Author Topic: 1978 CB750F3 Build/Project  (Read 14492 times)

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Offline Steven.Burns

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1978 CB750F3 Build/Project
« on: October 11, 2011, 10:43:44 PM »
So I finally bought myself my long time dream bike. CB750F2 of course!  I've always liked the look of these bikes and liked them a lot better when they are cafe racers.  As soon as I got my first job my dad made me save money to buy a car instead of a motorcycle. Yeah bummer, I know.  Then once I bought myself a car I saved as much money as I possibly could and bought my CB750.  Now Since I spent most of my money on my bike I gotta start saving for the Cafe Racer build. I'll Keep some updates when I start building.  ;D

Won't let me post a pic right now. I'll Post some pics asap
« Last Edit: November 16, 2011, 09:01:23 PM by Steven.Burns »
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #1 on: October 15, 2011, 03:23:17 PM »
Had a cracked stator cover so I bought a old oxidized one. Cleaned it all up with some 400 grit sand paper, scotch-brite and elbow great. Just finished painting it and Installing tomorrow.
« Last Edit: October 16, 2011, 10:32:08 PM by Steven.Burns »
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline lucky

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Re: 1978 CB750F2 Build Project
« Reply #2 on: October 15, 2011, 03:53:39 PM »
So I finally bought myself my long time dream bike. CB750F2 of course!  I've always liked the look of these bikes and liked them a lot better when they are cafe racers.  As soon as I got my first job my dad made me save money to buy a car instead of a motorcycle. Yeah bummer, I know.  Then once I bought myself a car I saved as much money as I possibly could and bought my CB750.  Now Since I spent most of my money on my bike I gotta start saving for the Cafe Racer build. I'll Keep some updates when I start building.  ;D

Won't let me post a pic right now. I'll Post some pics asap

I know you won't want to hear this but you have a great dad giving you good advice.
Car first, for when its cold and raining and you want to date the girl she will feel safer too.
I wish I had ,had a good dad to give me good advice. You are lucky.

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #3 on: October 16, 2011, 10:27:15 PM »
Finally got a picture of my bike up on here.
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #4 on: October 17, 2011, 05:53:34 PM »
Finally got my stator cover replaced. Ended up being way easier than I expected. The only thing that sucked was I dropped a washer behind the starter gear. Took me about 15 min to get it out then after everything was ready to be tightened down I realized I forgot to put the new gasket on.  Before you take off the stator cover, put something under the left leg of the center stand so that the oil ill drain out of the stator cover. Also loosen the three center screws before you take it off. When I took it for a test ride and when I got back I found out that I have a small oil leak somewhere. Thats going to be fun to figure out. Gotta get my engine all cleaned up.
« Last Edit: October 17, 2011, 09:42:44 PM by Steven.Burns »
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline hapakev

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Re: 1978 CB750F2 Build Project
« Reply #5 on: October 17, 2011, 07:19:20 PM »
Damn that bike ic clean!!  You might catch some sh!t from the guys for tearing up a stock beauty like that, but probably not since its an F2 ;D  Its always great to see another F build.  What are the plans?
Smoking Jack
1978 CB750F(ish)

"Keep moving forward, until you can no longer move" KP

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #6 on: October 17, 2011, 07:29:20 PM »
Thanks!  For now I'm going save money and slowly clean it up and make her run real nice. But for the long run, I'm going to cafĂ© the @#%& out of it and rebuild the motor and maybe even put an 836cc kit on it. I feel kinda bad chopping her up but I'm still going to do it. The funny thing about this bike is that my dad had the exact same bike when he was my age in the early 80's and I didn't even know it.
« Last Edit: October 17, 2011, 09:33:35 PM by Steven.Burns »
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline hapakev

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Re: 1978 CB750F2 Build Project
« Reply #7 on: October 17, 2011, 08:35:05 PM »
Thats awesome!
Smoking Jack
1978 CB750F(ish)

