Topic: APE clutch w/ 1978 750F issues?

[Bamboozler]

Wondering if someone can shed light to my dilemma.  I searched but couldn't find anything that addresses what I'm running into.  I bought an APE 9 fiber clutch to replace my slipping stocker.  On the website it says their clutch works with all models through 78.  I got the clutch from UPS yesterday and saw that the sticker says "through '76". I call the tech at APE a he said it was a probably a typo on the sticker and that the clutch would work with my 78F.  So I took the fibers and soaked them in a oil bath overnight. 

Today I pulled the stock clutch and first off noticed I needed an extra steel plate in addition to the two steels included (which I've read prior while searching about this clutch).  I did not assemble with the outer thick fiber B plate or the double steel.  After pulling a steel from the basket case 78F I installed all the fibers and proceeded to install the stack into the outer basket... but it didn't fit.. the diameter of the fibers were much too wide.  The fibers just barely cleared the case itself..

Did someone package fibers for a different bike in the blister pack?  Has anyone else ran into this road block and have a work around? 

Picture attached shows the how much wider the APE fiber is verses a stock fiber.  Any help is appreciated.

[eurban]

I had issues with the APE clutch on my 78K.  One was that (as you found) you are unable to use the double thick center steel (stack height is too high) so that you need to source an additional regular thickness steel to make the assembly.  The late clutch baskets also have a wider section at the end of the "fingers" to accommodate the wider tanged B disc that is installed last.  The APE clutch fibers are loose fit in this portion of the basket.  In use, the clutch functioned for the most part but shifting was not particularly smooth and the clutch squealed occasionally, most often right after start up. Neutral was impossible with the engine running. My engine is an 836 and I have happily switched back to the stock setup with stiffer springs and no slippage. . . . . I did not notice a difference in diameter of clutch fibers however so something is clearly off with what you received.  The proper ones will fit into the basket and you must have incorrect parts in your package. When you do get the correct parts, you might consider a bit of experimenting.  The late clutch assemblies are deeper so that when you ditch the double plate center and install the APE setup you are actually a bit short in stack height.  Perhaps the solution is to use the wider tanged B disc instead of one of the thin APE discs in the outer most position thereby eliminating two issues?  See what you think.  Its been a while since I played with this and my memory is a bit fuzzy . . .

[Bamboozler]

Thanks for your reply Eurban.  I came across your prior thread and posts while searching the archives and thanks to them knew about the third steel that was needed.  The posts regarding your dealing with this clutch kit made me question if these are for a Honda at all, being that you have the same year bike and had no problems getting it installed.  Though I wasn't 100% the K and F were the same, or if you had a basket from another year bike.  Looks like I'll be giving APE a call and seeing if I can get this straightened out.

Thanks for the input for final fitment. I took pictures of the stock clutch stack being pinched with a dial caliper and did the same with all APE fibers too. I didn't study the numbers because I documented it with the camera. Now the camera doesn't want to cooperate and I can't see what numbers are.  I do like your suggestion with using the thicker stock B plate in place of one of the nine APE fibers. I'll give it a try and see what happens, I'll post my finding in this thread.  Jay says this clutch will hold power and I'm slipping on stock fibers and Barnett springs so I'd like to see this clutch work and end my problems.  The other idea is to give a Barnett clutch a try, but I'm thinking all should be well if I get the correct fibers.

Thanks again for the sanity check, info, and suggestions!

[Bamboozler]

I've been out of country for the last two weeks and finally got some time to hit up the clutch.  I had called APE regarding being sent fibers from a different application. I sent some pictures and explained the situation and they handled the situation very professionally and sent me out the correct clutch promptly, props to APE.  I let the fibers soak for a day and took some measurements again tonight prior to installing the clutch.

With a caliper I measured three flavors of the whole assembled clutch, from the pressure plate to the clutch center that fibers and steels slide over.  The three flavors were the original stock clutch, the clutch assembled with all 9 fibers from the APE kit, and lastly the APE kit with the thicker "B" fiber that Eurban suggested.  Numbers are below, maybe someone will find it useful.  

Stock clutch with used Honda fibers (78 750F, ~15,000 miles unless changed by the PO) ~2.225-2.230 (averaging the measurement from around the stack)

APE clutch with all 9 fibers ~2.200

APE Clutch with 8 fibers and the thicker Honda "B" fiber ~2.240-2.245

I installed the APE fibers with the thicker Honda "B" fiber, it may even be the same thickness as a new Honda set of fibers??.  I media blasted the steels too.  It was raining tonight so I didn't get to see its drive characteristics yet.  When it was started I didn't hear any more noise than what I had with the stock clutch.  I did notice that finding neutral is now much more difficult as Eurban noted.  I think I only got it into neutral once out of probably 15 over and under shoots; and that's with rolling it forward to cheat it in too . It does have a more noticeable "CLUNK" (harsh if you will but nothing of concern) as its put into gear while running.  I'll update how it rides for the archives when I get a crack at.

[Bamboozler]

Follow up to my clutch slipping problem.  I will have to attribute being a bit of a nob while adjusting my clutch which could have had a big part in my slipping clutch.  My few rides with the APE clutch and double thick stock "B" fibered turned up another slipping clutch.  After I reevaluated the situation I concentrated on my cable adjustment on the motor side. I had noticed that I had been preloading the clutch arm/spring which was causing the clutch to be ever so slightly disengaged, attributing to the slip I was seeing.  After adjusting the clutch "course" adjustment to where it just started to move the arm/spring I locked it in place and fine adjusted on the hand lever side... The slipping was history.  Makes me wonder if I could have gotten away with the stock fibers and Barnett springs...

I do notice with the APE clutch and "B" fiber installed it's not as harsh as I first thought.  Finding neutral is still a tiny bit more difficult but much improved over what it was like just before.  All in all it seem to work good and I'm satisfied. It's able to hold 9psi of boost with no noticeable signs of slipping.