Author Topic: K1 Hot Rod the Rat Race, new/old stuff.  (Read 25803 times)

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Online Don R

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Re: K1 Hot Rod going back together.
« Reply #175 on: March 09, 2023, 08:59:05 PM »
    Thanks Per,  I'm already scanning your info. L0L!  If the numbers stamped on the cam are degrees they must be at .020 lift or some crazy number like that. I'll leave this here for my future reference. I'm sure I have adjustable cam gears somewhere, but they must be in hiding tonight.
  One gear has a single hole slotted. I have no idea why.

 
http://forums.sohc4.net/index.php/topic,154588.0.html
« Last Edit: March 09, 2023, 09:06:57 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
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Offline PeWe

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Re: K1 Hot Rod going back together.
« Reply #176 on: March 09, 2023, 09:11:57 PM »
Ok, all those threads are useful. ;)
There lots of good info.
RC315 cam changed a little during the years if I remember correctly.
I tried different lash.
Cam need that huge lash of 0.012" (0.3mm).

My butt told me that more lash made better throttle response than 0.10/0.15mm lash. The smaller give higher, duration and overlap. Overlap reduce cylinder pressure and power. At least for me.
Higher compression needed.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Online Don R

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Re: K1 Hot Rod going back together.
« Reply #177 on: March 09, 2023, 09:23:22 PM »
 My Kenny Harmon F cam is at .008" lash if I recall correctly. I can hear the valvetrain noise over the 4-4 no number pipes.
 It is too much cam for the motor it is in, rarely if ever gets into its power band. I'm saving an F2 cam for when it's apart again. Or the other RC315.
  The recently declared scrap stroker motor has a good head with an Engle J cam.  410" if I remember right. I'm buying steel rods and a 12.5/1  970 kit for it. I have a 10,000 mile 10 oil change crank that will be  balanced.   
« Last Edit: March 09, 2023, 09:32:38 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
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 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: K1 Hot Rod going back together.
« Reply #178 on: March 10, 2023, 12:22:49 PM »
 One turns in the cam towers with a tiny bit of clearancing, one does not. It's on the same lobe of both cams. I may have to get the dial indicator out. One cam may be the early version of the 315 grind.
No matter how many times you paint over a shadow, it's still there.
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Offline newday777

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Re: K1 Hot Rod going back together.
« Reply #179 on: March 10, 2023, 01:40:54 PM »
Here are pictures of the RC315 I bought at a swap meet a year ago.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline grcamna2

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Re: K1 Hot Rod going back together.
« Reply #180 on: March 10, 2023, 02:07:47 PM »
I like that RC cam Stu;it looks real good.
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline newday777

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Re: K1 Hot Rod going back together.
« Reply #181 on: March 10, 2023, 05:00:51 PM »
I like that RC cam Stu;it looks real good.

At the price I paid I couldn't pass it up, he even included a stock cam with R9 on it if I remember correctly.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Online Don R

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Re: K1 Hot Rod going back together.
« Reply #182 on: March 11, 2023, 09:38:58 AM »
 There is a pic of a cam floating around here that says made in usa on it.

 The head is on and torqued a few rounds, it will be interesting to see the power difference between the 836 that  I built and this one that was supposedly assembled by a pro (the first time).  Anyway, it has new rings and a fresh head now. I'll go back out later, I stopped the torque at 15 ft. lbs.  I'll burnish the nuts and studs a time or two, neither are new, only new to each other. 
 
« Last Edit: March 11, 2023, 04:00:39 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline BenelliSEI

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Re: K1 Hot Rod going back together.
« Reply #183 on: March 11, 2023, 04:52:35 PM »
Don.... Random though just popped into my head. Completely unrelated to anything here. When you’ve installed a “9 hole clutch cover” did you trim a standard gasket to fit? Or have to find the correct gasket? Thanks!


Offline BenelliSEI

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Re: K1 Hot Rod going back together.
« Reply #185 on: March 12, 2023, 04:58:42 AM »
Thanks! John D.

