1979 Cb750k

[46rocketrod]

Hello there, I'm 21 years old and I have recently purchased my first bike project. I've had different bikes in the past but this is my first actual build. Earlier this summer I bought a 1979 cb750k and I'm making it a cafe racer. I'm needing to know from someone who has worked with this bike before to help me out with some ideas and info such as what front ends would fit painlessly and different wheels that would fit. I'm currently working on rear sets and I was wondering what other people have done just so I could get an idea of what to do. Thanks all for the help!

Also I'm having problems with two cylinders filling up with gas and fouling the plugs very quickly. Does anyone have an idea of what could be wrong? I have had them rebuilt and rejetted and i have drove it and it does run fine once running

 

[18Bravo]

Sorry I can't answer any of your questions. That does look like it's going to be a great bike. I just bought one last week so I have a question for you: Did you swap out the wheels for those from an earlier CB? If so, what year? Mine are Comstars. I know that generally I could make most work, but I'm currently without a lathe so I'm unable to make my own spacwers. Oh, one more ; which seat is that? The proportions are very nice.

 

[xb33bsa]

that is a good looking project
there is nothing wrong with the front end,really,correct fork springs set up for your weight and some race tech valves will do wonders a fork brace to finish
lacing up some alloy rims adds class and improves handling and suspension a bit because of less unsprung weight and less rotating mass
find a stock airbox you will never get it tuned with those cv carbs and pods
spend your money on some VERY GOOD shocks out back, hi quality brake line up front
and put in new frictions front and back
check the swingarm bearings and steering stem bearings service or replace if needed
you will be way more comfortable and have better control of the bike(for street riding) if you get some superbike bars+they just look better than silly clubman's
do NOT lower the bike,if anything you want the bike sitting slightly taller than it is now
this is for good handling and cornering clearance when lent over

 

[46rocketrod]

Thanks 18Bravo, The rims are the stock 79 rims. I think since it's the K model it had spoked rims but I could be wrong. I'll have to look to see what brand the seat pan is because i can't remember off the top of my head.

 

[46rocketrod]

Thanks a bunch xb33bsa. That will help me a lot with it. I would like to get some clip on bars and do away with that mess on top.

 

[Redliner]

The current tyres look pinched. There seems to be some obsession with getting the largest tyres one can fit onto a wheel, as I rarely ever see correct sizes installed. Rarely.

The rim will have the size on it. Check that the tyre manufacturer's recommended rim size is the same.

And the plenum/pre-plenum is a must. It offers the best performance. Get a new air filter with it. Check what size jets are installed.

DOHC's have a lot of leaky spots. It's common and should be easy to mend.

As for the fouling plugs, get the air box first. While the carbs are off do the basic stuff. Set floats, clean and replace float needles/seats, see what jets are installed, etc.