Author Topic: Clutch Not Holding Under WOT: RECTIFIED  (Read 5448 times)

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High On Octane

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on: August 18, 2013, 04:17:30 pm
The Blackhawk is running great!  I'm pretty sure the last problem I had was due to the loose wire on the coil ground.  But alas, another problem arises.  Friday and Saturday night I was out hot rodding around town, and while the bike ran like a beast I was having trouble getting the clutch to hook up under 3/4-Full throttle.  The bike was pulling so hard that the clutch would slip until almost 5000RPMs.  I know people have reported issues with this before, it sounds like these clutches are known for having weak basket springs.  When I had it all apart a couple months ago doing the alternator/rotor the clutch plates still had plenty of material left and I'm thinking that there still is life on them now.  I'm thinking my problem is from when the return oil pump got clogged and dumped all the crankcase oil into the primary.  I have a feeling that the friction modifiers in the engine oil has left a coating on the clutch plates.  Any recommendations on how to clean them up WITHOUT pulling the primary cover?   ???   I've had that damn thing off to many times and am in no mood to pull it again unless I have to.  Thanks.

Scottie
« Last Edit: June 18, 2014, 12:55:44 pm by High On Octane »
2001 Harley Davidson Road King


classicrider

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Reply #1 on: August 19, 2013, 04:48:47 am
Scottie,i remember years ago using water based degreaser (pretty cheap and came in 4 liter container) in the primary(yes you will have too break the seal on the primary but at least won't have to remove it),i just poured a good litre in there and went for a slow ride around the block working the clutch a few times then dumped that and then use ATF F ,that can actually be a little too grippy for smooth takeoffs,but at least it works.
colin
« Last Edit: August 19, 2013, 04:53:03 am by classicrider »


High On Octane

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Reply #2 on: August 20, 2013, 01:56:52 pm
Changed out the oil to Type F ATF.  It's slipping less and seems to fully engage sooner than it was but definitely still slipping some.  Hopefully after a few more miles it will settle in.

Scottie
2001 Harley Davidson Road King


Ice

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Reply #3 on: August 21, 2013, 03:38:04 am
 My spydy sense tells me friction modifiers are not the root cause of the slippage.

Just a hunch.
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High On Octane

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Reply #4 on: August 21, 2013, 03:47:37 am
Me too.  Shitty springs?  Are stiffer springs available?

I actually just took the Blackhawk to get a beer and it's weird.  I can tell the clutch is slipping but the bike is freaking screaming and even with the clutch slipping it feels like it's accelerating faster than before.  It's running AWESOME right now!  If I can get that clutch to hook up I could lay a nice 1/4 mile time down.  :D

Scottie
2001 Harley Davidson Road King


High On Octane

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Reply #5 on: August 21, 2013, 04:17:37 am
NEXT STOP, Old Chicago!  Clutch isn't slipping at all at less than 2/3 throttle, only when I'm in it to win it.

Scottie
2001 Harley Davidson Road King


High On Octane

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Reply #6 on: August 21, 2013, 02:54:49 pm
Okie Dokie.  The Blackhawk is my hot rod, and all though I smoked a chick in a new Mustang Friday night, I need to address this clutch issue.  The bike is clearly producing more power than this clutch was originally intended to handle.  Hitchcock's has SEVERAL options for improving the clutch.  I'd really like to upgrade to the belt drive setup, but my wife would cuts my balls off and feed them to me if I spend another $700 on my bike for a single part.    :P

I'm thinking of doing the Clutch Service Kit (Improved) - 7th listing from the top Part# 90222
And possibly the Pressure Plate Kit - 10th listing from the top part# 90043

http://www.hitchcocksmotorcycles.com/accessory-gearbox-clutch-primarydrive

Thoughts/Input?   ???

Scottie
2001 Harley Davidson Road King


D the D

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Reply #7 on: August 21, 2013, 03:05:07 pm
I wish they said who made the plates.  They list some that are EBC and Sureflex which guarantees the quality.
Check the warranty and recommendations for whatever you get 'cause EBC used to state that running ATF in the primary voided their warranty.
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High On Octane

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Reply #8 on: June 10, 2014, 03:19:06 am
Well, here I am again.  Brand new clutch plates and springs and the M-F'er is still slipping really bad.  It wasn't slipping at all when I first installed the new clutch, then I was inside the primary and refilled with Advance Auto Type F and it started slipping like a punk beeotch again and hasn't stopped.  It's even worse now, anything over 1/3 throttle and it breaks loose and revs up.  Just to prove a point to myself, I loosened the clutch cable while riding to where the lever didn't even work and it still broke loose.  If I bump/touch/hold the clutch lever at all it completely breaks loose immediately as soon as I put any tension on the cable.  Is something not right inside of the primary?  Did I install something wrong?  I'm at a total loss here and it's really pissing me the F off. 

ANY suggestions are better than none at all.  Please help me out.  :(

Scottie J
2001 Harley Davidson Road King


ace.cafe

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Reply #9 on: June 10, 2014, 04:04:51 am
You could try to scuff up the metal plates with very coarse emery paper
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High On Octane

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Reply #10 on: June 10, 2014, 12:13:06 pm
You could try to scuff up the metal plates with very coarse emery paper

I had actually thought of this and may do it, but the steel plates are brand new as well and appeared to have a nice texture to them.  But as I was laying bed last night I had a thought.  Like I mentioned, the very moment I put any tension on the clutch cable what-so-ever it revs up freely.  Is it possible that the clutch adjustment itself (the scissor mechanism adjustment on the basket) is already out of spec and holding the basket slightly open?  ???

Man, I really need to get a Newby......
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High On Octane

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Reply #11 on: June 10, 2014, 01:16:48 pm
Well I adjusted the scissor and put a little more slack in it but it didn't help too much.  So I added some Lucas Stop Slip for automatic transmissions and it definitely helped.  I can at least get on it a little bit now without it revving freely.  I have a feeling I need to go back in there and disassemble the clutch, clean all the plates with brake cleaner and then sand the hell out of the steel plates with some emery cloth or 80 grit paper or something of the sorts.
2001 Harley Davidson Road King


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Reply #12 on: June 10, 2014, 01:40:14 pm
Scottie - do you have any excessive radial play between the clutch centre and the basket [like big end play] ? This could cause creep between the plain and the friction plates, due to the forward 'pull' exerted by the engine and induce slippage. Other than that, is there any end float at the clutch centre / mainshaft [should be none], or is the clutch operating mechanism 'bottomed out' somewhere when there is slack in the cable - I have no experience of the scissor clutch, but I am thinking along the lines of when a clutch operating arm can go hard against the inside of an outer gearbox cover and cause slip, even with slack in the cable?
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High On Octane

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Reply #13 on: June 10, 2014, 01:58:24 pm
The clutch basket definitely has some play in it, but I'm sure that is the problem as it WAS working great before.

FWIW  This what the scissor assembly looks like.

« Last Edit: June 10, 2014, 02:01:57 pm by High On Octane »
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gmmechanic

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Reply #14 on: June 13, 2014, 01:08:51 am
I had a similar issue with my old shovelhead years ago...what I found was the slots in the basket had become enlarged slightly and deformed , causing the plates to cock sideways ever so slight but just enough to prevent smooth sliding...of course I was hard on a bike back the ;D ;D...just s thought... 8)
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