Topic: 1974 CB550 Four Backyard Build (Atl)

[cprice9]

Update:

I wound up going solid state reg/rec from oregon cycles and am running a smaller 8amp AGM battery under the rear section, but will be going kick only.  I also finished up rebuilding  the carbs and found a reasonably priced set of stacks online and am digging the look over the pods.  Lastly, the de rusting method of electrolysis worked like a charm.  My tank had a liner in it but I still got some gunk out, and the gas cap pictures will really show how well this method works.

Baby is in the shop.  Atlas Cycles in Marietta to be more specific.  I went and spoke with Dean a couple of weeks ago and he is a super easy guy to deal with.  I let him know where Id been with this project and what was left so hopefully in the next week or two he will have wrapped up the welding and got her dialed in proper.  Once he is finished I will still have quite a bit to do but I will finally be back on the road.  The last bits I will finish are...

-Polish and brush finish the sheet metal, then clear it.
-build a toolbox under whatever remaining space there is under the rear section
-get the seatpan made and upholstered, brown leather or pleather.  Also going to have a cover made for the stacks.
-get some tank emblems, may have something special done up on a cnc if I can find someone willing
-rearsets

Eventually I will try the 650 cam again, paint the motor, powdercoat the frame, I might cut the front forks down an inch or 3, and depending on how she rides I might have to switch up the suspension, but that will be after I have something else to ride.

If you are around Atlanta i am planning on riding the Distinguished Gentleman's Ride on the 29th, come say hey.  And I am extremely excited to ride and camp out a Barbers in October though I am searching for a camping pass or a spot on the ground in someones site.  Hit me up if you know of anything.

Here are a few pics, i can't wait to get back out.

my new best friend... Dr. back tap


Tank de-rusting via electrolosis


Just the gas cap and the crud that came off of it


Getting carbs together









Getting ready to go to Atlas





Knees in the breeze.

[ajohnson]

Looks beautiful! Great job on it.

[SF]

look great man, congrats. like where you put the plate.

[SOHC4 Cafe Racer Fan]

Great looking tank and seat combo.

[cheftuskey121]

So you're out riding it? Lets see some glamour shots man! You going to ride the Distinguished Gentemans Ride on the 29th? I'll be riding up to ATL for that

[mpower77i]

Love the raw steel tank.  Looking forward to some new pics!

[DustyRags]

Oh man, this is great! I saw the start of this way back when, and just saw the wrap-up after the re-tear-down. Looks fantastic! I did a bare metal tank on my 550 before I sold it last year (had an off-center black stripe) and man, bare metal is the way to go!

Have you cleared it yet? I'd love to see a bare metal tank with red accents. If nobody else does it, I may have to on the next build...

[cprice9]

So as fate would have it her first voyage wasn't for the Gentleman's ride as planned, but I got to take her out for the first time at Barber Vintage Festival... a fitting turn of events so I figured Id share.

Before setting up camp


The first morning around 7:30 am


back home dusty and happy


Barber is simply and overwhelmingly amazing, if you haven't been make a point to go, if you have go again, and if you are going next year I will see you there.

As for the next steps, well I made a list and it is quite long, (you can't be around so many high quality bikes without being inspired to perfect your own... case and point Revival Cycles out of Austin http://revivalcycles.com)

I've got a bit more metal work to do: securing the tank and rear section, refabbing a battery/tool tray underneath, exhaust rear mounting tab, new headlight and mounts, polish/brush/clear the sheet metal, and so as not to sling debris into my stacks I've come up with a screen idea but might have to work around the lack of a cnc.

going to have to retap the head where the exhaust stud stripped out and while Im at it Im going to have to go ahead and powdercoat the pipes:\

electrical is good just need to wrap and hide everything, may add signals.

new parts like rear shocks, rear sets, tank emblems, longer kickstand, ect.

but first a few mechanical bugs to work out after shaking it down.

oil leak from pan
tank liner peeling so I will strip and reline
carbs need tuning
double check valve clearance and timing
retorque everything

So until next update.

PS: These Carpy pipes with stacks and no baffles sound INSANE over 4k

[streak09]

Been keeping an eye on your build, its looking great! I love the flow from the tank to your rear section, looks like its doin the TON just sittin there!

Wish I coulda been there, excellent picture!

[DustyRags]

carbs need tuning

You're running stacks, brother. 

Looks amazing, though! Get those emblems on there!

[calj737]

Caprice - don't powder coat your pipes, have them ceramic coated, inside and out. This will act as a thermal barrier, they won't rust, and they will be much cooler to the touch. Look around for a powder coater that offers that treatment as it should not differ in cost. Just make sure they shoot the insides too, especially near the heads.

Really nice bike!

[cprice9]

Haven't got the carbs right yet, took this after sputtering to a stop.  I can't seem to get on the throttle to quick or I loose control over the throttle, it goes flat in every gear, and begins to sputter until it stops.  Back to the table, but I dug the shot.

Also, ceramic is the intended choice for the pipes... what is a reasonable price range?

[cprice9]

Alright, time for some help from the forum folks.

