Topic: Senior project for high school - 78 CB750K

[Restoration Fan]

So I rode Stella to the office yesterday.  It's about a 22 mile round trip.  Because I didn't want to ride her early in the morning while it's dark (too many crazy drivers in Atlanta rushing to get into the office before traffic starts), I waited until about 7 am to leave the house.  LOL, bad mistake...it turned a 20 minute drive into a 50 minute ride because of school buses and traffic. 

The point of that is that the trip TO the office, I rarely got the bike above 2500 rpm's.  The ride home however was glorious.  Sunny day with temperature in the mid-70's and low humidity. 

I charged my battery the night before and it was reading 13.1.  When I pulled back into my garage last night, it measured at 11.77.  Because of the morning stop & go traffic, I'm not sure whether this is due to a faulty regulator and/or rectifier or if the traffic was draining the battery.

Tonight, I plan to take the bike out and ride it with a lot of > 3500 riding for about 20 miles again and once again measure the voltage to see if the battery is getting re-charged.

We decided not to use a combination regulator/rectifier before because most people appear to mount theirs beneath the battery box.  Well, on a 78, there is a breather/air recirculator down there so there is no room to mount it easily. 

My question is this:  surely someone has a 77 or 78 with a breather and also uses the combination regulator/rectifier.  If so, how did you mount it?

I don't know for sure that mine is a problem yet but I'd like to know how to mount one in the event that I need to replace mine.

[SOHC4 Cafe Racer Fan]

Mine is mounted with the other electronics under the left side cover. It gets sufficient air flow.

[Restoration Fan]

Mine is mounted with the other electronics under the left side cover. It gets sufficient air flow.

So did you just drill a hole and screw it into the cover?  Or do you mean it's connected to the battery box there on the left side near the solenoid?

[Davez134]

Mine is mounted with the other electronics under the left side cover. It gets sufficient air flow.

I did the same. Mounted to the battery box to left of solenoid. I'll try and find a picture. Made a aluminum bracket to make it easier/clean. As stated, gets plenty of airflow. I'm sorry that I do not know if there is room here, as I have a 72, never seen a 77 or 78 electronics panel.

Edit: found pic.

[madmtnmotors]

I mounted mine (also a K8) to the bracket that used to hold the stock regulator. I bent the tabs to align with the new unit, but the next one I will probably use an aluminum plate to mount the reg/rect combo and drill holes in that plate to use the stock regulator mount. The aluminum plate will likely help cool the combo unit by serving as a heat sink too.

[SOHC4 Cafe Racer Fan]

It's mounted where the original was. 

[evanphi]

Mine is mounted where the original is, just with some alu brackets.

Made some brackets for my reg/rec... no more zip ties!

[Stev-o]

Ok, enough about mounting.

How 'bout keeping your R's above 5000! [that's where life begins!]

[Restoration Fan]

LOL, very true.  I just got back from a 10 mile ride and I stayed up there most of the time.  Inconclusive results on the voltage but it was at 12.8 when I left and it was at 12.75 when I got home.  I'm planning to ride it into the office again tomorrow and I'll see how it looks after the 20 mile ride.

Oh, and Wilbur, thank you very much for the call last night.  I took all 4 pipes off and put them back on, making sure they were on properly and torqued down properly.  Now she literally has that sewing machine sound and it makes a huge difference on the performance.

[madmtnmotors]

Happy to help. Making them run good is very rewarding indeed.

[Stev-o]

Ron - very simple task to check your charging system: start the bike and let it idle.
Check voltage. Then hold a fast idle at 3000 & 4000, voltage should rise if system is charging. I bet you knew this, though.

[Restoration Fan]

Stev-o,
Actually I did not know that so thank you.  I rode it to my office this morning and she performed wonderfully.

The only thing I'm still not sure about with her (besides the charging) is the clutch adjustment.  I've adjusted it about 4 or 5 times now, trying to get it just right.  Coming out of neutral down into first, it still makes a bit of a clunking noise as it goes into the gear.  It seems to shift smoothly into all other gears up and down the tree without clunking but that noise going into first just kind of makes me cringe.  Am I just worrying too much or should I keep adjusting until I get rid of that noise?

[calj737]

typically "clunking" into first gear is an indication of the trans not being synchronized due to engine speed. Try double clutching when downshifting into 1st and see if that helps.

[evanphi]

Stev-o,
Actually I did not know that so thank you.  I rode it to my office this morning and she performed wonderfully.