"Keep moving forward, until you can no longer move" KP

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #8 on: October 19, 2011, 10:35:40 PM »
Finally decided to clean up my engine. It had a lot of oil and grime on it.  I just bought a gallon of Simple Green and used a spray bottle, I let it soak in for a few minutes and hosed it off. I ended up doing that twice and let me tell you, It looks hell of a lot better now.  Somehow I got some Simple Green on my speedo and now is has a nice blur on it :/ Also I noticed my bike was running really rich so I checked my plugs and they were BLACK with carbon build up.  So I got looking around to see why it's so rich and checked my air filter and it was pretty dirty so I just ordered a K&N Air Filter   :D  Hopefully that does the job. Maybe this weekend I'll take a look inside the carbs
Another thing I couldn't figure out was my damn running light. I checked the bulb and its fine but I checked the wire for it and its not get any current. Tried to chase it to the headlight but couldn't find the wire in there. I'm thinking there is a shortage or it's just disconnected. I'm lost, any help on this??
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline hapakev

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Re: 1978 CB750F2 Build Project
« Reply #9 on: October 20, 2011, 06:47:55 AM »
no current or no voltage?  you cant measure current on a DC (battery) system unless you measure it inline, ie break the connection and put the meter leads in between the wire and bulb.  If you are talking about voltage, you may have a broken wire.  The easiest way to find that is to keep checking for voltage and when you find a spot with no voltage, back up to where you have voltage and then you have the break.
Smoking Jack
1978 CB750F(ish)

"Keep moving forward, until you can no longer move" KP

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #10 on: October 20, 2011, 07:12:57 AM »
There is no voltage. I followed it as far as I could but I don't know if it goes to the headlight. I opened it up but couldn't find it in there, if it even goes to the headlight. Thinking about just rewiring the whole bike since the turn signals and horns are disconnected too but I'm not to good as an electrician. We'll see what happens, I might just have my dad's friend do it since he knows all about that stuff.
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline hapakev

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Re: 1978 CB750F2 Build Project
« Reply #11 on: October 20, 2011, 12:59:05 PM »
There are wiring diagrams out there to download.  They are color coded, find one and just take your time reading it.  Make sure you get the one for the 77-78 cb750f2 (or f3).

By running light, do you mean the lights in the gauges?  If its on the "dashboard" there isnt a "run" light for these, just warning lights and if those arent getting voltage-thats probably a good sign.
Smoking Jack
1978 CB750F(ish)

"Keep moving forward, until you can no longer move" KP

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #12 on: October 20, 2011, 06:24:10 PM »
My tail lights running light its getting voltage. The brake part works just not the running light. I checked the bulb and both filaments are fine. I'll try the wirng diagram and see if I'm smart enough to figure it out. Im definitely a newby with all this stuff, it's my first bike and I have little mechanical experience but I'm a quick learner.  :D
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline MoMo

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Re: 1978 CB750F2 Build Project
« Reply #13 on: October 20, 2011, 06:30:07 PM »
You mean tail light?  If so, check for 12 volts at the brown wire, which is usually under the seat...Larry

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #14 on: October 20, 2011, 07:23:27 PM »
I checked the brown wire with the thing with the needle and light. I don't know what it's called. It didn't light up and I don't know where it leads from under the seat and couldn't find the solid brown wire in the headlight housing.
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline MoMo

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Re: 1978 CB750F2 Build Project
« Reply #15 on: October 20, 2011, 09:08:20 PM »
Not sure about your model but some Hondas have a tail light fuse.  The brown wire usually runs off the ignition switch.  The manual should be available for download on this site...Larry

Offline hapakev

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Re: 1978 CB750F2 Build Project
« Reply #16 on: October 20, 2011, 11:07:49 PM »
Oh Ok that makes sense, running light.  Check the fuse and then the wire from the fuse to the light, it may have a break and need to be replaced.
Smoking Jack
1978 CB750F(ish)

