** October 15, 2011, 03:34:24 PM »

Quote from: MCRider on October 15, 2011, 02:03:04 PM

Quote from: Brown Bomber on October 08, 2011, 04:19:09 AM
Neither the Honda Shop manual or the Clymer, specify which side faces out, but on the CMSL online parts fiche the illustration appears to show the solid side facing out, which is how I found my leaky one and how I put the new one in. No leaks since. Clymer does recommend using two long narrow screws to remove the old one, which you couldn't do with the open side facing out.
The rule of thumb is that the open side of any seal goes towards the oil. Never seen a case where this wasn't true.

Sounds like a good rule of thumb and yes the other seals I can think of like a cam seal, a shifter seal, a clutch rod seal all face flat side out.

lucky · « **Reply #52 on:** October 15, 2011, 03:50:32 PM »

Quote from: Brown Bomber on October 08, 2011, 04:19:09 AM

Neither the Honda Shop manual or the Clymer, specify which side faces out, but on the CMSL online parts fiche the illustration appears to show the solid side facing out, which is how I found my leaky one and how I put the new one in. No leaks since. Clymer does recommend using two long narrow screws to remove the old one, which you couldn't do with the open side facing out.

The number side faces out , just like bearings. Solid side out.

bjatwood · « **Reply #53 on:** October 16, 2011, 07:29:19 AM »

I just replaced mine the same way I took the old one out. And according to the experts here, it was wrong. But either way PEOPLE it doesn't leak!

thrutheframe · « **Reply #54 on:** October 17, 2011, 02:10:34 PM »

Not alot to report on this bike. I've been hard on the 650 lately, I did however attach the fuel lines today. I plan to go back tonight and multi task a bit by draining my 750 oil tank and replacing the seal on the drain and cleaning up my 650 brake caliper.

thrutheframe · « **Reply #55 on:** October 17, 2011, 11:01:02 PM »

No oil tank project tonight. By the time I got back to my shop it was 11:15, I worked on the other bike and didn't even look at the 750.

thrutheframe · « **Reply #56 on:** October 18, 2011, 04:36:59 PM »

Two little but important things got accomplished tonite... my oil tank got drained and a copper crush washer installed. I switched it all out and refilled the oil tank with oil. I wiped all the oil off of everything and parked it on a fresh piece of floor to check for leaks tomorrow. As of now it hasn't leaked yet. The other good news is I was able to get my front brake bled. It took 8 repetitions of pumping it up and bleeding it plus a reservoir refill. I'm glad I have all my bikes in one place now. It makes it a lot easier.

thrutheframe · « **Reply #57 on:** October 18, 2011, 06:18:00 PM »

After I wrote the post above I was able to carry on and get my left side coil mounted, the hot wire connected to it and I made the two jumpers that go from the black wire to the coils. I held off on my right hand coil because I need to chase the threads out on the bracket and it was getting dark in that part of the warehouse. I dry fitted my carb to air box boots and discovered that I didn't order the screws for the clamps. Another trip to Small's PRO Hardware. I also don't know the proper orientation for the boots.
I bought some engine cleaner for my 650 and I'm also going to use it on this bike, luckily everything that needs cleaned up on this motor is behind the cylinders and easy to get to for the most part. The motor itself is clean of oil so I HOPE against HOPE that the motor is tight.

thrutheframe · « **Reply #58 on:** October 19, 2011, 06:20:03 PM »

My oil tank is leak free, you can see in the pic below the dry floor under the end of the pipes it was leaking about 5 good size drops a day.
I'm at the hardware store now and I plan to get the air box on the bike today, I probably won't get it started today but both of my SOHC4's are coming along nicely.

thrutheframe · « **Reply #59 on:** October 19, 2011, 06:41:00 PM »

I got alot done yesterday but not many good pics, the rain and blah in cincy isnt helping. I worked mainly on my 650 but I put about 2 hours into my 750 last night. I finished all the wiring to my coils and got the air box on. I hate that hazy "old plastic" look. I scrubbed the grime off but that was still there. It's on the surface but it wouldn't scrub off, it comes off with a finger nail but that would end up a huge mess. Can I soda blast it off or is there a plastic safe solvent that will remove it?. I'll try ot get a better pic today.

Brown Bomber · « **Reply #60 on:** October 20, 2011, 05:25:20 PM »

try WD-40 on that grime, it cuts old dried up oil and grease pretty good and won't hurt the plastic.

Stev-o · « **Reply #61 on:** October 21, 2011, 05:12:10 PM »

And then try Mothers Back to Black, it helps restore old plastic.

thrutheframe · « **Reply #62 on:** October 21, 2011, 05:53:09 PM »

I made a major blunder on this bike and don't know which came first the chicken or the egg. My main blunder was not checking the main fuse, PO had replaced the 15 amp fuse with a 30. I hooked everything up and put a freshly charged battery and cranked the bike over with no gas tank just to hear it crankover. I left the key on and started working on my right turn signal issue and in about 45 seconds I smelled smoke which was coming from just above the starter relay. I shut off the key and took a look around and saw that my main fuse was melted in the holder (not sure if it was already melted), the bullet connection coming off of the main battery lead to the rectifier was melted and my left coil had a smoke mark on it. The red and white leads off of the main battery lead were both fried and stiff so I had to pull the battery terminal off and replace the wire. While I was there I stripped the old, ratty insulation off and replaced it with 3 coats of shrink tubing and re-soldered the end in place. I replaced the main fuse circuit with a blade type and I replaced the 6 pin electrical connector. I'll eventually put a full blade type fuse box on this bike but the idea now is to make it run. I hooked it all back up with the coils out of the circuit and it holds, with the coils in the circuit it blows a 15 amp fuse. I have a set of stock 650 2 ohm coils that meter out so I'm going to put those on there to try to get it running.

