Author Topic: Senior project for high school - 78 CB750K (Read 172805 times)

Restoration Fan · « **Reply #125 on:** October 30, 2014, 05:45:39 PM »

Two questions:
1. To remove the stator, did all of you guys purchase the tool from Honda or do you have some other method?
2. Is there a secret to splitting the front part of the speedometer from the chrome rear part of it? The black paint portion of ours needs to be repainted and, while it could be done with a lot of careful taping, I would like to know how to take the thing apart.

madmtnmotors · « **Reply #126 on:** October 30, 2014, 07:20:15 PM »

Quote from: Restoration Fan on October 30, 2014, 05:45:39 PM

Is there a secret to splitting the front part of the speedometer from the chrome rear part of it?

Remove the two acorn nuts from the back of the chrome cup. Feed the wires through the back of the cup as you lift the speedo out. The chrome cup is just for looks.

Stoli · « **Reply #127 on:** October 30, 2014, 07:51:03 PM »

The tool to remove the rotor is really just a bolt so you don't need to shell out for the Honda tool. If you want to take the rotor off, then you will need the bolt/tool. On one bike I screwed the bolt in all the way and gave it a good wack with a hammer and the rotor fell right off. On another I had to use an impact wrench on the bolt to get the rotor off. The bottom line is that you really don't have to take it off if you don't want to. It does make the reassembly a little easier by reducing the weight of the crank shaft.

Regarding the gauges, read the last few posts of the first page of my a Project #1 thread.

Restoration Fan · « **Reply #128 on:** October 30, 2014, 08:00:37 PM »

Quote from: Stoli on October 30, 2014, 07:51:03 PM

The bottom line is that you really don't have to take it off if you don't want to. It does make the reassembly a little easier by reducing the weight of the crank shaft.

The manual says to remove the stator as well as the gear shift levers etc to the right of the stator before splitting open the top and bottom of the case. Is that not necessary?

grcamna2 · « **Reply #129 on:** October 30, 2014, 08:07:12 PM »

Quote from: Restoration Fan on October 30, 2014, 08:00:37 PM

Quote from: Stoli on October 30, 2014, 07:51:03 PM
The bottom line is that you really don't have to take it off if you don't want to. It does make the reassembly a little easier by reducing the weight of the crank shaft.

The manual says to remove the stator as well as the gear shift levers etc to the right of the stator before splitting open the top and bottom of the case. Is that not necessary?

if you didn't remove the stator or gearshift lever you couldn't replace the oil seals that need to be done for a rebuild.

Stoli · « **Reply #130 on:** October 31, 2014, 05:28:44 AM »

First of all, I could have my terminology wrong but I thought the "stator" coil is mounted to the inside of the cover. The "rotor" is mounted to the end of the crankshaft. The rotor, and rest of the alternator, sits in oil and there is no seal behind it. There is an oil seal on the other end of the crank by the points. You don't have to remove the rotor to change a seal or crack the case. It just makes reassembly a little easier but not much.

You do want to remove the gearshift mechanism. Still no oil seals that I am aware of but if memory serves, you wouldn't be able to remove the transmission unless you took off the gearshift mechanism. Take lots of pics while you do that. Will make reassembly easier.

What oil seals are you referring to grcamna?

Stoli · « **Reply #131 on:** October 31, 2014, 05:40:02 AM »

I know the manual says to remove the rotor but I can assure you that when I completed my first engine rebuild on a 750 K8, I never pulled the rotor off. Didn't buy the tool until rebuild 2 and that was because the rotor was a little rusty and I had one that I wanted to put in its place.

Restoration Fan · « **Reply #132 on:** October 31, 2014, 05:55:44 AM »

Guys, as always, I can't thank you enough for the advice and willingness to share your knowledge on this forum with a bunch of newbies like us.