"Keep moving forward, until you can no longer move" KP

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #17 on: October 24, 2011, 07:17:37 PM »
Still no luck on the Running light. The fuses are still good and I checked the schematic and I don't know what/where the combination switch is? Any help?
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #18 on: October 28, 2011, 02:53:10 PM »
Alright, I finally figured out my running light. It has a short at the ignition. So I'm guessing the ignition is the Combination switch, right?  Also did a few more things to my bike this week. I took off those lame ass stock blinkers that didn't even work, The PO obviously doesn't know anything more than me about electrical. The bike looks hell of a lot better than before.  Took the baffle out of my Kerker exhaust and it sounds even louder/ better than I expected. It didn't really change the low end response like I thought it would.  :)  I have no horn, so who needs a horn when you have a loud ass exhaust?
Right now I'm about to go to my dads friends house to pick up my bike with a new Barnett Clutch kit. Let's see how sore my left hand will be on the ride home from those HD springs  ;)
Changing the oil and filter tonight and going to clean the carbs tomorrow. I hope there not too nasty!
« Last Edit: October 28, 2011, 03:02:26 PM by Steven.Burns »
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline hapakev

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Re: 1978 CB750F2 Build Project
« Reply #19 on: October 30, 2011, 12:14:29 PM »
Sweet man.  I was thinking the combo switch might be the right hand switch on the bars, but it may be the ignition.  I'm not sure.  Glad you got it figured out man.
Smoking Jack
1978 CB750F(ish)

"Keep moving forward, until you can no longer move" KP

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #20 on: October 30, 2011, 03:56:27 PM »
Thanks. It actually ended up not being a short but just not plugged in the right spot.
Also went in a ride with my pops today and I definately need to clean my carbs. My bike doesn't idle anymore unless the choke is pulled. The idle is definately clogged and the main jet is probably not so great either. It's always something with these old bikes. That's what I love about them :)
« Last Edit: October 30, 2011, 04:48:00 PM by Steven.Burns »
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #21 on: November 08, 2011, 09:54:51 PM »
Alright, Since I got my bike running good for a little bit I have been riding the #$%* out of it within those few days.  Today I was about 5 miles from home and my clutch cable snapped.  I guess the old cable couldn't handle the HD clutch springs.  I just decided to try to dry shift into first and see if I can make it back home. I ended up stalling it while making a tight U turn, so I got it into neutral and pushed it as fast as i could and hopped on and clicked into first. The tricky part about the whole thing was stop signs (good thing there weren't any cops) because I basically just blew threw them all.  ::)  Throughout the whole thing I got her all the way up 4th gear.  I did actually make it home with a solid transmission, I hope.
Alright now about the new clutch cable. I have "Euro" bars right now so should I stick with OEM cable or go with the - 3.5" Motion Pro aftermarket cable?    http://www.motionpro.com/motorcycle/partno/02-0124/
Let me know your opinions, Thanks
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline hapakev

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Re: 1978 CB750F2 Build Project
« Reply #22 on: November 09, 2011, 08:40:37 AM »
I havent bought new/shorter cables.  I just route them differently, but you got me thinking about getting new ones.  I dont want to snap a cable while out riding, so I vote for the shorter cable as it will probably be cleaner.
Smoking Jack
1978 CB750F(ish)

"Keep moving forward, until you can no longer move" KP

Offline Steven.Burns

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Re: 1978 CB750F2 Build Project
« Reply #23 on: November 13, 2011, 01:35:21 PM »
I was looking at my serial numbers today and I noticed that the frame said CB750F - 22.... and my Engine said CB750E - 310.....
what does the "E" mean and does that mean my bike is F2 or F3? 
Seems like everything I read says something different.
1978 CB750F3 -Scrambler/ tracker or something of the sort  http://forums.sohc4.net/index.php?topic=97025.msg1083788#msg1083788

Offline brandEn

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Re: 1978 CB750F2 Build Project
« Reply #24 on: November 13, 2011, 01:47:50 PM »
1975F = F0
1976F = F1
1977F = F2
1978F = F3