Offline newday777

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Re: K1 Hot Rod going back together.
« Reply #186 on: March 12, 2023, 05:02:12 AM »
I have a couple of the 9 hole clutch cover gaskets from Honda.  I looked in my pictures but couldn't find them......
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline BenelliSEI

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Re: K1 Hot Rod going back together.
« Reply #187 on: March 12, 2023, 10:34:59 AM »
I have a couple of the 9 hole clutch cover gaskets from Honda.  I looked in my pictures but couldn't find them......

Stu….. want to sell them? John D.

Offline newday777

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Re: K1 Hot Rod going back together.
« Reply #188 on: March 12, 2023, 11:25:56 AM »
I have a couple of the 9 hole clutch cover gaskets from Honda.  I looked in my pictures but couldn't find them......

Stu….. want to sell them? John D.
Replied to your pm
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Online Don R

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Re: K1 Hot Rod going back together.
« Reply #189 on: March 12, 2023, 04:20:21 PM »
 I torqued the head last night, loosened, oiled the bolts and re-torqued today, got the cam towers in and put the cam gear back on the way it was. New O rings under the cam holders, I'm undecided if I'm going to check cam timing or run it like it was before, except with all of the parts installed. 
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: K1 Hot Rod going back together.
« Reply #190 on: March 14, 2023, 05:47:59 PM »
 The motor is buttoned up, the frame kit is re-installed. Carbs on, but not the header yet.
  I got the stretched stock swingarm mounted, it already had some snug needle bearings in it. Since this thing will be a low mileage unit I left it alone. The new grease zerks in the swingarm bolt worked like a dream. I moved the ground lug to the space between the frame and engine. Made a new chain, 108 links, 110 was too long, that some room for adjustment for when the sprockets and chain break in. I left the shorty shocks on it, that leaves the tire a bit towards the rear of the bobbed fender, I have another bobbed fender that needs body work and paint but was a bobbed late model fender for the long frame. It should work better there. 
 I straightened up the wiring a little more, found a loose motor mount bolt, tightened it up. That should have been already found during a nut and bolt check.   
 
 
« Last Edit: May 14, 2023, 09:41:05 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: K1 Hot Rod going back together.
« Reply #191 on: March 14, 2023, 09:53:15 PM »
 I went out after dinner and cut up an old chain guard, I shortened it and welded a bracket on in a different place. The barn mud and film cleaned off with some spray cleaner and 0000 steel wool. A little silver paint marker touched up the weld spots. It looks awesome.
 The Hot Rod may have a new name, in the spirit of the nugget changing names until one of them stuck, I thought this one might be "The Rat Race" since it isn't detailed really nicely and I plan to take it down the track this summer.
 The lower half loops from the center stand were cut off. I think the PO cut down a center stand that could pop under it for pit or shop use. There was a really short center stand in the load of stuff. I can't say for sure if I saved it or not. I got caught up throwing stuff away for a while after dragging this second batch of junk home.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: K1 Hot Rod going back together. The Rat Race?
« Reply #192 on: March 15, 2023, 08:18:07 PM »
 I was cleaning up the lift and putting the tools away when I decided to pre-lube the motor. I gathered the fittings, hooked it up, put oil in the cylinder and added air to the top of the oil tank. The oil pressure went up to 80 and I let off the air. Next I pulled a rocker cover to look for oil flow and when I did it went pooooffff. 
 After looking under the tool tray, I can see that the PO had connected the oil tank to the top rocker cover vent. Thus, the engine has no vent at all.  At least the motor is nice and tight and I didn't blow the gaskets out.
 That might explain a few things from when it was running, its embarrassing when something this easy gets by me. That said, talking about it might help someone else find a problem on an old bike.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: K1 Hot Rod going back together. The Rat Race?
« Reply #193 on: March 16, 2023, 01:25:52 PM »
 "ran when parked" came to mind, the Rat Race had no spark until I noticed the hanging ground wire for the Gerex ignition near the battery. After I connected it, it fired instantly. The RC header sounds awesome with a little fiberglass packing in the baffle.
 I thought now what? I need to get it off the lift for some decent break in miles except there's salt and snow and it's raining too.
« Last Edit: March 16, 2023, 01:36:59 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline grcamna2

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Re: K1 Hot Rod going back together. The Rat Race?
« Reply #194 on: March 16, 2023, 05:47:12 PM »
"ran when parked" came to mind, the Rat Race had no spark until I noticed the hanging ground wire for the Gerex ignition near the battery. After I connected it, it fired instantly. The RC header sounds awesome with a little fiberglass packing in the baffle.
 I thought now what? I need to get it off the lift for some decent break in miles except there's salt and snow and it's raining too.

