Topic: Dr Rockso's K0 cb750 cafe (**breather problem)

[Dr Rockso]

i figured i should just make my own thread on my build instead of coming up with a new one every few hours

anyways heres the story

I've had more bikes than i can count , the latest being a Vulcan 500 which simply didn't have enough oomph , I've kinda gotten worn out on the whole cruiser thing so i sold it and decided to find something a little sportier . don't really like sport bikes mainly because of the position ....and the fact that if i ever bought a sport bike all the plastic would be off of it before i even got it home so whats the point . so i went with the good ol CB750. it's a 70 K0 with a 72 engine , picked it up for $500 , which looking back on was too much , especially since it didn't have a title and barely ran , but I'm super impatient and none were showing up on the classifieds near me . i got a new title thru ITS and started ordering parts . so far I've :

changed forks twice ( thanks Kevin & Doug_id )
rebuilt the front brake caliper
rebuilt the front master cylinder
added stainless steel brake lines
replaced front wheel bearings
replaced front tire
new speedo cable
new tach cable
new clutch cable
new headlight ears
fixed a lot of wiring
added pod filters
added cafe seat from hotwing on ebay
emgo tail light
new rear tire ( not on yet , need to burn the old one off )
added side covers
installed dyna S ignition
installed dyna green coils

I'd like to get my hands on a gs450e tank , i borrowed my friends and it almost fits ( i have a hammer that says it fits ) . heres some pics , from start to where it is now (and a few photoshops of paint and other junk ) enjoy

the day i bought it

ugly off , cafe on

with my friends tank

more taken today



heres two photo shops
flat black




now for some questions ,

#1. does anyone know the name for the handlebars i have ? i really like them but can't seem to find new ones anywhere , z1 (who rules by the way ) is out of the emgo ones that look similar .

#2. I'm running pod filters on it , I've never run these on anything before , am i supposed to oil them ?

#3. since i put the pod filters on it's been running really lean , it'll barely rev unless i turn the choke on , I'm going to try going up a jet size . i pulled a bowl off to check out the numbers on the main jet and lucky me , there aren't any , just some little star and ISO anyone know what size these are ? i can't order new jets till i know what i have .

thanks for checking out my bike , and I'm sure you'll see me rambling in here about "dough hole" , i was going to name it "money pit" , but it's already taken my my triumph

[supersport]

pod filters should be oiled with air filter oil, ususally found at auto parts store. 

[Dr Rockso]

i know you oil the foam ones , but these are the stainless mesh ones , same deal ?

[ScottB]

I believe most after market filters come pre-oiled although you should make sure yours were.  Usually there is a residue left over on your fingers after you touch them.  You can buy K & N filter oil just about anywhere for cheap insurance.

[Dr Rockso]

just to clarify , i have these filters , doesn't really seem like theres any way to oil them aside from just dumping it on , it's just stainless mesh

[Daves_76_SS]

Yup, K&N filter oil.  You spray it on.

[c_kyle]

They're European bars.  They're $15 at http://www.ricepaddymotorcycles.com/specials.html.  Who say's a cafe must have clubmans or clip-ons.  I'm running the European bars too.

[Geeto67]

most toher places you will find those bars refered to as superbike bars. I run a set on my cb750 and they are hella comfortable.

Those stainless steel mesh pods are usually made by emgo and are garbage (and I am pretty sure you don't oil them either). Personally I recommend a stock airbox with K&N filter replacement, but real K&N pods will also do the trick.

I also recommend you putting some kind of fork brace on that front as cb750s without one have evil handeling. You can grind the rivits off your stock fender and use the mount as a brace until you find something better.

[andy750]

Bikes looking good DrRockso and I also like those bars. Very nice!

cheers
Andy

[Bodi]

The little star may be a stylized K (keihin) and the ISO may be a number - ie 120? Are you sure they aren't? Converting to pods is more carb work than just upping the mains, there are plenty of jetting guides here.
If the pods are really just stainless mesh then no oil, but tyen they are just gravel stoppers rather than actual filters. Most pod filters (ie K&N name brand ones) have a cloth or something that looks like layers of gauze sandwiched between metal meshes, these need oil. Get a K&N "filtercharger" kit and follow the instructions, the pods should be cleaned and oiled every year or two (or more often if you ride hella mileage or in dust storms).
The bike looks great! Ditto on the fork brace though.

[Dr Rockso]

i'm for the most part out of money at the time , i can put the stock air box back on if these filters really do suck as much as everyone says they do , i really like the look tho and don't want to shell out $120 for k&n's. as far as the fork brace goes i don't have a fender to make a brace out of , i have one for the k0 front end that came on the bike , but theres a k6 front end on there now . i placed an ad in the parts wanted section for a beat up k6 fender but no one has replied ,i'm also planning on adding a damper . the jets really do look like they say iso , i guess it could be 150 but it really looks more like an S .

