Topic: 750F thread?

[slabbedask]

Hi guys, great thread with plenty of eyecandy!
Just a quick question. (I did post it in another thread here as well, but since it's "F"-related, this may be a better place...)
Are there a lot of diffenence between the wiring harness on a 76 F and a K from the same year? I would like to get a fresh harness for my F1, but can't find any repro ones for it. So could a K harness work, as I've seen repros for those? And are there many differences between the harnesses on US and Euro bikes? (I'm in Norway....)
Going to tear the bike down this winter to do a Cafe-inspired rebuild. It's already bored to 836 and had an engine overhaul, now it's time tu upgrade the handling/stopping. Have already got adjustable Hagons and Race Tech springs and emulators for it, and are waiting for Borrani alu wheels from Italy. Want to get a fork brace and an extra front disc. Also have the remains of an italian sport seat for it, just can't remember the name of the manufacturer....Will start a build thread when I start tearing it down....:-)
This is more or less how it looks now, with the exeption of a Viper fairing installed after the pic was taken...


Edit: And yes, a previous owner have replaced the original front with one from a K. I think it's from a K3 or something like that....

[Jerry Rxman Griffin aka MuthaF'er]

The 75/76F is probably MORE different than all the others. Only junction box on the downtubes on all the bikes. There is/was a fairly recent (last year) post about someone producing new harnesses and the 75/76 was mentioned. A little searching might produce that info. They were fairly inexpensive too. I have only seen 2 NOS -392 harnesses available on EBay in 5+ years searching. One of those is on my freshly restored bike. I paid ~ $140 to get it due to the lack of availability. 

[Don R]

looked at a 77K, it has the same appearing brake pedal tube but might be longer.

[slabbedask]

The 75/76F is probably MORE different than all the others. Only junction box on the downtubes on all the bikes. There is/was a fairly recent (last year) post about someone producing new harnesses and the 75/76 was mentioned. A little searching might produce that info. They were fairly inexpensive too. I have only seen 2 NOS -392 harnesses available on EBay in 5+ years searching. One of those is on my freshly restored bike. I paid ~ $140 to get it due to the lack of availability. 

Thanks Jerry. Hmm, looks like I better start searching....

[Jerry Rxman Griffin aka MuthaF'er]

The 75/76F is probably MORE different than all the others. Only junction box on the downtubes on all the bikes. There is/was a fairly recent (last year) post about someone producing new harnesses and the 75/76 was mentioned. A little searching might produce that info. They were fairly inexpensive too. I have only seen 2 NOS -392 harnesses available on EBay in 5+ years searching. One of those is on my freshly restored bike. I paid ~ $140 to get it due to the lack of availability. 

Thanks Jerry. Hmm, looks like I better start searching....

Your best bet may be to get a connector kit from vintageconnectors or oregon and replace all the connectors. The bullets are available as well as the plastic ones. I replaced all mine that I couldn't find as new parts so all mine are now new. 

[Don R]

Sounds like I should carefully remove the harness from the wrecked 75F I have and  bag it for future use.

[slabbedask]

The 75/76F is probably MORE different than all the others. Only junction box on the downtubes on all the bikes. There is/was a fairly recent (last year) post about someone producing new harnesses and the 75/76 was mentioned. A little searching might produce that info. They were fairly inexpensive too. I have only seen 2 NOS -392 harnesses available on EBay in 5+ years searching. One of those is on my freshly restored bike. I paid ~ $140 to get it due to the lack of availability. 

Thanks Jerry. Hmm, looks like I better start searching....

Your best bet may be to get a connector kit from vintageconnectors or oregon and replace all the connectors. The bullets are available as well as the plastic ones. I replaced all mine that I couldn't find as new parts so all mine are now new. 

Sounds like a good plan. I already found those two companies via another thread here, and they are now in my favorite folder for future shopping.
BTW, does anyone have a pic of the electrical connection box on the downpipe (at the front of the frame) on an F1? Mine's long gone, and as a "band aid fix" I've stuck a small bålastic box with a screw-on lid there. It came from the hardware store containing screws. I'd like something stock'ish looking there instead, and assume that I'll have to make it myself. (After over 35 years of building plastic models, mainly cars, I'm pretty handy at plastic fabricating...:-)
)

[RSchaefer]

Here is what I have:

[slabbedask]

Here is what I have:

Aha, so that's what it's supposed to look like! Not sure if I like the look of that much better than my screw box enough to start looking for one though... I'll see what I come up with. Thanks for the pics...! :-)

[HonderCB]

does any F owner out there have the stock black exhaust endcap/baffle for the stock HM410 exhaust that came on the F2/3?  maybe someone who bought a bike with a trash stock exhaust and swapped out the whole unit?  My bike has the stock HM410 and it is in great shape, but is incredibly loud... it doesnt bother me much, but people riding behind me complain lol.  I never have had the cap on the end of it.

