1970 CB350

2009-01-15T19:28:00.000-08:00

Clutch Cable Replacement

2007-09-08T14:46:00.001-07:00

Snapped the clutch cable at the handlebar, luckily I wasn't too far from home. To get her out of gear and into neutral so I could walk her back, I rocked her back and forth a bit while pushing on the shifter with my hand.

The new cable from O'Hanlon's Motorcycles was about $19. The Powerbuilt impact driver was $15 from Kragen. All the forum posts were right, don't try to do this without an impact driver. The four screws holding the countershaft sprocket cover will not come off without one. I'm going to replace them with hex screws as soon as possible.

Now that I've replaced the cable she seems to shift better than ever. This could just be because I did a better job with the adjustment this time, or because there is less grease and gunk inside, but for $35 and a couple hours, it's worth attempting before major clutch work.

Note: Leave the old clutch cable in place as a guide until you've routed the new one.

Remove Old Clutch Cable

The impact driver. If it doesn't seem to work at first, make sure you've got it set to loosen, not tighten. I thought I'd followed the simple directions well enough, but I had it set wrong at first.

What we're dealing with. You can see three of the screws that require the impact wrench, the other is hidden by the shifter.

Remove the foot peg. Take note of the order of the five pieces.

Remove the nut holding the rear of the shifting arm.

Remove the bolt holding the front of the shifter, where it attaches to the clutch. Take note of the angle of the clamp that the bolt cinches. When I put the shifter back on I couldn't shift above neutral because I had the angle wrong.

First of the four screws that are loosened with the impact driver. They're different lengths, so pay attention to which goes where.

Second.

Third.

Fourth. Nevermind the shift lever, I went out of sequence.

The innards once you get the screws off and turn the plate around. It's nice to finally see what I've been dealing with when doing clutch adjustments. From this point on I'd suggest wearing gloves, there is a lot of thick grease around the ball bearings.

I ended up having to cut the end off of the clutch cable to get it backed out through the plate. The metal bulb at the end refused to come out of its slot. I also ended up unhooking the spring to get a better angle.

Plate and arm. You can see the unhooked spring and the metal bulb from the end of the clutch cable still in the arm.

New Hotness

The new cable.

Routing it under the tank alongside the old one.

Inserting it through the handlebar adjuster.

Slotting it into the handle.

Take off the rubber grommet to get the new cable into the plate.

In the plate, grommet back on.

Hooked the new cable back into the arm, then reattached the return spring.

From left: plate screws, shifter and its bolt, foot peg bits.

Plate back on, ready for the screws.

Put the shifter back on. Adjust the angle of the shifter so that it will shift through all the gears. Another way to say that would be that the clamp that I'm about to bolt together in this photo can be rotated clockwise to make it easier to shift up, and counter to shift down.

Nut on the rear pivot point of the shifter.

Another view of the order of the foot peg pieces. After putting the foot peg back on do a clutch adjustment and yr done. I'll take some photos of the adjustment next time I do one.

Idle Problem

2007-05-29T14:49:00.000-07:00

Damn. She was running so well yesterday, but today she's gone bonkers. As soon as I started her up she had trouble idling. Figured she'd be a little better once she warmed up, but no such luck. Spent fifteen minutes in a deli parking lot messing with the idle and mixture screws to no avail. She would either die or jump up to 2,000 or 3,000 rpm on her own. The random jumps and drops in idle made me think air leak, but I also noticed the blinkers weren't blinking correctly. They were blinking irregularly and too fast, even though all the bulbs were working. So maybe it's electrical?

I'm going to go spray some WD-40 around looking for an air leak, and then poke around with the multi-meter. I feel sorry for Dave's neighbors who are going to have to listen to my bike some more.

Update

Well, it seems to be a leak in the boot between the left carb and the head intake. If I pull on just the left throttle it doesn't increase the RPMs, it just makes a loud thwup-thwup-thwup. After I let go of the throttle the RPMs increase slightly for a few seconds. While it doesn't backfire, I'm assuming that the thwup-thwup-thwuping is the mixture too rich, and the momentary increase in RPMs is the mixture passing through a proper ratio of air to fuel on its way back down to being too lean due to the air leak.

Spraying DW-40 on the boot doesn't do anything at first, but after ten or fifteen seconds the RPMs shoot up. It took a few tries for me to put two and two together, as I expected the DW-40 to act more quickly.

I wonder how this happened between yesterday and today. The only things I can think of are that the plastic cover was pressing on the carb and putting pressure on the boot. Or maybe I tightened the hose clamp too far. Now to find out how much a new boot is, and if there's a temporary fix that'll get me back to SF.