We have a bunch of stuff going on this weekend with senior portraits and what not but Sunday we'll see if we can get the cases split open by removing just the shifting mechanisms and leaving the rotor on. (And Stoli, you were correct...I was saying stator but the stator coil is already off the engine. I meant the rotor.)

grcamna2 · « **Reply #133 on:** October 31, 2014, 06:00:31 AM »

Quote from: Stoli on October 31, 2014, 05:28:44 AM

First of all, I could have my terminology wrong but I thought the "stator" coil is mounted to the inside of the cover. The "rotor" is mounted to the end of the crankshaft. The rotor, and rest of the alternator, sits in oil and there is no seal behind it. There is an oil seal on the other end of the crank by the points. You don't have to remove the rotor to change a seal or crack the case. It just makes reassembly a little easier but not much.

You do want to remove the gearshift mechanism. Still no oil seals that I am aware of but if memory serves, you wouldn't be able to remove the transmission unless you took off the gearshift mechanism. Take lots of pics while you do that. Will make reassembly easier.

What oil seals are you referring to grcamna?

sorry,I was wrong;I was thinking of another bike.

Stoli · « **Reply #134 on:** October 31, 2014, 06:45:16 AM »

Cool. Maybe someone else will chime in between now and then and let us know their thoughts on this. I go by the book, like yourself, but this is one of those things that I found to be a big hassle and not really necessary. The removal bolt and an air impact wrench make quick work of it, but without both of those, you could be unnecessarily fighting with it for quite a while.

Stoli · « **Reply #135 on:** October 31, 2014, 06:53:42 AM »

As a reminder, be ready to drill out some or all of the screws that hold on the countershaft bearing holder. Those puppies are staked in there pretty tight and don't like to give up very easily, even with an impact driver there is a good chance you will strip the heads.

Restoration Fan · « **Reply #136 on:** October 31, 2014, 08:11:02 AM »

Quote from: Stoli on October 31, 2014, 06:53:42 AM

As a reminder, be ready to drill out some or all of the screws that hold on the countershaft bearing holder. Those puppies are staked in there pretty tight and don't like to give up very easily, even with an impact driver there is a good chance you will strip the heads.

Just out of curiosity, do you guys use regular metric Philips head screwdrivers or did you purchase some of the JIS screwdrivers? I'm asking because I've ordered some of the JIS ones and I'm waiting on them to arrive.

AintNoEasyWay · « **Reply #137 on:** October 31, 2014, 09:49:02 AM »

I have just one JIS screwdriver that has really saved me a lot of pain. I also have a JIS impact driver that has saved me from even more trouble.

calj737 · « **Reply #138 on:** October 31, 2014, 09:58:35 AM »

JIS work best. I usually drill out the old screws with a bit, then replace with either a Phillips or Socket head later. Simpler.

Stoli · « **Reply #139 on:** October 31, 2014, 10:26:02 AM »

Not sure what type of bit I have but it is decent quality (edges are still nice and sharp). Don't think it is a JIS bit though. The driver itself is a craftsman but I think the original bit that came with it broke at some point. Those screws are kind of soft so they strip pretty easy. The good thing is that they are easy to drill out because they are so soft.

Restoration Fan · « **Reply #140 on:** October 31, 2014, 05:50:52 PM »

Center stand is still tacky to touch so I left it drying in the garage but the top & bottom trees and the kickstand are ready. The kid is doing pretty decently with the rattle can.

Took the wheels to a local bike tire dealer today and they removed the tires for $5 per tire. I also purchased another gallon of Metal Rescue, but looking at the spokes more closely, I'm not sure the spokes are going to clean up enough to be passable, even if the Metal Rescue removes all the rust.

Got several items almost ready to be painted. The prep stage is what takes so long but you guys were 100% correct. It makes all the difference in the world in how the final product looks. How do you guys surface your front rotors? I checked and the minimum thickness spec is 6 mm and this one is over 7 mm, so I have plenty of thickness but I'd like to get rid of the rings on the surface of the rotor.

Finally, got my baby back from the mechanics today. Going to be sorry to see her go but I've dumped too much money into trying to get her back working properly and it's time to sell her and get me a truck. Gotta have something to bring home the next bike after this one is finished.

Restoration Fan · « **Reply #141 on:** October 31, 2014, 06:36:15 PM »

Also, I asked the guy at the tire shop what tire he recommended. I told him I'd mostly be riding the bike around town and on weekend rides up into the mountains. He recommended the Dunlop D404's. Anyone have experience with these tires and have opinion one way or the other?

calj737 · « **Reply #142 on:** October 31, 2014, 06:41:10 PM »

I'd replace the spokes with either stock units or stainless units from Buchanan's.