The only thing I'm still not sure about with her (besides the charging) is the clutch adjustment.  I've adjusted it about 4 or 5 times now, trying to get it just right.  Coming out of neutral down into first, it still makes a bit of a clunking noise as it goes into the gear.  It seems to shift smoothly into all other gears up and down the tree without clunking but that noise going into first just kind of makes me cringe.  Am I just worrying too much or should I keep adjusting until I get rid of that noise?

I find I get more of a clunk when the oil is cold and I've been revving to try and warm things up a touch before riding. All that revving throws the gear sync out a bit, as calj737 said.

[Restoration Fan]

typically "clunking" into first gear is an indication of the trans not being synchronized due to engine speed. Try double clutching when downshifting into 1st and see if that helps.

I'm talking about when I'm sitting still at a light and I put it into neutral.  When the light turns green, I shift into first to take off and makes a clunking sound.  It works fine downshifting into first as I'm approaching a red light.

[70CB750]

typically "clunking" into first gear is an indication of the trans not being synchronized due to engine speed. Try double clutching when downshifting into 1st and see if that helps.

I'm talking about when I'm sitting still at a light and I put it into neutral.  When the light turns green, I shift into first to take off and makes a clunking sound.  It works fine downshifting into first as I'm approaching a red light.

That's not an issue, that's a feature    Hondaman mentions it in his book somewhere, just the nature of these transmissions.

[calj737]

does the "clunk" happen when shifting into neutral, or after you've shifted and are taking off? Each is a symptom of a different problem.

If its the former, double-clutch because the trans is not in synch due to idle speed.
If its the latter, then you may have worn cush drive, chain lash issues, or trans problems.

And, a little wisdom thrown your way: Do NOT sit at a light with your bike in neutral! This is a major mistake because it prevents you from escaping quickly should a car behind you decide not to stop, or worse, decide to go when you are stopped. Its a bad practice by new riders to sit in neutral. Clutch in, in gear, eyes up! Always looking around at whats coming, Ron.

Sermon over 

[knottedknickers]

<snip> Clutch in, in gear, eyes up! Always looking around at whats coming, Ron.

Sermon over 

I appreciate safety sermons! A good reminder for new and old riders. I would only add: and watch your mirrors. [Probably included in "Always looking around at what's coming," but might as well mention it specifically.]

[calj737]

Who uses mirrors?? Cafe bikes don't have them! 

[evanphi]

Who uses mirrors?? Cafe bikes don't have them! 

I only have one!

and ++++++1 to your advice on staying in first. Left foot goes down, right foot stays on brake to keep the light on to increase visibility, then I can rest my Right hand. Left hand gets a break when I get moving again.

[knottedknickers]

Who uses mirrors?? Cafe bikes don't have them! 

Sorry... "Use the eyes in the back of your head!" [Q: Do cafe bike riders wear helmets?]

[Restoration Fan]

Who uses mirrors?? Cafe bikes don't have them! 

It's funny you should mention that, cal.  I was checking my mirrors this morning as I rode in because I was in a fair amount of traffic but we were all moving along a pace of 35 - 50 miles per hour.  At one point, I realized that I have to slightly turn my head to the side to get a good clear picture of what's going on behind me in my left mirror but my right one is really good.  That triggered the thought and I looked down at the handle bars past my arms: 

I'll bet that the view from bar-end mirrors is somewhat obstructed by your arms and you'll have to do like I do with my left mirror...slightly move your head to get a clear view for each side.

[70CB750]

My bar end mirrors are clearly visible with just eye movement - it all depends how you set them.

[calj737]

My bar end mirrors are clearly visible with just eye movement - it all depends how you set them.

+1 Using the stock perch and location I find is actually harder as it obstructs my views. I appreciate that Stella is a "restoration" but, for me (I don't do restorations) I use a perch location and non-stock mirror or a bar end. I have found that flatter and wider struts from the perch get the mirrors outside my body line and still offering a great view.

I rode an '87/'91 BMW K bike with fairing mounted mirrors. They were both great in terms of offering visibility as they were farther forward and the reversed angle was very good for me to see outside my lane and behind me with a little movement of my neck.

But I am more concerned with correcting you from sitting in neutral than I am about a mirror rant 

[oldhatt45]

Ron,

What calj737 said is probably one of the most important things for safety, especially in town during rush hour!

And Cafe Riders wear Scully Helmets, so they don't need rear view mirrors.     
http://www.skully.com/#smartest-helmet

Charlie