Re-Update

Rode over to Auto Zone to get some liquid gasket to see about sealing up possible air leaks. Also picked up some fuel line to replace the old ones as they've started to leak. She had problems accelerating/maintaining speed the whole way over. Came out of Auto Zone to find fuel leaking from the left air filter. That about drove me bonkers, but then I realized that the overflow hose passed above the air filter, so it wasn't that the overflow was clogged. Hammered on the bowl to loosen the float and rode to get a bite to eat. After eating I came out to find that she was running well again.

I'm not so sure that the problem was an air leak any more. Maybe it was that she was running too rich. Still not sure why she would just start running well again. Gonna see how she's doing tomorrow. I'm actually hoping the problem comes back. I'd like to get to the bottom of it rather than just be glad it disappeared randomly.

Carb Rebuild

2007-05-27T20:13:00.000-07:00

Picked up two carb kits for $25 each, and the correct main jets for another $6 each, for a total of $31 per carb. Now, instead of topping out at fifty-five, I'm shifting into fifth at fifty. She makes sixty at just about 5900 rpm, seventy at about 7k. Acceleration is better too. Hot damn.

Right Carb

The rebuild kit for one carb. Had to buy a separate main jet as the one in the kit was 115, and I needed 105. Not that I would've known that, but Charlie hooked me up.

Disconnect the air filter, throttle cable, and choke linkage. Remove the carb, stuff a shop towel in the intake to keep anything from getting in.

Removing the diaphragm/slide assembly (after removing the top cover and diaphragm return spring).

Removing the float bowl.

A view of the float bowl, floats, jets.

Removing the primary and secondary main jets and the holder. Just pull on them with your fingers.

Main jet holder, needle jet, primary and secondary main jets. To remove the main jet holder and the needle jet which are under the primary and secondary main jets, you reach down through where the diaphragm/slide assembly was and press them out with your finger or a toothpick.

After removing the above.

Pressing the float assembly pivot pin out with a toothpick.

Removing the float needle.

Unscrewing the float valve seat retainer clip.

Not shown: remove the float valve seat by grabbing it with needle nose pliers. I used a shop towel to protect it from the pliers. Then remove the 'pilot jet' which turned out to be just a little rubber plug. Under that was the slow jet which just unscrews. I don't know why Clymer's says to push out those two, because there's no pushing involved. Also remove the idle mixture screw and spring, and the float bowl drain plug. Then use a pair of needle nose pliers to reach down inside the diaphragm/slide assembly and compress the retaining clip. Just grab one side and pull in inwards instead of trying to grab both at once. Remove the clip, the little plastic piece, and the jet needle. Hit everything with carb cleaner and compressed air. Make sure to spray through all the little holes and passageways in the jets and carb body. Carb cleaner is nasty stuff, so if you don't have goggles use the safety squint.

Cleaned up, in the process of being reassembled.

Measuring the float height.

Pilot jet.

From top left: needle jet retaining clip, a silver thing and washer that I didn't end up using, main jet holder, primary main jet, o-ring, needle jet, secondary main jet.

The jets before pushing them in.

The hard part is over.

Jet needle retaining clip after bending it to match the old one below it, plastic thingy, jet needle.

Reassembled diaphragm/slide assembly.

View inside the diaphragm/assembly. You can see the plastic thingy and retaining clip.

Float bowl and new gasket. Didn't bother with sealer.

Putting the diaphragm return spring in after putting in the diaphragm/slide assembly.

Nice clean carb back on the bike. It did leak gas through the overflow at first, but hammering on the float bowl with a screwdriver managed to unstick the float.

Left Carb

A view inside of the main jet holder and the needle jet poking up. They're to the left of the butterfly valve in this shot.

Inside the float bowl. Note which side/hole of the primary and secondary main jets is facing out.

Cleaned and reassembled.

Spark Plugs

2007-05-27T18:53:00.001-07:00

Some shots of the old plugs. I replaced the left one, but had to reuse the right one.

Left plug.

Right plug with insert.

Left plug on top, right plug with insert on bottom.

Right plug on the right.

The kit I bought to get a new insert, but the threads are different I think. The old plug is back in for the time being.

Spark Plug Issues

2007-05-25T23:23:00.000-07:00

Oil change went fine. Left plug went fine. Right plug came out with a thread adapter. Turns out someone had to tap it. The new aluminum adapters I got don't quite fit, so the old plug is back in and she starts fine.

Tomorrow I'll try to figure out what to do about the right plug while I work on the carbs. I knew it couldn't be easy, but sheesh.

15,350 Trip Report

2007-05-25T13:37:00.000-07:00

Rode up across chrysopylae yesterday, heading up the 101. The uphill grade and headwinds brought my speed down to 45mph and I seriously doubted whether or not I could make it to Sonoma County. But in the end, she was the blue engine that could.