Made it into a 'Runner'  ;)
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Online Don R

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Re: K1 Hot Rod back together. The Rat Race?
« Reply #195 on: March 16, 2023, 09:40:51 PM »
 It will be interesting to see how it handles with the longer swingarm. The PO had a really good fabricator, the weld work that was done is top notch. These neck bearings should get a peek too.
  I think I want to put the original K1 gauges back on it, I also have a sweet set of sandcast rebuilt forks but I hate to use them on a K1. The dragbike on the shelf has a set of lowered K1 forks that make sense, they can go on without the drop in the triple trees.
 For now, the valve cover and oil tank vent tubes are dumping on either side of the rear tire. For racing it will need a puke tank of some sort.

 The raked frame with the turbo motor will get the newer gauges and a set of bigger offset Super Sport triple trees with the short CB550 #341 forks. Since it has a side exhaust, it can sit really low.
« Last Edit: March 16, 2023, 09:43:30 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: K1 Hot Rod back together. The Rat Race?
« Reply #196 on: March 17, 2023, 12:45:22 PM »
 Today I decided to swap back to the original K1 gauges, triple trees and rebuilt forks. The 750 F0 forks are on the raked frame so I need to swap them for the 550 forks. This bike with the 4-1 can't sit as low as the turbo bike will be able to. It may even go around a slow corner once in a while.
  One issue, it seems the fork seals on the 550 forks won't go far enough in to allow the snap rings in their grooves.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: K1 Hot Rod back together. The Rat Race?
« Reply #197 on: March 17, 2023, 10:44:36 PM »
 I got the snap rings to seat into the 550 fork legs, also got the raked frame hanging on the cherry picker and took the F1 fork tubes off of it. I'll put on the F triple trees and 550 lowers on that frame for the increased offset and low stance to go with the rake, should make for a nice straight-line bike. It also has a steering damper.
 The rebuilt and lowered F forks can now go on the RC Rat Race, I have a heavily drilled rotor but might not want to get into that just now.
  The custom headlight ears on the RR don't really fit well because they sit the headlight so high it's into the gauges. I have a set of the cast aluminum ears on the raked fame, I may use those with a parking lamp bulb headlight, and run the park lamp led like a 76-up, on with the key. I'll still have a standard K0 headlight switch.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: K1 Hot Rod back together. The Rat Race?
« Reply #198 on: March 18, 2023, 03:45:46 PM »
 Never assume that anything isn't broken on a 50 year old bike.

While swapping the fork tubes I discovered both sides of the top triple were broken and it's not even a rhino horn type, I think it was a K5. The neck bearings are notchy, so I looked and they're stock. I ordered a set of roller bearings for the neck and another set of aluminum headlight ears.
  I'm using all of my best stuff on this bike and the next one will get new whatever it needs. I've got the 71 top tree and gauges that came from this bike years ago. They will go back on, if winter lasts long enough I'll put new faces on them. I have an oak gauge holder to help crimp the rings on and a set of new rings and faces.
 I also ordered new headlight trim and the park lamp headlight bulb that I have will go on it.
« Last Edit: March 18, 2023, 03:56:12 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline PeWe

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Re: K1 Hot Rod back together. The Rat Race?
« Reply #199 on: March 19, 2023, 12:00:39 AM »
Check that the lower triple is OK and straight tube for steering head.

I have one planned for a build. Noticed that lower bearing race was cracked. Easier to remove it for tapered bearings I thought.

Could not stop thinking about why it has cracked. It must have been a collision.
Noticed the tube looked strange just over the lower bearing. It looked stretched with plastic deformation. Could see it was slightly bent.


I had to order a better. I needed a euro version with oval "seat" for steering lock.

Internet is full with version with round ones, probably US.

Found an OK one in Netherlands. The difference is clear when comparing them.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967