I'm assuming the stains on the cases are dried gas. I hit this section with acetone real quick and it came right off.

Edit on January 20, 2013:

I found a nice gem that might have contributed to my electrical meltdown. I'm not sure if it was the cause but it certainly isn't a good thing.

I completely disassembled and rehabbed the entire switch.

thrutheframe · « **Reply #63 on:** October 24, 2011, 12:44:16 PM »

I had a pretty good morning working on my 750. I decided to put my dyna 2 ohm coils on this bike and put the stock coils back on my 650. I consoilidated the blue, yellow and black w/ white into a 4pin multi pin connector.

I static timed the bike using my multi meter, I got my test light out and the bulb was busted. I just hooked the meter to the tab that holds the static point contact and the arm on the other contact, get it close, then very slowly dial it in until it stops beeping right at the F. I was able to get it all timed out and the gaps to match at .013 in two passes. I'm waiting on spark plug cables and I can fire the bike up. I'm a tiny bit concermed about the motor... It felt normal at the kick start and it sounds fine when I turn it over with the starter but it sure turns easily with a wrench.

I bled the front brake last week and succeeded in getting it stuck which led to pulling the claliper. The pads were shot and its kinda crusty so I decided to rebuild it. I called Western Hills Honda and they had the pads and a bleeder valve, luckily the seal was reuseable. I'm amazed at how simple the caliper is on these old bikes.

I did NOT repaint the caliper, it was hard but I'm getting better at focusing wrench and ride versus a restoration. When the time comes to paint it, it's super easy to get off and apart.

thrutheframe · « **Reply #64 on:** October 24, 2011, 06:12:15 PM »

A few more shots from today.

thrutheframe · « **Reply #65 on:** October 26, 2011, 04:31:33 PM »

I got my plug wires and plugs today. The bike is ready to put a gas tank on and test start, not quite road ready but approaching the target.

thrutheframe · « **Reply #66 on:** October 26, 2011, 08:58:41 PM »

A lot of good and some bad today. I posted the spark shot from my shop earlier and went on to start the bike! Bad news, I can't get the front brake to bleed, I had it pumped up before but the pads were shot and it was stuck so I replaced the pads. Now it just pumps and pumps. I even vacuum pumped it helped ( I pumped 70ml of brake fluid through it) but still it doesn't feel tight and the pad doesn't budge. The only thing that has changed since it was bled and held is the caliper was removed and rebuilt. I reused the seal which was like new but a little dirty and I cleaned it up real nice. Plus it's not leaking fluid anywhere, could it leak air but not fluid?

Here are some shots from tonight....

thrutheframe · « **Reply #67 on:** October 26, 2011, 09:17:27 PM »

a little youtube iphone shego me-listen youtoo yah!!!

Scotty G'CB750

xXCafe500Xx · « **Reply #68 on:** October 26, 2011, 09:47:44 PM »

Man that's a beautiful sound! Even if she's running rough she still sounds great! Keep up the great work man

MCRider · « **Reply #69 on:** October 27, 2011, 04:57:28 AM »

re: the brakes. having just struggled thru mine, I can offer some sympathy and advice. I used the miteyvac as well. Couldn't get it to firm up. I had to take the caliper off and hold it up to make sure there wasn't a bubble trapped somewhere. it burped and bled up perfectly.

Bottom line, you've got an air bubble trapped soemwhere. IMO

thrutheframe · « **Reply #70 on:** October 27, 2011, 11:44:48 AM »

Quote from: MCRider on October 27, 2011, 04:57:28 AM

re: the brakes. having just struggled thru mine, I can offer some sympathy and advice. I used the miteyvac as well. Couldn't get it to firm up. I had to take the caliper off and hold it up to make sure there wasn't a bubble trapped somewhere. it burped and bled up perfectly.

Bottom line, you've got an air bubble trapped soemwhere. IMO

Indeed MC you were 100% correct. I turned the bars the other direction so the caliper was shifted, removed the reservoir lid, and tapped on the caliper and brake light switch both 100 times with a craftsman #2 Phillips. I hit it with the vacuum pump and instantly got fluid. Shes holding now and I'm going to attempt to clean up my exhaust flanges and the hardware associated with them. No glamor shots of brake bleeding sorry.

MCRider · « **Reply #71 on:** October 27, 2011, 12:35:12 PM »

Cool beans!

Stev-o · « **Reply #72 on:** October 27, 2011, 05:49:25 PM »

good news!

thrutheframe · « **Reply #73 on:** October 27, 2011, 06:12:38 PM »

Quote from: Stev-o on October 27, 2011, 05:49:25 PM

good news!

Thanks Stev-o. Seems this thing is like a roller coaster. Now the issues is two fold: 1. no exhaust gaskets, at least in cylinders 1 & 2, that's as far as I got

2. cylinder #2 has one flange screw broken off and one that is seized. the broken one, I pulled a blunder and drilled into it with a 3/16 but somehow I chose the wrong bit, too large for the larger ez out that I have. I guess I can get a larger one.... set backs

thrutheframe · « **Reply #74 on:** October 31, 2011, 07:09:38 PM »

I've decided that the head has to come off of this bike to fix the exhaust. This bike will probably sit or get some further chassis work over the next few months. Oncce winter kicks in I'll pull the head, check everytjing out and go from there.

News:

Author Topic: 1974 CB750K4 wrench and ride (Read 15170 times)