If anyone has one their willing to part with let me know what you want for it and maybe we can set something up.

Heres a pic of what i'm talking about:

[david 750f]

Just a heads up for any 76 Sulphur Yellow 750F owners.. If you get Model Master Cadmium Yellow Light paint at any Hobby (RC)store it is an exact match for touch up paint..
Cheers,
David

[Freaky1]

It's been a while since I've checked in and it looks like some good things have been happening here, always love the bastard child thread! Figured I'd throw a pic or two up and show the progress of my Beast as of late, hope you enjoy.

[Jerry Rxman Griffin aka MuthaF'er]

Guys, not to compete with Don here but there is Motad discussion about F mufflers. I started a thread to see who would be interested in a new muffler. Please get the message out and have any interested parties go to sign on.

http://forums.sohc4.net/index.php?topic=115276.0

[Don R]

It's

Guys, not to compete with Don here but there is Motad discussion about F mufflers. I started a thread to see who would be interested in a new muffler. Please get the message out and have any interested parties go to sign on.

http://forums.sohc4.net/index.php?topic=115276.0

 It's cool, I haven't made any mufflers lately except the one for my F2 header on my K0 bike. Haven't finished the baffle so it's running on a tomato paste can.

[70CB750]

Subscribed.

[calikid]

been looking for this thread forever!! i have a cb750f 78'... the keihin pd42a carbs SUCK. What other carbs are compatible with our bikes and aren't such a pain in the backside??

I'll post pictures soon of my bike in here soon, redoing the wiring and refitting oil lines/custom seat/tank

[70CB750]

The engine from 78F I picked up few weeks ago came with early carburetors - like from K2-4  or so. 


Few questions to F - experts:

1. Is the 1979 CB750F compatible with the K frame?  I have K3 frame in good shape and I want to use F3 wheels with it.

2. Where is the front brake light switch located on the F? 

Thanks!

[Retro Rocket]

As long as it is a sohc engine it will bolt in the same as the early bikes....

[70CB750]

Dang, i forgot to mention swingarm. I am trying to find a swingarm to fit in the K3 frame and to work with F3 rear wheel.

I asume 77F to 79F  swingarm will work, correct?

[Tugboat]

No, actually that's wrong on a couple of points.

First, 79 is a DOHC, so basically nothing transfers to the older SOHC bikes. SOHC are 1969-1978.

Second, the F3 rear wheel's sprocket carrier (and thus, the hub) is 10mm wider than any of the 69-76 K or F bikes'. The 77/78 F & K swing arms are therefore 10mm wider to accommodate the wider hub. This is all so that the chain lines up with the front sprocket, which is 10mm offset to make room for the wider 630 chain used in 77/78. The upper shock mount on the chain side in the back has a 10mm shoulder on the 77/78 bikes to keep the shock straight (since the swing arm is wider). Your K3 frame does not have this 10mm shoulder, and therefore the lower shock mounting point on your F3 swing arm won't line up with the upper mount.

If you want to use the newer F3 motor on your older K3 frame, you'll need an older wheel and the 10mm offset rear sprocket from CycleX, along with a new 530 chain and front sprocket.

Here's my thread all about it:
http://forums.sohc4.net/index.php?topic=103649.0

[70CB750]

Thanks, Tugboat. I have 78F engine and 78F wheels. I want to use that on K3 frame.

That said - and forgive me if I am slow taking in the info - I want to marry 78F swing arm with K3 frame to be able to use 78F wheels. I am prepared and capable of to alternate the upper shock mount on the left side to accomodate the swing arm.

Also the engine came with 530 sprocket and thats what I am planning to use - the whole 530 set.

[Tugboat]

If you modify the frame you should be good. Good luck!

[Retro Rocket]

CycleX has the 10mm offset front sprocket you will need to mate too the 78 rear wheel...

[70CB750]

Thank you all.

[calikid]

Best recommendations for carbs for a 78' cb750f?