Author Topic: 78 750F Chopper/Digger  (Read 73228 times)

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Offline SOHC Digger

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78 750F Chopper/Digger
« on: April 28, 2010, 03:59:42 pm »
I have been working on this bike on and off for about a year.  I finally decided to start my own thread to show my progress to anyone who may be interested.  The donor bike was a 78 750F (as the thread title would imply) that didn't run, had frozen carbs, title MIA, etc.  However, the engine turned over freely and I am a sucker for dual disc front ends.  Picked it up for $400.  Got it home, took some pics, and tore it apart.
« Last Edit: July 24, 2015, 04:07:36 pm by SOHC Digger »

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #1 on: April 28, 2010, 04:02:49 pm »
Early April.  Rigid frame with original front end and stock comstar wheels.  The frame has about 40 degrees of rake.  I gotta say, I do love the look of those wheels too.

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #2 on: April 28, 2010, 04:04:34 pm »
Engine cases back from bead blasting.  If anyone in the Chicagoland area is interested, this guy Jeff that I work with does killer work.  He charged me $50 to bead blast these cases and they came out beautiful!

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #3 on: April 28, 2010, 04:05:53 pm »
Mid-April.  Found this diamond tank on craigslist for $150!

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #4 on: April 28, 2010, 04:08:52 pm »
Today, notched out the neck gussets a little to accept the diamond tank.  Took more pics.  Gave my engine cases a bath in the master tub (don't tell my wife!) in preparation for painting as soon as the temp breaks 65 consistently.

Offline captaincrash80

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Re: 78 750F Chopper/Digger Project
« Reply #5 on: April 28, 2010, 06:11:50 pm »
Good start man, I'll be keeping an eye on this one.

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Re: 78 750F Chopper/Digger Project
« Reply #6 on: April 28, 2010, 06:15:43 pm »
COOL! ;)

Offline 1080

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Re: 78 750F Chopper/Digger Project
« Reply #7 on: April 28, 2010, 08:03:08 pm »
SOHC Digger, I like the tank 8)
I always call them Prism or Prismic tanks.
Made by Denver's Choppers.
I always had people say " I like your coffin tank" ;D

I am changing a few things this year on my chopper.

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #8 on: April 29, 2010, 07:34:27 am »
What are you changing on yours?  I love the Savior frame look, but I have heard they handle poorly; any truth to that?

Yeah, I call them prism tanks or diamond tanks.  I think I've become a bit of a tank snob because I've gotten the whole "nice coffin tank" thing with my other bike and I have to keep from lecturing on about the differences and making myself look like a jerk.

Offline Ogri

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Re: 78 750F Chopper/Digger Project
« Reply #9 on: April 29, 2010, 07:35:07 am »
SOHC Digger, I like the tank 8)
I always call them Prism or Prismic tanks.
Made by Denver's Choppers.
I always had people say " I like your coffin tank" ;D

I am changing a few things this year on my chopper.

+1

This is a 'coffin' tank, similar but squared off at the front and back:

http://cgi.ebay.com/ebaymotors/VINTAGE-CHOPPER-Coffin-Fuel-Tank-PANHEAD-_W0QQcmdZViewItemQQhashZitem563956c2caQQitemZ370329174730

Offline 1080

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Re: 78 750F Chopper/Digger Project
« Reply #10 on: April 29, 2010, 10:03:49 am »
A few times, both guys & girls have said "Nice Harley". ;D

I'd reply "It's a Honda Davidson" ;)

My low ground clearance because of the position of the dual side stands is a limiting factor. I usually cut the corners in a straight line. I often ride double up & have no handling problems there. I also have to watch for road bumps & dips.

I am adding a different fender, fork brace, polished the disc centre & caliper mount, & there will be a few other details to clean up as well.

Offline HavocTurbo

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Re: 78 750F Chopper/Digger Project
« Reply #11 on: April 29, 2010, 10:33:50 am »
What color?

I have a wicked candy green or caramel powdercoat that might be cool.
'48 HD Panhead - Exxon Valdez
'78 CB550K - Fokker CB.3
'78 Honda CB750K - Mavrik
'80 Yamaha XS850G - Kanibalistik
09 XL883L - No Name

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #12 on: April 29, 2010, 10:42:56 am »
I saw this bike on Cyclexchange's for sale postings and fell in love with the engine all together.  I know it might be copying somebody else's idea, but imitation is the sincerest form of flattery.  This guy did a nice job and I hope mine comes out as nicely.  So, the cases will be Hemi-orange engine paint with low-gloss black and chrome on other parts.

