Topic: 1975 Supersport cafe

[Greenducky55]

Hey guys this is kind of a catch up to my project that I am still doing some finishing touches on

1975 cb750f bike had been sitting in a friend of a friends shed for a few years my buddy bought it for 300 from him then it sat at his house for 6 months while he was buding his XS650 bobber and his XJ750 café. he had bought 2 more motors for it a 75 super sport motor, and a k1. the bike had a f2 motor in it. along with a hardtail frame and some other goodies. so with the K1 motor and a few more parts I took it off his hands for 500.
here is mostly how she came home to me minus the bars and working electronics the original ones had been eaten by rats.(go figure)



then I got the tank a sea and some of the basics off to see the motor covered in mud and rat turds

[Greenducky55]

then I decided to attempt to build my own seat pan... didn't turn out how I wanted maybe one day ill try again





and that's as far as I got on it I wasn't happy so I went ahead a bought a carpy seat in the end

got my hid bulb and turn signals wired and mouted along with a projector headlight off of fleabay that I ended up not caring much for


got my rear sets semi mounted

[Greenducky55]

next I got my clip ons fork brace and progressive fork springs installed


she was starting to look more like a café I could be proud of and what I had imagined also my side covers had came in didn't line up perfectly sadly maier plastic go figure


got my KOSO DB-01R gauge in and wired not yet mounted at this point along with pamco ignition coils ect and all new wires on the bike used the simplified chopper diagram to do it

[Greenducky55]

then we attempted to start her and while she did start there was a tone of bad noise coming from the top end. ended up pulling her apart to find that the cam chain guide had been destroyed. so due to this I popped open my K1 motor and decided to build whichever of the 2 had looked the best inside.
the F2 motor was done cylinder had been gouged by the cam chain pretty deeply, I pulled the cam to find the riding surface had been chipped and ruined as well. pulled the jugs they looked decent along with the pistons and crank, though the sump was full of metal bits and rubber I decided to scrap the f2 and work on he k1 with afer pulling was basically prefect inside. minus a little sludge.
so I bought one of the famous flea bay 836cc piston kits


a good ol pile of parts from cycleX



really the only pics I have of the motor building process. I had the cylinders bored by a local shop and I did the rest. all new crank and rod bearings hd cam chain new gasket kit head and cylinder decked all buttoned up and ready to install

[Greenducky55]

got the frame all cleaned up along with some brackets and ect cut off shaved the upper triple tree, painted the frame rusto metallic black. got my new levers in along with the brake and clutch mc. also new tapered neck bearings.

fork legs painted with duplicolor wheel paint

ordered my paint ended up not using the clear and a one shot pinstripe paint instead vintage burgundy pearl, midnight black metallic and oneshot gold stripe


my second tank being prepped for pain. the original tank the previous owner had shaved the emblems off by denting in the tank and then bondo like a mofo. well when I stripped the paint basically the whole thing was bondo so I bought a diff one. much less bondo work on this one


my grips that I dyed using RIT


our makeshift garage paint booth

my buddy keeping it safe with harbor freight masks

end result of days and days of painting

[Greenducky55]

good ol spark plug trick for the chin oiler

new tired mounted on the degreased and cleaned like a mofo wheels

drilled rotor

the very appropriate tail light lol

carbs rebuilt and painted

engine back in the frame and getting everything wired back up and mounted


and the original end result I love my stainless pipe!

[FrankenFrankenstuff]

Well friiging done man!  I like the headlight idea.

[andy750]

Looks great love the gold valve cover! Very cool. How does the bike run!? 

cheers
Andy

[Greenducky55]

had to rock her for haloween!

so that was the end until I was just never happy with my carbs one day they would run great the next id hate them again rejetted them multiple time played with needle clips pilot jets main jets I was just over it. so I sarted thinking a fuel injected CB would be the bes of both works right!
 
kind like this set up from jwebsterdesigns

so I bought me some GSXR throttle bodies a fuel pump pressure regulator go a base tune from jwebster as well for a microsuirt unit. got the bodies mounted with a little rigging

then I decided now wasn't the time for this set up I pan to come back to it using my other 750 I have as the gunie pig lol. the limited space makes it complicated and I didn't want my bike down for any longer I want to ride her
as or right now I am waiting for funds to order a set of mikuni rs34's cycle x charging system and a few other goodies. so I can be happy with her for now, hopefully those should be here in the next week or so and I can get it all up and running

[Greenducky55]

when she wanted to she ran amazing andy750 but either one of my choke plates would fall off of the pin and block the intake or she would idle great cold but hot would idle high ad eventually come back down, I checked the advance unit have brand new carb boots just if she would idle good at temp it would have very poor throttle response. I think the pods the 4-1 836 ect plus maybe I missed something on my rebuild of the carbs just cant ever make them happy and I know everyone says put the air box back on. but im not going to listen lol. plus I never had one

[Jerry Rxman Griffin aka MuthaF'er]

Good job so far, there's always something to spend time and money on. Keep us up to date.

Looks like an earlier F with the nylon rear master cup instead of a F1

[Greenducky55]

Orderd the mikuni rs34's from cyclex today well see how she turns out. Should be here by the end of next week

[Greenducky55]

KAPOW!


got my new carbs in yesterday and got them installed today took a little diff approach than some others on here as far as the carb boot issue.

I actually bored the carb side of my boots out using my dremel with a metal bit enlarged one on the motor stock size next to it I have 2 sets so luckly it came out good lol.

all 4 bored boots mounted they are not pretty but they work well so far

all mounted up sleeved my fuel line with some braid I had


 sadly it is raining so I cant mess with them too much and my buddy has my sync gauges. I did start her up with them on with making no changes and had to use the choke to start her but other wise she ran ok. (my first set of carbs required no choke 2nd set did.) have to get used to the flat slide rattle lol.
a few issues I had installing them not major but took a little time.
-the pull cable was a pain to get installed minimal space between frame and the bracket. but once installed no binding so all good with me.
-the fuel line on the rs 34's is 3/16th but what I did was hooked the 3/16 to the carbs then to the brass tee that comes with the carbs. then I hooked the 1/4" line from the tank to the filter and then 1/4" line to the tee was a squeeze but seems to be working great. hope to have a good report on them on Monday or Tuesday its raining the next few days and I gotta work all weekend.
at idle she may have been a bit lean but I have not messed with the fuel screw yet or anything else. want to wait till I can get her nice and warm with decent weather plus I still don't have any air filters yet.

[Greenducky55]

still with the 2nd set of carbs after I got them mounted up a little lean on the mains but had that changed. slides on this set are cut they work great even with pods where my others hated them. idled great once I got them synced up and on the street ran great. but I had already orderd the mikuni carbs which should hopefully run better anyways

[Greenducky55]

Got my rs34 mikunis pretty much dialed in. I may need to swap the pilot jet I'm still playing with the fuel screw. There is a spot that if you pull it too hard it won't react due to the size of the carbs but overall I love them and are alot happier at freeway speeds with the pods.