Topic: '72 cb350k4 mild custom

[johnspeck]

i've ordered shorty reverse megaphone mufflers, which i think will look a little cooler, as well as solve my muffling problem.

today, we'll get the mufflers off, and see if it runs with just the headers.  that will hopefully tell us whether the exhaust was an issue at all.

Beautiful work!  I'm trying something a bit less ambitious with mine (for now) but do need to address the same muffler situation you had.

What did you do to separate the mufflers from the headers?  Were they spot welded or mechanically fastened? I haven't begun disassembly so I'm still trying to figure out if this will be a knife or a gun fight.

i sprayed wd40 in every possible nook and cranny, let 'em sit for a couple days, then trashed the (already wasted) mufflers getting them off.  bench vise, rags, big screwdriver, bigger hammer, wood to wack against stuff, etc...

[hkelley]

Thanks for that feedback.  I don't want to take this Project Shop thread off on a tangent, but I do have some other questions.  I've started a new thread in the Other Bikes section.  I'd appreciate any info you could provide.

Removing a CB350K4 Muffler
http://forums.sohc4.net/index.php?topic=55994.0

[johnspeck]

progress report:

jetting the carbs is still a bit of an issue; overly rich mids, but i've got the carbs as close as i can without buying new needle jets (just started a new job, and money is tight for a few until i get caught up on bills).

compression is good, over 150 in both cylinders.

i'm currently dealing with two problems.

the left fork seal started leaking a bit.  at high speeds, the front end is a little squirrely if there's any wind/buffeting from cars...i'm hoping to avoid having to tear the forks apart until i have the money for new springs and emulators, so i can do the whole shebang at once.

i'm also trying to fix a fuel delivery issue with the left carb.  it seemed to starve out and sputter at high speeds/higher rpm's.  i made sure the fuel line was routed right, took a little length off the line overall.  it seemed to get better, until i was riding home from work yesterday.
i ran the gas pretty low in the tank last week, and noticed some rust, etc. when i drained  the float bowls, so i cleaned everything out.  i'll check my float levels are even, maybe tweak them a little bit this weekend, and check again that there's no gunk in the carbs.

the last big project i'd like to tackle before the end of the year is the wiring.  i want to rewire the entire bike with new wire/connectors/etc., getting rid of the stuff i don't need (turn signals).
then i'll go with a more modern headlight.

next year, a tear-down and more cosmetic resto (frame paint, etc.)

[johnspeck]

so, an update...
i've been working a lot, and the bike has been my primary transportation.  i've found a couple little problems to fix.

i replaced the gas cap gasket, which was hardened and cracked.  i also replaced the petcock with a new one.  the original was leaking and the filter had rotted away.

i installed a quick release dual shut-off for the fuel tank crossover, so i could get the tank on and off without having to drain it.  very handy!

the starter button cracked and i tracked down an exact replacement on ebay.

i scored a speedo in similar shape to my tach.  i'll install it this week.  my original didn't work.

i cleaned and painted the undersides of the fenders.  took the harness off, cleaned and re-routed the wiring under the tank.




















i always envisioned the bike to be slightly customized from stock, so i ended up refoaming and recovering the seat pan.  i also mounted a lucas-style tail light.





with the fender, light and seat finished and mounted...










i'm waiting on some smaller needle jets for my carbs, which should pretty much dial them in.  they're still a little rich in the mids as is.

i'm still going through and cleaning and polishing all the little bits.  it's an ongoing project.  

[SohRon]

Excellent thread! Great work on the bike. I do love those old 350 twins. And, thanks for all of the detailed pics - really took me back to when I had my '69 CL...

[johnspeck]

january update:

crap!

well, if you plan on running your little 350 twin hard, skip the stock cam chain tensioner assembly altogether.  i replaced mine with a brand new set-up this past june.
changing my oil today, i noticed pieces of rubber and little bits of metal in the drain pan.

and i'm diligent about keeping it adjusted.  i tried some different jetting sunday, and took it out on the freeway for a flogging.  on the way back, i noticed it sounded like my cam chain was loose, it was more noisy than usual.
giving the bike a tune up today (check points and timing, readjust tensioner, change oil), i noticed the evidence of worn rubber rollers.

looks like another tear-down sooner than later.  this time it's getting a slipper tensioner and heavy-duty cam chain.  if the finances allow, i might even pop for a set of bigger pistons, and a slight mill of the head.

i also have a 70's hooker 2-1 exhaust header i'm fitting.  just need to weld a bend so i can use one of my megaphones instead of the boat-anchor hooker muffler.


here's a recent pic.  i shaved down the bump in the seat foam, and recovered it with the old stock seat cover.  i liked the way the old cb450 seats (and the older triumph seats, flat and long) look, compared to the cafe style.



also have the option of a different front end swap if i want to, so i'm seeing what parts my pals have laying around, and thinking about what makes sense.


more info as i progress.

