Oil feed to clutch cb750k

[Pauarc]

Just had a Quick Look at plug came straight out with no problem. No damage just had a little bit of sealer on the end turned over on start motor oil comes straight out see picture will have a proper look at the weekend and check the bearing outlet through to the clutch

[Nurse Julie]

Looks good. Is the plug rubber and has it got a groove around it?

[Pauarc]

Yes it’s rubber and still pliable, and it has a groove round it Like a top hat

[Oddjob]

So I'd imagine the rubber bung is to plug up the oil gallery where it's been drilled to force oil to go up the 2 towers that look to be connected to that gallery, these towers look to be feeds for oil into the centre of the gearbox shafts, the longer tower I'd say is the feed for the clutch shaft, if there is oil at the bung and not at the clutch then it must be that one or both of these tower galleries are blocked, most likely with a blob of sealant. I'd try some compressed air down them to see if it blows it out, failing that you may have to dismantle the engine and really get in there to get whatever is blocking that feed out.

Try compressed air down from the clutch side first to see if you can feel it around the bung area.

[Pauarc]

Yes that was my thought too so clutch cover coming off again and remove bearing holder select end and clutch so I can poke something through and blow it through with the air compressor looks like my weekend is gonna be taken up on the bike hopefully I find something blocking passage way

[Martin6]

I have a nice selection of guitar strings of various guages, if you are looking for something to clear the oil passage. 👍

[Pauarc]

Thanks Martin I will bear that in mind how The bike going

[Martin6]

Picked up the frame and brackets today. Nice and shiny  So, the putting it back together, begins.

Tried to fit the centre stand. Needs some serious muscle on the spring. Will try again tomorrow.

[Oddjob]

If the frame is bare Martin try fitting the pivot bar and lifting the stand up inside the frame and you will find the spring just falls on when you do that. Works on the 500/550 so in theory it should also work on the 750.

Oh and really grease up that pivot bar before fitting

[Pauarc]

All cleaned and blown through and clears found nothing which would be blocking it

[Pauarc]

Do you think it’s would be ok to run with cover off to see if oil comes out of the hole in centre of clutch after fitting gear shaft bearing and plug

[Oddjob]

You tried to see if there is anything inside the gearbox shaft itself?

[Pauarc]

I have had a bright spot light shining through from clutch side and it shines through onto a piece of paper and also a long pipe brush down the centre to other side and a air line as well

[Oddjob]

I fail to see how oil isn't coming out of the shaft and onto the clutch plates, IF oil is at the bung, the transfer towers are free and clear and the shaft itself is free and clear why no oil ? Only answer I can think of is that the bung is blocking the gallery somehow. When the transfer tower part is removed and the bung is in place does oil come out of the hole where the bung is forcing it to go?

Another possibility, when you removed the transfer tower plate was there an oring around the hole where the oil would come out? if that was missing it's possible all the oil being pushed through would just leak into the gear area close by, especially if the plate isn't exactly flat, should be one of these fitted around that hole https://www.cmsnl.com/honda-cb750k2-four-england_model14363/o-ring-5x24_91301283000/

Might be my imagination but there does seem to be a very clear track leading to that gear area from the oil exit hole.

[K2-K6]

Do you think it’s would be ok to run with cover off to see if oil comes out of the hole in centre of clutch after fitting gear shaft bearing and plug

With ONLY that clutch cover off, it should be ok to run it like that.

All left hand side bearing plate, cover and gasket to be installed fully though.