Topic: Oil leak and other newbie questions

[WWrides]

So, I'm a new rider and recently purchased a beautiful, DIY-serviced 1973 Honda CB350F. It seems to be slowly leaking oil, but I can figure out exactly where. I tried to remove the cover on the left side of the motorcycle because I could see some wire covers were coated in oil and wanted to investigate further, but I ended up stripping one of the screws because it was on so tight.  Any suggestions how to get the screw out now that it's stripped?

Also there are some things on the bike that I'm unsure if they're working properly or what they're for (hoping to find a good honest mechanic soon that can help me out, but in the meantime, I'm asking here).

Pic 1 - wet cables
Pic 2 & 3 - cover that I can't remove. To clarify, I removed the name plate cover, but not the actual cover. The outer screws, one specifically, wouldn't budge and ended up stripped.
Pic 4 - fuel filter - was not full of fuel the first few days, but now it is. Is there supposed to be some space in there?
Pic 5 & 6 - rubber tubes hanging out in front of my back tire. I can't tell where they come from, or what they do.

Sorry if these are dumb questions. Like I said, I'm totally new to motorcycles.

[Kaze]

Since you said that your'e new, one thing I will suggest right off the bat is to get yourself some JIS (Japanese standard) screwdrivers (off Amazon). Even though the cross-point heads look like Phillips, they aren't. It's totally a trap. You'll save yourself some headache by using Japanese standard.

For stubborn JIS head bolts, a set of JIS tip impact driver heads and a cheap impact driver (also Amazon) are pretty much necessary tools for these old dears.

[Mark1976]

   My first question, how many miles are on the bike?
   A impact driver and bits is a great investment with these bikes, if that doesn't work just take a drill bit slightly larger the the screw head and drill the head off. Then remove the protruding shank with a pair of vise grips after you've pulled the stator off.
   Then get the appropriate fuel line to replace the clear (and wrong) line that's currently on there and if you have to or must keep the filter, get a smaller one and relocate it.  If I were you I'd examine the tank and petcock,  if both are clean, dump the filter altogether .
  So, while your at it, put on some road tires, that way you'll be able to reinstall a front fender which will go a long way toward improving the handling.
  Otherwise, it appears you have a decent ride. The oil leak, well it's an old bike, it happens. Once you have the stator off you'll be able to determine if that's where your leak is coming from.  I believe there's an oil passage plug in there that may be your issue.
  Keep us informed...

[calj737]

Unless I’m mistaken, the rubber tubes in front of your rear tire are overflow lines from your carbs. They should trace back to the bottom of the carb bowl.

Ditto on the JIS screwdrivers. Every screw on your bike is JIS and every bolt, nut and fastener is metric. Don’t make any mistakes on that.

[carnivorous chicken]

+2 on the JIS and impact driver. I fyou go to a hardware store tell them it's teh type you hit with a hammer. Somewhere between $10 and $20.

The rubber tubes in front of the back tire are the overflows for the four carbs. They attach at the bottom of the float bowl on a nipple.

For the oil leak, if it's a little seeping from under the stator cover but not enough to leave a drip I wouldn't worry about it, but keep an eye on it. There is a rubber seal that goes around the cables. If it is bad you could try a little sealer on there, or pull it off and replace it with the gasket.

IF there is a drip it's might also be under the cover just behind the stator cover. To get to it, you'll need to remove the pegs and the shifter, then it will pull right off (with a little effort). Under there you've got your starter, oil pump, and oil pressure switch. Most likely culprit (and easiest to fix) is a leak with the oil pressure sending unit. If you clean the whole area up and run the bike, you can tell where the leak is coming from. The oil pump has a few o-rings and they can develop leaks. The starter has one o-ring (IIRC) that can leak as well. Another potential culprit could be the shifter lever seal.

It would be worth replacing the fuel line with 5.5mm. I run a fuel filter but much smaller, although as some are against them. I've never had an issue though.

These are great bikes, especially when they are dialed in and purring. Get a manual, and make sure to learn the 300-mile tune-up procedure. You should do that right away, actually, if you don't know when it was last done. Plugs, points, valves, oil and filter change, timing, etc.