[johnspeck]

been awhile since i've posted.  i've been really busy.  got a new job, and i've got the bike completely apart.

one thing led to another, and a full rebuild from the ground up is well underway.

took the bike apart and kept finding issues...





prepping the frame for some grinding and welding, look what i found!





hidden behind the left passenger peg/swingarm brace bracket.

so, i scored a parts bike out at a salvage place north of here.  went in halves with a pal, so for $25, i got all the stuff i might need.

parts frame has issues, too.  water damage.







cleaned out the bad metal, welded some patch pieces, ground them down and built the area up, then welded on some additional bracing.  don't have pics of the most recent work, will do so this weekend.

started grinding tab seams and boxing in the seat rails.





also cut part of the original brace out and replaced it with something smaller and stronger, so i can better hide the smaller gel battery.







took a wire wheel to most of the frame paint.



ground down the seams to prep for welding.





tacked.



welded.



good penetration.



also figured out where to place the ignition.  cut up an old bracket, tacked and welded into place.  it'll look better when i clean up the welds.



need to take pics of the latest prgress from last weekend, but i got a piece of metal in my eye and had to go get that taken care of.

here's the most recent shot, with the rear hoop removed.



i have the rear hoop i'm going to use, a rear fender stay off a cb360.  it'll be mounted this coming weekend, and i can get to figuring out the rear fender mount.

speaking of rear fender, my starting point is the insanely cool chromed aluminum piece i scored off my pal.  never drilled or mounted.



of course, it'll be shortened for my bike.  i might have enough left over to make another chop fender.

these DID's are being laced to the stock hubs with stainless spokes and nipples from buchanan's.  scored them for a sweet deal at the salvage yard.



engine on the bench for a full tear-down and rebuild.  a basic project has turned into 'how many cool go-fast parts can we put on this thing?'

to that end, lots of goodies...



package from boretech arrived!

1mm oversized pistons.



KA slipper tensioner, tsubaki HD cam chain, composite oversized head gasket, seal kit, new gaskets, etc...



building a stripped-down harness.  a kit from vintage connections to start, and a totally taken apart stock harness.





i have the harness completely unwrapped.  going to use as much of the stock wire, cut to proper lengths and new connectors, replacing with new as needed.  it'll mostly be run through the frame and hidden as much as possible.

smaller vintage honda headlight bucket, NOS.  the metal one, not a plastic jobby.  almost a shame it'll be powdercoated.





need to take pictures of the most recent go-fast goodies when they get here...ignition from boretech, dyna mini-coils, full racing valvetrain (stainless valves, kibblewhite HD lightened springs and Ti keepers, hardened bronze guides), barnett clutch internals and springs...

the cylinders are already at the machinist, waiting for the valve stuff to drop off the head.  head and top of cylinders are getting milled, 5-angle valve job, along with the overbore and hone.

i also have the early type-1 cam and followers for it.

custom stainless 2-1 exhaust is being built as i type this.

hopefully by the end of this weekend, i'll have the rear seat hoop mounted, rear fender mounts fabbed and welded on, battery box built and sorted, along with underseat electrics tray.

then i can make my seat pan, clean up the SL swingarm i scored, and get the rest of the small bits ready for powdercoat.

still need to get the cases split, fix the kickstart assembly, and get it back together.  starter has been removed along with all related parts.

new fork seals and preloaded springs for the front end for now.  a full swap for something better this fall/winter.

there's a place locally that does brakes for industrial and farm equipment, and one of my pals has had his shoes done by them.  apparently, stoppies with drum brakes aren't unheard of!  so i need to get those sorted asap.  this bike will be a lot faster than stock, and it would help if it could slow down accordingly.

also on the list:

longer shocks/520 chain and sprockets
HID headlight, and rim to fit bucket/fab or score brackets to mount/tail light
flat tracker bars
assorted buttons and switches for controls (horn and kill push buttons ala old HD mounted to either side of bars, 3-way switch for lights in bucket)

already have magura levers, motion pro throttle, bar-end mirror.

it's going to be  alot more of a street tracker when it's finished.  one of my inspirations is this xs:





more as it happens...

[hoodellyhoo]

Good for you not giving up on this project. That busted frame really sucks. can't wait to see pics of the engine assembly with all those goodies!

[johnspeck]

boretech ignition



dyna mini coils and new wires



all the valve goodies...guides, valves, spring kit





new HD clutch springs



not pictured are all new barnett clutch internals.


here's the rear fender stay off a cb360.  it'll do nicely as a rear hoop for my frame, once the brackets are off.



it'll be mounted at approximately the same angle pictured, hopefully this weekend.

heard back from buchanan's...it would run me $500 to get my wheels laced with their stainless spokes and nipples.  if there are any enterprising expert wheel builders anywhere near austin, get in touch.

in the meantime, cylinder head and all valve stuff are off to the machinist this saturday.  hopefully sunday will be productive (i got called in for work on saturday, but time and a half are fine with me), and i'll have some more progress pics of the frame.