Offline HavocTurbo

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Re: 78 750F Chopper/Digger Project
« Reply #13 on: April 29, 2010, 10:56:52 am »
low-gloss....

like a satin perhaps?

I'm digging i know... sorry.  :'(
'48 HD Panhead - Exxon Valdez
'78 CB550K - Fokker CB.3
'78 Honda CB750K - Mavrik
'80 Yamaha XS850G - Kanibalistik
09 XL883L - No Name

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #14 on: April 30, 2010, 06:52:12 am »
I'm just quoting what the paint can says.  Probably will be a satin finish.

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #15 on: May 04, 2010, 03:22:10 pm »
Painted my cases today.  They are more orange and less red than these pics imply.

Offline HavocTurbo

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Re: 78 750F Chopper/Digger Project
« Reply #16 on: May 06, 2010, 03:08:00 pm »
Nice!!!!  8) 8)
'48 HD Panhead - Exxon Valdez
'78 CB550K - Fokker CB.3
'78 Honda CB750K - Mavrik
'80 Yamaha XS850G - Kanibalistik
09 XL883L - No Name

Offline JLeather

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Re: 78 750F Chopper/Digger Project
« Reply #17 on: May 06, 2010, 03:53:29 pm »
I love the Savior frame look, but I have heard they handle poorly; any truth to that?

Savior frames got a bad rap for a couple reasons.  Biggest problem is no one took care of them.  You've gotta lube up the bushings in the back end every so often so they don't wear out.  Once they wear, then the rear gets sloppy and handles real funny, but when they're right I don't notice anything weird.  I've had a couple, this was the last one that met an unfortunate and untimely end when I sent it out for some frame work and it never came back.  Now I do everything myself  :-\



There are also lots of frames people call "saviors" that aren't.  Several companies made plunger frames where the axle trailed behind the springs.  In a real savior frame, by Amen, the axle goes through the plunger.  Much more contact area to keep it from cocking.  Anyway, though, as a long time chopper builder said "Build it the way you want, then learn to ride it".  My first chop was a savior, learned to ride squirley bikes on it and never looked back.

Nice stance on the bike BTW.  The way the backbone flattens out under the seat makes me believe that's a C&G frame.  

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #18 on: May 18, 2010, 10:31:01 am »

Nice stance on the bike BTW.  The way the backbone flattens out under the seat makes me believe that's a C&G frame.  

Do you know much about the C&G Frames?  I have tried researching them and found nothing.  I cannot find any identifying marks on the frame.  Is there anything more you can tell me about these?  Thanks.

Offline JLeather

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Re: 78 750F Chopper/Digger Project
« Reply #19 on: May 19, 2010, 07:31:47 am »
I had a CB350 frame that had the same flattened-tube under the seat like that.  Was told it was a C&G.  Doesn't really matter, it's a good lookin frame.

Offline Flying J

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Re: 78 750F Chopper/Digger Project
« Reply #20 on: May 19, 2010, 07:17:34 pm »
Im watching this one

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #21 on: May 21, 2010, 06:51:07 am »
So yesterday I cleaned my crankcase surfaces of any remaining adhesive etc, and started the assembly process.  I got the lower case assembled fine but when I put the final drive in the upper, that's where my evening got nasty.  The last engine I did was a 77 CB750K and there is a little plate that bolts right next to the final drive.  I cannot find this plate now.  I tore my garage apart looking for it.  The shop manual that I have is for '69 thru '78 so it's kinda generic, but it shows it in there.  I look at the "Official Honda K8 F3 Manual" and there is no mention of it anwwhere and it's not in any pictures.  So, maybe I tore my garage apart for nothing.  I posted a question and am waiting for some experts here to chime in before I move forward.

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #22 on: May 25, 2010, 05:55:43 pm »
Thanks for everyone who chimed in about the oil plate.  Apparently Honda eliminated them by the time my engine went through production.  Crankcase halves are loaded and ready to mate (Where have I heard that before?)

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #23 on: May 26, 2010, 07:16:15 pm »
Put my case together today, went to put the top bolts in and they started to bind before they seated.  Son of a...  So I took the cases back apart, cleaned all the Permatex back off, tapped the bolt holes, and repeated the process.

Offline SOHC Digger

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Re: 78 750F Chopper/Digger Project
« Reply #24 on: June 03, 2010, 01:06:30 pm »
Got my clear points cover from frankenbike today!  Holy sh*t!  This is the best money I have spent on my bike yet!  This thing is super-high quality and looks killer.  I took some pics without my ignition, and some with the dyna ignition plate in there.  If you are even thinking of getting one, do it!!!  I will be getting more just to have a couple colors to choose from.