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Ok, so I've got this new to me 71 CB350. A quick run down on what' been going on. I had one cylinder quit working, but was able to redo the points wires and got them both firing again. The left carb runs great, from giving it a little throttle all the way to full throttle. However, the right side carb bogs down when you first give it gas and then seems to level out at higher rpms. I'm not a carb guy, so maybe it's something simple. I don't want to start replacing parts for no reason. Thanks
I'm wondering if it's still an ignition problem or a carb problem?
Is there supposed to be lag in the right carb on these? It seems like my left carb (as sitting on bike) is has a 1/16" more tension than the right cable. If I try to lift the idle arm on the right carb it does not react immediate and only goes up to maybe 3k RPM max, but if I raise the left carb idle arm just enough to raise the rpm then I move the the right it goes way up in RPMs. I also noticed that the left carb seems dialed in very good, plug color looks great, but the right side mixture screw is almost all the way in and is still running rich. Like I said before, the right side exhaust, the one that is running weakest has the most exhaust pressure, and seems to be running hotter than the left side. I'm sure this is something minor, but I am puzzled. I've torn the carb down as well and all jets are free and clear. I set the float to 25mm roughly. It might be too much?
Hmmm.... I tore that carb apart twice, soaked it, and sprayed carb cleaner through all the jets. I don't know what else to do. I will probably end up changing the carbs in the future anyway, just driving me crazy not being able to locate this issue.
I honestly think it has something to do with the coil, or spark. Initially it was the left side that was acting up with the same issues, now it's the right side. I have verified it has spark, but I can't tell if it's full power.
Is there supposed to be lag in the right carb on these? It seems like my left carb (as sitting on bike) is has a 1/16" more tension than the right cable. If I try to lift the idle arm on the right carb it does not react immediate and only goes up to maybe 3k RPM max, but if I raise the left carb idle arm just enough to raise the rpm then I move the the right it goes way up in RPMs.
Lemme just take on this part of you problem (acknowledging that there might be other issues at play here...).
For a CB350, you've got one throttle cable at the housing/handlebar, but it splits into two cables and each mounts on the inside section of your carbs. The cables can be adjusted individually here -- i.e., where they mount to the carb. You'll notice a threaded end of the cable, and a nut on the threaded end (to lock them). You can do this visually: are the two threaded ends in/out about the same length? Does it look like the RHS cable isn't responding as quickly as the LHS cable, and therefore you should use the threaded ends to take up the slack? Did the nut for securing the correct slack come loose, allowing the cable to develop slack?
@ carnivorous chicken: The right side cable has a tiny bit of slack, but when I move the arm with the idle arm on the right side with my hand, not using the handlebar throttle it bogs. I think even if I get both carbs on line identically it will still have the issue.
@Sonreir: I will let it sit for the weekend as I'm going to be out of town. When I get back I will check it and see where it is at. I drove it today with the headlight on for 15 mins and it was about 12.55 volts. I'll let you know what I find out come Monday.
I will also look into the timing, but I don't understand why it would be off. It was very weird....everything ran great. I drove it an hour home. Went into a light rain and had to push the bike home. Found out that the left side wasn't firing correctly, swapped the plugs from left to right and the problem followed the plug. I went and got new plugs, still an issue. Re-soldered the points wire ends and clipped off some parts on the end where the insulation fo the wire was cracked. Maybe it's still an issue with the points or contacts?
I'll let you know what I find out about the timing if I have time to check it this week.
You know what I just realized... Previous owner had new points, plug wires, and had carb sync'd. I have the receipts (obviously didn't have any mechanical skills and paid some one $700 for basic stuff). I think there was an underlying issue and they threw a ton of money to fix it, still didn't do right so they sold it. Good for me, bad for them.
I'm about to head out for the weekend. I'm letting it sit as Sonreir suggested to do my volt test later.
Quick question, When I pull the plug wire off (when running) I get a shock in my hand, but it's not painful or even surprising. Should it be a strong bite? I couldn't find the spark tester I wanted, but I can see the plugs arching.
Yup battery is no good. I purchased a new one today, but since I am leaving the country for while I won't put it in until I return. I'll post in a couple of months if this fixed it. Thanks everyone.
Yup battery is no good. I purchased a new one today, but since I am leaving the country for while I won't put it in until I return. I'll post in a couple of months if this fixed it. Thanks everyone.
If you want to determine if its the coil or spark plug wire you can try swapping them to see if the problem follows the move. Its a nice easy and free test.
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