Rush-hour traffic allowed us to proceed at a more leisurely pace, and when the traffic thinned out I took to the back roads. Heading west on Lucas Valley road I was treated to more than ten miles of s-curves through cool redwood forests. Once I got out to the Nicasio Reservoir it opened up and I let her rip. She made sixty-five, but that seemed to be pushing it.

Symptoms

It seems that my carb adjustment to make the mixture richer had the desired effect. Even after prolonged periods at high speed she still accelerates through first and second just fine. Her idle speed does drop down to below 1k rpm though. If I'm coming up to a stop sign from a speed over 50mph, and I pull in the clutch and let her idle, she will die. Happened out at the reservoir yesterday, and again today on the way up to Santa Rosa. While that seems to make some sort of sense in my mind, I can't put my finger on why. Hopefully this carb rebuild will help.

To do today:

Oil change
Clutch cable adjustment
Brake cable adjustment
Carb rebuild
Plugs

Not sure in what order those will go. We'll see. Talking to Charlie yesterday while picking up the carb kits, he mentioned I should do my timing as well. So it looks like I'll be fucking with points and valves also.

Wish me luck. Hopefully she runs better and not worse after all this.

Oil Change Prep Work

2007-05-23T18:40:00.000-07:00

Stopped by Charlie's to see about getting the o-ring and gasket that Clymer's says I need to replace when I clean out the oil filter as part of the oil change. He told me that I don't need them, as they only clean that out when a bike is in for major service. Seemed strange to me, but he knows better than I. Still plan on posting that to a forum or two and seeing if anyone agrees with it.

His oil recommendation boiled down to Castrol GTX (non-synth) 20-50. He said they use something that sounded like Spectre, but I can't remember the exact name. But for half the price he said Castrol would be fine.

I asked about checking the oil level, and he said that it should be done on the center stand (solves that question), with the dipstick unscrewed (Clymer's says the same thing), and the engine cold. She's outside cooling off on her center stand right now. This was my first time putting her up on the stand since I bought her. Not easy.

I also asked him about carb kits, which they do sell for $25, same as on eBay. But he said their kits had the wrong main jet, and that would be another $6, for $31 total per carb. A reasonable price to get it same-day from someone I trust. Going to read through the process again tonight and decide whether or not I'm going to do the carbs up in Santa Rosa this weekend. They need to get done, and it is a three day weekend, so I'll probably end up doing it.

Also possible candidates for the weekend: check/replace plugs, adjust brake cables, learn to adjust shocks for two people.

I asked Charlie about the missing after a long ride, but he said there were too many variables to figure that out without looking at the bike. Totally understandable, as he is running a business. I asked him how much it would cost to have them go through the bike, to which he replied approx. 2.5 hours at $75. Sounds reasonable, but I don't plan on it.

15,243 License to Ill

2007-05-21T23:42:00.000-07:00

Passed the driving portion of the M1 test today. It was markedly easier than I remember it being when I practiced a few weeks ago. I suppose I've gotten to be a better rider.

Took her over to Berkeley to try out consistent freeway speeds, which lead to a problem I had the other day after a ride down the coast to Daly City.

Symptoms

After a twenty minute ride at or above forty-five mph or so, she has problems accelerating through first and second. There is rapid surging, what sounds to be missing/backfires (but not very loud), and a complete inability to accelerate quickly. If I push through and make it to third she seems to run better. Sitting parked for thirty minutes is not enough time to solve this.
Also under the same conditions, she absolutely refuses to acknowledge she has a first gear if I don't get her there before the stop. This leads to lugging her from the stop in second.
Something was squeaking/rubbing with an extra person on the back.
After hitting the kill switch and coasting into my parking spot (woke some baby last week while parking) I could hear something rubbing against the back wheel.

Solutions?

I'm hoping the upcoming carb overhaul will help with the missing. Maybe it is a mixture issue? Is she colder or hotter than normal city driving after a long run at high speed? Compression?
Oil change in the short run, clutch overhaul in the medium run.
Shocks.
Going to track the rubbing down tomorrow by coasting down hills with the engine off. The wheel probably needs to be replaced anyways due to a largish flat spot on one side of the rim. Spokes shot to hell. [update: drum brake?]

Planned

In the next day or two I'm going to head by Charlie's to pick up a gasket for the oil change and to get his recommendation for oil type. Hopefully he'll also have that front brake light activation switch I'm looking for.
After the oil change, in some sort of order:

Carb overhaul
Points
Brakes
Clutch overhaul

Clutch Adjustment Woes

2007-05-04T21:20:00.000-07:00

Got stuck at Trader Joe's earlier, the kickstarter wouldn't budge. Got it loose by putting her in first, getting to a running start and letting the clutch out. That seemed to shake whatever it was loose.