Love the Benz!

I am partial to the Avon RoadRider or Metzlers. Lots use Bridgestones, Dunlops and others Shinkos. You choose!

Stev-o · « **Reply #143 on:** October 31, 2014, 07:02:20 PM »

Quote from: calj737 on October 31, 2014, 06:41:10 PM

I'd replace the spokes with either stock units or stainless units from Buchanan's.

+1. I'd consider new rims too, if in the budget. I had Dunlop 404's on my K8, good tire. I prefer the BT45 that I have on my K4 though. Roadriders are great tires too.

Restoration Fan · « **Reply #144 on:** October 31, 2014, 07:14:07 PM »

Quote from: calj737 on October 31, 2014, 06:41:10 PM

I'd replace the spokes with either stock units or stainless units from Buchanan's.

Love the Benz!

I am partial to the Avon RoadRider or Metzlers. Lots use Bridgestones, Dunlops and others Shinkos. You choose!

Thanks, I love that car too. I blew the motor in it almost a year ago and had it rebuilt. Long story short but after dumping 5 grand into it, it's still not running right. If someone has the knowledge and time, they're going to get a steal on this car when I sell it.

Any idea where I can get the stainless steel for the 17" rear rim I have? I only see 16" and 18" on this site.

http://www.buchananspokes.com/products/spoke_kits_honda_cb.asp

knottedknickers · « **Reply #145 on:** October 31, 2014, 07:39:56 PM »

Quote from: Stoli on October 31, 2014, 05:28:44 AM

<snip>

You do want to remove the gearshift mechanism. Still no oil seals that I am aware of but if memory serves, you wouldn't be able to remove the transmission unless you took off the gearshift mechanism. Take lots of pics while you do that. Will make reassembly easier.

What oil seals are you referring to grcamna?

Could it be the seal in the counter shaft oiler? Seems it's pretty important to replace that one for smooth shifting. See here for details.

calj737 · « **Reply #146 on:** October 31, 2014, 08:48:13 PM »

You should have no problems calling them and asking for 17". It's a standard length spoke for them and on certain CBs. Worst case, you'd have to send the rear hub and rim to them, they make them and send back to you (laced and trued even if you desire, though that does add some cost).

Stoli · « **Reply #147 on:** October 31, 2014, 09:33:00 PM »

Since the 77 and 78 Ks had a different rim than the earlier models, Buchanan's categorizes them as custom instead of a pre-packaged kit. You can read about my experience with that in my first build thread. If you aren't in a rush, I'd call them, order the customs and hope for the best. If they don't fit, then you can send them back and have them adjusted. I'd say there is a 75% chance that they will fit the first time.

Make sure you inspect your rims. You want to be sure that there is sufficient metal left where the nipples seat. It looks OK in the pic but make sure the rust hasn't eaten too much away.

Restoration Fan · « **Reply #148 on:** November 01, 2014, 12:29:54 PM »

OK, so we've made up our minds that we're going to replace the spokes with stainless steel spokes from Buchanan's once we can get them on the phone on Monday. But Logan brought up an interesting question that I thought I'd raise to you guys:
We'll use metal rescue on the rims themselves to get rid of the rust on them. After doing that, since the rims are trued right now, if we remove one spoke at a time and replace it with a new spoke, then tighten that down before starting on another spoke, shouldn't that mean that the wheel will be pretty much trued at the end of the replacement? For insurance sake, we could always replace the spokes in pretty much a criss-cross pattern sort of like you do when you're torqueing something down.

Am I crazy or does this actually make sense?

calj737 · « **Reply #149 on:** November 01, 2014, 01:01:33 PM »

No. Relieving the pressure on a spoke at a time will knock your rim out of true. Release them all, and install them and true later.

Truing is pretty easy, and take a few pictures of their pattern for reference later. Mark the valve location at 6/12:00 for a visual guide. Tension equally, bit by bit upon install.

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Author Topic: Senior project for high school - 78 CB750K (Read 172805 times)