If you can't tell from the thread this is the setup

1974 cb550
4 into 1 exhaust no baffle
carbs rejetted to 110's and 40's needle clip set at 2nd notch down from top
running stacks


Now that we are on the same page, I am having some issues dialing her in, and as I research and tinker I figured Id reach out for the expert advice of the SOHC4 community.

Here is the issue....

I can kick the bike over fine and she will idle.  After idling for a few minutes the idle speed changes on its own, sometimes higher sometimes slower but I can keep it running.  Once in gear and running, she takes off fine, but after about 2 minutes the throttle response starts to lag.  Low rpm and steady the bike goes fine, but as soon as you try to get on the throttle it lurks, lunges, and sputters.  Lay off and it gets smooth again, but get on it and the sputtering only gets worse.  Once this starts it is only about 1-2 minutes before it is dead, I have to wait a minute, and then we start all over.

I have noticed that  when I take an infared thermometer to the pipes at idle, 1 and 4 are hotter than 2 and 3, 1 being the hottest at around 400 degrees f.

I have already set float height and mixture screws are set 1.25 turns out, I am about to double check my valve spacing though I did this when putting the motor back together initially.  Timing was checked and said to be good by a shop but I haven't checked it yet myself.

So, anyone have experience with a similar setup ever had these throttle sputtering issues?

Thanks for any help.

[calj737]

The guy who powder coated my bike, pipes and such charged me $225 for my 4:1. Glass beaded with 80 grit first, then shot the inside (extra long nozzle) and fully outside. Fantastic work!

You problem sounds like timing. The advancer unit sounds out of whack. I've seen many other posts citing very similar problems and that seems to consistently be the resolution.

[Bankerdanny]

You will need to run a pretty rich mixture with that combo of open 4-1 and stacks. The mixture screw only comes into play at idle and at very low throttle openings, so if you are running well there I would leave that alone.

Have you tried a plug chop? Get on the throttle and when the sputtering starts hit the kill switch, coast to a stop and pull the plugs and check the color.

Personally I would guess that you are lean at the top end and need to drop a groove or two on the needles.

It could also be starving for fuel and you might find that you need to lower the float height just a tad. But I would start with the needles.

[DustyRags]

I'm not genius, but if it's running fine at first and then chokes out, only to restart after sitting a minute or two, I'd guess you might have a fuel flow issue. It runs fine, depletes the fuel in the bowls, and dies. The bowls refill, and it starts up again.

How's your fuel line routing? Gotta restrictive fuel filter in there?

[cprice9]

So, before reading the previous post's advice I went ahead and leaned out the mixture more by raising the clip position to the very top. (in my mind thinking I was flooding the system)  Well it runs now only with the choke 3/4 to fully on and that barely got me home from the shakedown ride.  Now after putting some thought into it, a little more research,  and after reading the last few posts Im thinking it is starving rather than flooding so I am going to pull the clips down one below the center notch to richen up the mix and hopefully will be running a lot better.  For those of you not yet tearing into carbs I found this resource helpful.

http://www.salocal.com/sohc/tech/carb/asmpg_mgs/jetgraph.htm

and another good general theory

http://oldmanhonda.com/MC/Rcarbs.html



Every time I break down it seems to be in a good spot for a pic, I think this bike is vein and #$%*s out for good lighting.  This shot was taken just out front of Brian Fullers Shop in my neighborhood...  an awkward spot for breakdown.

[SOHC4 Cafe Racer Fan]

So, before reading the previous post's advice I went ahead and leaned out the mixture more by raising the clip position to the very top. (in my mind thinking I was flooding the system)  Well it runs now only with the choke 3/4 to fully on and that barely got me home from the shakedown ride.  Now after putting some thought into it, a little more research,  and after reading the last few posts Im thinking it is starving rather than flooding so I am going to pull the clips down one below the center notch to richen up the mix and hopefully will be running a lot better.  For those of you not yet tearing into carbs I found this resource helpful.

http://www.salocal.com/sohc/tech/carb/asmpg_mgs/jetgraph.htm

and another good general theory

http://oldmanhonda.com/MC/Rcarbs.html



Every time I break down it seems to be in a good spot for a pic, I think this bike is vein and #$%*s out for good lighting.  This shot was taken just out front of Brian Fullers Shop in my neighborhood...  an awkward spot for breakdown.

The bike looks great.  I assume you sealed the tail and tank with a coat or two of clear (glossy or satin)?

[Bankerdanny]

The choke restricts air and causes a rich mixture (higher ratio of fuel to air). So if you can't shut off the choke fully after a few minutes of running then you are too lean.

[DustyRags]

Yep, choke = lean.

My thought wasn't rich (too much fuel for the air), but sucking too much fuel out of the bowls (with the appropriate amount of air). Try opening up your fuel flow to the bowls a bit wider was my thought.

[Bankerdanny]

If the problem was not enough fuel in the bowls the choke wouldn't help that.

It would balance the air to fuel a bit, but there would still be a stumble because there still would not be enough fuel to support the RPM levels.

[cprice9]

Alright so now it is worse than ever.

