Best place for a clutch replacement kit?

[pen]

I understand that these bikes are pushing 50 years these days but surely there’s still a way to get new clutches (plates and springs) for them right? I’ve done some digging online and found only one place that seems to sell it as a kit. After a little more digging on some more common sites (cb750supply and 4into1) you can buy the individual plates and springs, and those are great, but honda put different plate variations in different years/models? (f and k). The engine on mine isn’t original to the bike, so I don’t know exactly when it’s from, and vin lookup sites are useless because they all want 17 character vins! Ultimately, this post comes down to this: are the plates/springs between years and models interchangeable, and/or is there a way to definitively determine what year the motor is without the original bike?

 

[dirtdigger]

number stamped on the engine by the starter will tellyou what it is. post here and can tell you what you have.

 

[pen]

RIGHT! So I initially thought that the engine on my bike wasn't original to the bike because the code on the engine was different to the number on the frame. It turns out, and what you probably already knew, was that they wouldn't match anyway?! The number stamped reads CB750E-3018948 which, after being confused by the E in there and looking it up, I found out that the engine not only is from the '78 model, but that it's also probably original to the bike! Now that returns to the question, where and what do I need to do a full replacement of the clutch right?

 

[pen]

As a side note, the reason I need a new clutch is because it's slipping. Though, after a little bit more research, I wonder if it has anything to do with the oil I'm using right now either.

 

[dirtdigger]

Yes oil can make the clutch slip. Needs to be a motorcycle oil that is wet clutch compatible. most automotive oils are not compatible.

 

[pen]

Yes oil can make the clutch slip. Needs to be a motorcycle oil that is wet clutch compatible. most automotive oils are not compatible.

Well that's no good. That's like all there is in it is generic car oil. Can I just change the oil to a motorcycle oil and be on my merry way, or is the clutch system now in dire need of replacement?

 

[dirtdigger]

Might as well try it, nothing to loose other than the cost of the oil. It kind of depends on the condition of the clutch. It may take a bit of use to work the old oil out and see if it will work.......it still may slip for a little while or it may work good right away when you get the new oil in the clutch. Hard to say. I use Valvoline motorcycle oil or Amsoil motorcycle oil.

 

[Biebs]

Rotella T4 15/40 is a motorcycle rated oil and cheap.

 

[dirtdigger]

Little thick for my liking in these bikes for non racing use in my opinion. May be ok in constant warm climates. Kind of depends on the application. I dont like heavier than 10-40 with small plain bearing motors with tight clearances like these.

 

[pen]

I’m sure this situation has rarely ever happened on this forum, but I’ve got the oil drained entirely in this moment. Would it be a bad idea to remove the clutch assembly and spray the plates and disks with brake cleaner to try and get that old oil out? Or should I just fill her up and hope for the best. This small mistake seems to be potentially costing me a lot right now.

 

[dirtdigger]

Wouldnt hurt anything as long as the brake clean doesnt leave a residue. I wouldnt soak it but just spray it with a cleaner. Its worth a shot.

 

[Biebs]

You would be better served just adding new oil and see how it runs. 40 or 50 miles
If that doesn’t work add 1/2 quart diesel to crankcase run engine on center stand shift through gears.
Only run for short period of time less then5 minutes. Then change oil.
The diesel will help clean the clutch plates and engine.

always ran diesel fuel mixed with oil in old bikes that sat for years.

 

[dirtdigger]

I do not suggest anything in the oil that "cleans" the engine on these. The oil orfices to the cam bearings is EASiLY plugged. Many top ends ruined in these motors by foreign debris plugging the orfices.