[HondaMan]

There's 3 ways to [now] remove that offending screw:
1. The impact driver, mentioned above. Ace Hardware sells a decent one. Use a hammer, not a little one, with it.
2. Vice-grip pliers, which can just barely reach that screw. Done it before.
3. A 1/4" drill bit. Drill into the center of the crosspoint, then keep going until the screw head falls off. The shaft can be removed after the others, and the cover, are off.

 These screws have been in place 50 years now, so they are a little crusty inside, which you'll see when you get them out. Add a drop of oil to each one during reassembly.

[bryanj]

It would be unusual for a leak inside that cover, the cables could be oily because they are the lowest point.
DO NOT turn the engine over with the generator cover off as there is an oil gallery plug that will blow out and disappear! Technicaly there is no oil in there on a 550 but there is a crankshaft oil seal which is a major job to replace and an O ring on the mentioned plug which is easy to replace but an odd size and rarely leak

[calj737]

It would be unusual for a leak inside that cover, the cables could be oily because they are the lowest point.
DO NOT turn the engine over with the generator cover off as there is an oil gallery plug that will blow out and disappear! Technicaly there is no oil in there on a 550 but there is a crankshaft oil seal which is a major job to replace and an O ring on the mentioned plug which is easy to replace but an odd size and rarely leak

It’s a 350, not a 550.

[flybackwards]

Congratulations on your "new" bike and a great choice for a new rider - you will learn so much. CB 350 was my second bike. The people on this forum are very experienced and knowledgable and very helpful. Good advice on the tools. If I might suggest that if you have the coin check out Vessel Tools for your jis screwdrivers and impact driver - good tools make the job so much more pleasant.

[WWrides]

Thank you! I had no idea about the JIS screwdrivers. I was wondering why none of my Philips were working! I will get those soon.Im hoping to visit a suggested mechanic today or tomorrow that might help me out, too. I really appreciate all of your advice. I wish this was the only thing I had to focus on, then I could learn as quickly as I want!

I am planning on replacing the tires and putting the fender back on. I’ll have to get someone to look at the fuel line. The previous owner put that on, but I don’t remember why.And I pretty sure the tubes aren’t the overflow since they’re not connected to the carbs. They look like they go up towards the air intake vent.

[Kelly E]

Get yourself a set of left handed drill bits. Put the drill in reverse and use a 1/4" bit. Most of the time the screw will start coming out just before the head pops off. Recently on the 78' KL 250 I removed 29 seized screws with the left handed drill bits and every one of them came out.
I also recommend Vessel Impacta JIS screwdrivers, the impact function is built into the handle.

[carnivorous chicken]

And I pretty sure the tubes aren’t the overflow since they’re not connected to the carbs. They look like they go up towards the air intake vent.

If there are four of them, they're the overflows and simply aren't attached to the bottom of the carbs. There is also one tube, usually clear, that vents the battery and allows for any drip to fall to the ground instead of on the exhaust. And there might be two that vent the carbs. Gotta be one (or more) of those three -- or the vent hose for the crankcase breather!

[WWrides]

I'm trying to find the double-ended bolt pictured to attach my other mirror (evidently the previous owner misplaced it). Is that an impossibility? The way mirror hole is cut is slightly smaller than the bottom thread, so I can't just find that size bolt to fit through it. Should I just get new mirrors?

[calj737]

Typically, the handlebar perch is tapped for a bolt. It should be 10mm 1.0 pitch if memory serves. Your existing mirror may want to mount to a stud instead, but you could simply get a longer bolt that passes thru the mirror yet still threads into the perch.

I’d have to see the size differences of what you have and what you need to make a final recommendation. But maybe that will help.

[WWrides]

@calj737, I may not have explained properly (or it's possible I didn't understand what you said). Here are some more pics to explain:

Pic 1 - bottom of mirror stem (I'm holding it upside down) with the existing bolt going through. The red highlighted part is not threaded.
Pic 2 - the bolt pushed all the way through. The red part is showing you what is inside of the mirror stem. a washer and nut fit inside the mirror stem to hold it in place and the bottom of the bolt (which is the top in this picture) fits into the handlebar.
Pic 3 - turned the bolt around to show that I wouldn't be able to fit the proper size bolt through the mirror stem

Hopefully that helps. Sorry if I misunderstood what you were saying.

[bryanj]

350, 400, 500, 550 are all same under generator cover