A roadside adjustment to the 2-3 points left the 2-3 point not opening, so I found where 1-4 point was full open turned the crank half a rotation and regapped the 2-3.  Im not sure if thats right and can't find a basic setup guide anywhere, everything is vague when it comes to points.  I also, noticed that the 12v timing light I hooked up stays on for both 1-4 and 2-3 for a small amount of rotation so I twisted my plate to keep that from happening.

As for the carbs... I moved the clips down one position from center.  I kicked it over, took about 5-6 kicks with the choke full on and it reved up super high, ran for a 30-45 seconds and then I caught a funny smell off cylinder 4 and had a bit of smoke come out of the exhaust manifold, then it died.  I since have had a very hard time kicking it over, when I do get it kicked the revs are super high with the choke on, and when I close the choke the rpms drop off quick and the bike dies even with throttle.

At this point Im getting stumped because I think my timing is screwed up, and until I get that I can't see how the carb adjustment is affecting the bike.  Anybody have any tips or resources for a detailed points setup and static timing procedure, Im probably over thinking it at this point but I can't seem to make the vague ass clymers procedure work.  Should my 1-4 point be fully open when it is on the 1-4 F timing mark, and if so how many rotations of the crank should happen until the 2-3 point is fully open, and should it then line up with the 2-3 F timing mark?

Thanks for any help.

[Bankerdanny]

Setting the points gap is less complicated than you are making it. The points cam is clearly visible. center the lobe on the plastic tab for the 1-4 points and check the gap, adjust as necessary. Rotate the engine until a lobe is centered on the gap for the 2-3 point, measure and adjust as necessary.

Once the gaps are set THEN move on to timing.

[cprice9]

Thanks for the good words bankerdanny.  So gaps are set, valves are set, timing is set... the test ride went better but Im back to carbs.

The Shakedown:

So after getting everything as close as I could I put the choke on kicked her over and again got a supper high rev, pulled the choke off and rolled it into the back yard.  There I set the idle screw to around 1500 rpm and began to check the temps of the exhaust manifold.  Cylinder 1 is running in the low mid 200s F and 2, 3, 4 are over 300 F.  The bike was idling just fine but after about 2 1 minute the idle shot up to close to 3000 rpm by itself and stayed there.  I readjusted the idle screw and headed out.

Bike is running better than it has so far so I feel like Im getting close, and a proper strobe timing and vacuum carb sync will do well for this bike.  However after about 3-4 minutes of cruising the neighborhood after a stop sign the sputter returned.  1st gear up to about half throttle it just started sputtering, into second and full twist of the throttle and it seemed to pick back up, through the rest of the gears sputter in low throttle but 3/4 to full throttle running fine until the next stop sign where it died.  Choke back on, kicked over, choke off and she ran fine again for another 3 minutes and then the same scenario in the same part of the loop I was running. 

I could enrich the mix one more notch down but then Im out of notches, should I be messing with the mixture screws at this point, they are all 1 an 1/2 turns out.  Seems like maybe a pilot jet but it is idling fine (with exception of random spikes in idle rpm level)

[PostScript]

Digging this thread back from the grave. I picked up this CB from "cprice9" earlier this year and figured I would continue to document the build here (hope you don't mind Chris). This is one of many projects I have going so the updates might be slow.

The night I picked it up, I had told Chris I was going to swap to more modern suspension, brakes, etc. but I really fell in love with where he was headed design-wise after getting it home. First order of business was to change the riding position. I'm over 6' and the stock controls were awkward to say the least. I came across CognitoMoto and picked up a few house pieces (linkage, brackets, and shift arm) and some Tarozzi rear sets:



Parts were super easy to install and only required some linkage work. The rear brake linkage (not pictured) was a little bit of a chore and I still need to install a clean brake switch. You can also see the beginning progress of the tail section. After watching Dustin Kott build his style seats and tail online, I decided to go with a similar design and use round rod to form a skeleton:





Fast forward a few weeks and the tail is almost complete metal-wise. I  fabricated a small electronics tray to sit in the cavity under the seat/tank and houses a small fuse box, rectifier-regulator, and the new Antigravity 4-cell lithium battery. It sits flush with the frame tubes so it is almost invisible when viewed from the sides. The new tail is much shorter than the one Chris had built originally and no longer houses the battery above the rear tire. It is kicked up more and follows the tire shape when viewed from the rear. All edges are finished with round stock. The rear frame was shortened to accommodate the new seat dimensions. I also added a small raised stripe to flow with the CB750 tank. Now I just need to cap the open rails, I just cannot come up with a design I like:





In those pictures I was experimenting with lowering the front forks another 2in. I'm liking the look and might finalize the length and loose the goofy horns protruding from the triple tree. Before everyone goes nuts about geometry, this is more rolling art than a purpose built mountain carver. Looks>performance as far as I am concerned as I do not plan to ride hard.

Throughout the process, I've been pulling aluminum parts and sanding/polishing. I would say I'm about 70% done now.

That's all for now. Comments? Suggestions? Next on the list will be front-end modifications, finding a suitable tail light, tag bracket, body and paint (have to choose a color), and seat upholstery.