Got her home and have been fiddling with the clutch cable. I can eliminate the clunk into first at a standstill, but then the clutch seems to slip under load. Eliminate the slip, and the clunk is back. Frustrating, but at least it fits with my understanding of clutch function. Too much slack in the cable leads to too much pressure from the springs and the clutch plates don't disengage without coaxing from the engine: clunk. Cable too tight, not enough pressure on plates: slip. I think I'll take the clunk for now because I can minimize it through conscious effort.

At one point I had the clutch cable way overtightened, and I thought that I snapped it as it suddenly went slack. But somehow it came back, not sure what happened. I think that I'd have better luck if I had more of an idea of what the screw on the outside of the case is doing with the clutch. I understand the cable, but not the screw. I have the feeling that once I do I'll probably deviate from the recommended "one quarter turn out from when it meets resistance."

Forum Posts That Provide Insight

2007-05-04T14:48:00.001-07:00

1

It sounds like you're pushing out the cam past it's range. It's happened to me before but luckily it's always popped back into position. I'll try to explain this. First loosen off the clutch cable completely at the lever and at the sprocket cover. Now you need to set the clutch rod free play. See the hex nut on the sprocket cover and the slotted bolt that it's holding? Hold the bolt and loosen the hex nut. I can't quite remember which way to turn but try both directions. What you're looking for is tightening to the point that the cam ball bearing touches the clutch rod. You can feel it touching each other when it's at the right point. Then back it off about 1/8 turn. Now the clutch rod will guarantee that the clutch springs are fully engaged when you release the lever. Now connect the cable to the clutch lever. Set the cable adjuster by turning the threaded disc all the way against the cable stop. Now begin tightening the adjuster on the sprocket cover by increasing the length between the 2 hex nuts on the cable. Do this until the lever has almost no play. Tighten the nuts against each other to set the cable length. You can fine adjust the cable at the lever by turning the disc away from the stop but always leave a slight amount of looseness to make sure the clutch is completely engaged when you release the lever.

2

things to check: make sure the shifter pedal is not loose (inspect it when the bike is parked). Wiggle it around - are any bolts loose? I had this problem on a honda when some of the bolts for the bracket holding it had worked a bit loose.... was hard to get into first and second.

when moving - check your technique for shifting.... where is your foot when you are ready to go from first to second? On harder shift bikes, I find it easier to "stage" my foot - like from first to second, get the foot under the shifter - put a slight upward pressure on it (you can actually put a bit of pressure on it)- pull the clutch, at the same time increasing pressure upward. Think of "pressing" the shifter up until it clicks.... like lifting a heavy weight upward in a smooth motion with your toe....don't try to "bump" it upward - sharp, short "kicks" to shift can lead to inconsistent engagement if you don't get the lever all the way up.... especially that 1-2 shift...)

The other thing this does, is because you are shifting as you are releasing the clutch - your foot is in place, the shift starts sooner, and will occur as the throttle is released.... and not - pull clutch, wait for RPM to drop all the way down, then try to shift.

in effect, you would be shifting closer to where the engine speed matches the driveline / road speed for that next gear..... if you are higher in the RPM as you shift from one gear to another - letting the engine drop too low in RPM is harder because the gears in the transmission are moving at different rates....

sloppy shifting technique was why my magna would sometimes pop out of second as well - it wasn't fully engaged, and it's a slightly different travel than the other shifts.

Fuck

2007-05-04T13:34:00.000-07:00

Went to start it this morning, had some problems. It wouldn't start after a couple kicks, so I shifted out of neutral to double check that...I don't remember. Anyways, I got it started, but then when I tried to put it in gear it died like the clutch wasn't working. Then I couldn't get it back into neutral...trying to kickstart it would move the bike forward. I figured that somehow the clutch cable must've loosened up, tightened it at the hand lever and was then able to get it into neutral and started. After work I'll have to go through the cable adjustment again.

Hard Shifting

2007-05-03T15:15:00.000-07:00

Things to know/changes to try:

maybe hondas just shift hard
oil change
shift pedal loose?
RPMs too high
clutch cable adjustment (followed procedure in clymer, no real change)

wait, that s not right...from this posting: "The kick starter should turn the engine over without slipping, the clutch should work smoothly with the engine running." She actually kicked over more easily after the adjustment.

goober350 seems to be having the same problem i am...too bad that forum is fucked up and won't let me register.

interesting/helpful links to refer back to:
ElectroKen CB350 posts
MSN Group
hondabikes.net post

test

2007-05-03T15:05:00.001-07:00

wow. look at this, i remember this blogger interface.