[Armitage]

Hi,

Just recently put my CB350 K1 together for the first time. When I bought it it was all tore down and delivered in boxes, so I've never started it before. Hasn't been running since the 80's is my guess. Total restoration has been done, every single part and screw in the engine has been inspected and cleaned or exchanged. First start-up ever this weekend! And it started easily, what a relief! All good to that point.

I had the oil inspection screw (in the top, left side) out to see if the oil was coming up, but so far nothing! I've had the bike running for a few minutes up till about 3,5k rpm, and even a short ride around the block. Nothing comes out. Is that the wrong way of doing it, should I leave to bolt in when riding and then afterwards remove it (while running the engine) to allow pressure to build up? Or will it work either how?

When I first realized that this might be a problem, I poured some oil into the top end through the valve adjusting holes to be sure to have at least some lubrication in there. I hope this helps through this testing period..

- I have tested to kick the engine over with the right side oil filter cover off. Oil is pumping out of the lower hole. If I put my thumb over it when kicking, it easily moves my thumb out of its way, so I assume the pump isn't all done at least.

- I have blown compressed air through the upper hole at the oil filter, and seen that if I put a dab of oil in the inspection hole in the top, the compressed air will blow it away. So it seems like the oil passage(s) up to the top isn't clogged (at least not fully).

But there is one thing that makes me wonder. The upper hole at the oil filter is all dry. Of course the oil will fall back into the oil filter (or wherever it goes), but shouldn't there at least some residue of oil in this hole when I open it up? Could there be some problem with the oil filter cover? It seems fine to me, the spring is in good condition and the parts move freely. Or why wouldn't the oil leave the oil filter and travel up the engine?

Thank you for your thoughts in this,
Tobias

 

[doode]

The hole that you're blowing air through, by the oil filter/slinger... The cap with 3 screws have 2 holes in it. Are they lined up correctly with the crank case cover? If it's not installed with the holes lined up then you will have an oiling issue.
Is there any oil in your slinger?
It may be worth checking to make sure your oil pump is correctly installed and functioning.
But start with the oil slinger cap(3 screws) and check if oil is getting to the slinger.

Also, in the cap there's a little spring loaded piece. Is that working/springy?

 

[Armitage]

Thanks for your reply doode,

Yes, holes are lines up correctly!
Yes, there's oil in the slinger!

A function test of the oil pump is on the list if nothing else helps. But as I mentioned - oil comes pumping through the lower hole when I kick the engine over.

Yes, the little spring loaded piece is in place and seems to function, it moves freely and the spring is in good order. The tip of the cover with the hole in it that delivers the oil into the filter/slinger is a bit nagged in the end of it - can this have any effect on anything?

I came to think of one thing that might help me with this puzzle. I assume that the left side of the engine (where the alternator/stator is) gets oil from the same passage in the upper crank case - is that correct? Since I have oil on the left side (I know this because I had a oil leak at the cover of the alternator/stator) can I assume that it has been transported there by the oil pump?

 

[doode]

The u shaped part by #10?

https://www.cmsnl.com/honda-cb350k4-super-sport-1972-usa_model433/partslist/E17.html#results

 

[doode]

Sorry, I reread your original post again and realized I missed a bunch of stuff.
Well, it would seem like you are getting oil as it would've seized by now if not? And all your testing sounds like there are no blocks and the pump is working.
At risk of causing damage, try drying the inspection bolt and hole. Insert the bolt and remove. Once no oil residue comes off, try start up and let it idle a minute. Remove the bolt while bike is idling. Is it wet or dry? That's what I'd try if it was my bike...

 

[Armitage]

The u shaped part by #10?

https://www.cmsnl.com/honda-cb350k4-super-sport-1972-usa_model433/partslist/E17.html#results

Are you referring to the end of the oil passage on the left side in this picture? Yes, is that the same passage that lubricates the left side of the engine? If so, I'm guessing that my pump is working since there is oil here.

Well, it would seem like you are getting oil as it would've seized by now if not? And all your testing sounds like there are no blocks and the pump is working.
At risk of causing damage, try drying the inspection bolt and hole. Insert the bolt and remove. Once no oil residue comes off, try start up and let it idle a minute. Remove the bolt while bike is idling. Is it wet or dry? That's what I'd try if it was my bike...

As I mentioned, I've filled the top end with oil through the valve adjusting holes just to be sure not to seize the engine while testing, maybe this is the reason that it hasn't seized yet.

I will try with running the engine with the bolt in and then remove it. I've read a numerous amount of suggestions about how long time it would take for the oil to reach all the way up there, ranging from 15 sec to a couple of minutes, but when I'm passing two minutes without oil in the inspection hole I'm getting a bit nervous..

 

[doode]

I would definitely be nervous too. It's always nice to see the oil dribble from that hole after engine work, but also a bit of a scramble to get the screw back in to keep too much oil from getting everywhere!

Putting oil through the inspection covers won't do much for the cam shaft.

I hope you get this solved soon... Oil starvation after the rebuild is a huge bummer. Hope you used a lot of assembly lube!

 

[Armitage]

My next step will be to have another look at the oil filter cap and the oil guide to see if something isn't in it's best condition. But since most of the parts are exchanged for NOS-parts, it's not really obvious what it could be. The only thing I can remember from last time I had a look there was that the edge of the pipe on the cover (that reaches into the oil filter) was a bit nagged, could this have any effect on anything?

The u shaped part by #10?

https://www.cmsnl.com/honda-cb350k4-...7.html#results

If I open up the left side cover and get oil coming out of this hole, would that be sufficient evidence that the pump is working at least up to that point? Although I realize I'll probably have oil all over the floor if I open it up before before draining the engine.

 

[Armitage]

So I opened up the right side oil cover again, and when looking more closely at the oil cap I found that the condition wasn't the best, with a not so small piece missing as you can see in the picture. New one ordered, let's hope for this.

https://www.dropbox.com/s/iregauopp0lexhv/Fil 2017-10-17 12 40 24.jpeg?dl=0

 

[tbpmusic]

So I opened up the right side oil cover again, and when looking more closely at the oil cap I found that the condition wasn't the best, with a not so small piece missing as you can see in the picture. New one ordered, let's hope for this.

https://www.dropbox.com/s/iregauopp0lexhv/Fil 2017-10-17 12 40 24.jpeg?dl=0

The cam "bearing" gasket on the rider's left side is NOT symmetrical - if installed in a flipped configuration, the oil feed hole may be covered.
Only way to check is to pull it apart.

 

[Boomer343]

So I opened up the right side oil cover again, and when looking more closely at the oil cap I found that the condition wasn't the best, with a not so small piece missing as you can see in the picture. New one ordered, let's hope for this.

https://www.dropbox.com/s/iregauopp0lexhv/Fil 2017-10-17 12 40 24.jpeg?dl=0

That's not just missing a small chunk it is missing the steel ring wear surface as well. That surface should be smooth and flush with the top of the piece where the chunk is out.

I'd say that is a problem......

 

[Armitage]

Well I do hope that IS the problem! Let's find out when the new one arrive!

 

[Armitage]

Finally the new oil cap is in place and YES it works! I've got oil coming out from the inspection bolt in the top! What a relief. Thank you everyone who helped me figure this out.