[Dr Rockso]

i put the stock air box back on , it's almost ridable now . still needs alittle adjustment . i might need to adjust the clutch alittle too it seems pretty easy to miss second . but good god this thing can move ...compaired to the vulcan 500 anyway

[Dr Rockso]

anyone else having problems with their throttle responce ? mine doesn't like to de-rev right away when i let go of the throttle . nothing is binding and i adjusted all of the slides so they're all the way down at idle , it also has alittle trouble right off the line , but then all of a sudden it's like a bat out of hell , if i'd kept on it it might have lifted the wheel alittle .


also i'm still looking for a junky fender i can take the brace out of , anything that'll fit on a 76 front end , if you've got one laying around i'll gladly purchace it from you (provided it's cheap)

[Dr Rockso]

update , i fixed my oil lines but now i'm having a problem with oil coming out the breather tube ontop of the oil tank . heres what i think , it flooded ALOT and the oil is looking pretty thin , i think when i hit the brakes it's actually sloshing out the breather , even tho the oil level is pretty low . so i'm going to change it out . anyone else had this problem ? is there something else i should be looking for ?

[dt77]

Those Euro bars are look NICE on that bike.  Love 'em.  Might have to change out mine now.  I found 'em on:

www.mikesxs.com

[Dr Rockso]

yeah , it's a real comfortable position and i think it steers better with em .


you know anything about my breather problem ?

[Roach Carver]

pm sent. The filters you bought are paper element which are fine for a while but just like all paper elements, they are not reuseable. No oil either.

[v4hor]

update , i fixed my oil lines but now i'm having a problem with oil coming out the breather tube ontop of the oil tank . heres what i think , it flooded ALOT and the oil is looking pretty thin , i think when i hit the brakes it's actually sloshing out the breather , even tho the oil level is pretty low . so i'm going to change it out . anyone else had this problem ? is there something else i should be looking for ?

I had a similar problem with my K2.  It's been about 8 years but I think the deal was that the breather hose coming off the valve cover was pinched between the frame and swingarm causing pressurization in the engine and back up through the oil tank.  The oil tank would then overflow spitting oil on the back wheel and tire.  Besides the obvious problem of oil on the tire I would assume that the engine wasn't getting properly lubed.  I would check all your breathers and oil lines to make sure they are flowing freely.  Good Luck

[flatblack]

The good doctor brought his bike over this afternoon and we got it mostly straightened out:

1. Pulled the carb rack, cleaned out all the jets. Little bit of gunk, not much. Set the idle mixture to spec.
2. Set the float levels to spec, they were all over the map. Bowls had a little grit in them; I've seen worse.
3. Put new clamps on the carbs, front and rear.
4. Took a turn out of the throttle return spring to tighten it up. Pull cable is pretty new and very smooth. No push cable.
5. Synched the rack with a Morgan CarbTune.
6. Lubed the rack linkage, dialed in the idle.

Bike is much sweeter now. No leaks at the carb boots (prolly weren't any before...), idles smooth, revs well and seems to want to idle again after high revs.

Bike still wants to blow oil out of the tank. Crankcase breather lacks a hose; there's a little steam/smoke coming out of it. After an oil/filter change, I think it'll be okay. The oil in there right now probably has some water and/or fuel in it (what's coming out the overflow is pretty thin) and when the engine gets hot, it's returning vapor to the tank.

Not a bad afternoon, all things considered. Happy to help, Doc!

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[Dr Rockso]

thanks again man , never would have got it done without you

[flatblack]

thanks again man , never would have got it done without you

Yeah ya would -- woulda just taken a bit longer.

Happy to help.  Keep me posted on what you do to that bike!

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[Blaize]

Hey if you are still searching for a fork brace I have a fender from my k4 that you can just about have. I could grind the rivets and send you just the brace or you can have it complete. It i in reasonable shape, but I got a super sport front end and it came with a fender so I am using that one.. Its yours for the price of shipping if you want/need it.

[ScottB]

Dr.,

If you could give more information on ITS title I would appreciate it.  I tried looking it up on Google and came up with nothing.  What was the approximate cost, time and process to get a missing title through them?  In my state it is a huge PITA and I know I'm not the only one to have purchased a bike without a title.

[Dr Rockso]

i no longer need a fender , thanks anyway tho .


scottb , go to http://www.its-titles.com/firefox/index.htm theres a few forms you print out and then fill out . then you take them to a notary , they notarize them and then you mail them or fax them to its . it cost me $90 and i had a title in about 10 days . well not exactly a title , mine came in from guntersville alabama , it was a state issued bill of sale because they don't title bikes that old in alabama i guess . but i took it to my dmv with all the paperwork its sent me and they had no problem titling it to me in virginia . hope that helps


oh yeah , mine is a 1970 and on their site it says 1974 or older and 1991 and older , for 1991 and older they actually title it in your state and you get plates , so the price may be alittle different .

[Dr Rockso]

update

ordered my gs450 tank and it should be here soon (watch for new pics sometime this week)
got the bike inspected , of course the wire to the front brake light broke as soon as i pulled it into the bay . luckily the inspectors at the shop i go to don't seem to know anything about motorcycles so they always pass me . i did notice that my front end hops up and down slightly after i hit 50mph or so . i'll take the wheels in to have them balanced sometime durring the week  .it's really starting to come together .