Author Topic: Bike want's to creep forward in gear with clutch in, normal? SOLVED! (Read 22561 times)

Eaallred · « **on:** June 24, 2013, 06:10:59 PM »

Hey all,

I have a new-to-me 75 CB750. The problem i'm having is the bike wants to creep forward in gear, this also results in me not being able to get into neutral at long traffic lights, etc. I can shut the bike off, rock it a bit and get it to go to neutral, but now while running.

So far I've put a new clutch cable on it, put a good hand lever that doesn't have the pivot hole worn out, installed a good set of used clutch discs/plates, adjusted the center bolt on the clutch pack, adjusted the clutch cable, and put a bit more bend in the clutch arm behind the cover to effectively shorten the lever to make up for some of the slop/wear on the cable attatchment. This clutch is dialed in for sure now.

But still... It wants to creep forward and I cannot get into neutral with the bike running.

Any ideas? Or am I looking at a rebuild to fix this?

xsmooth69x · « **Reply #1 on:** June 24, 2013, 06:21:08 PM »

adjust this

pretty much when you pull the clutch its not fully releasing and its still partially engaged

the opposite of that is you clutch slipping with the clutch lever completely let go

just because the line is nice and tight dosnt mean its actually disengaging the clutch.

----------------

with the clutch isnt disengaging and the bike gets really hot its very hard to pop it in and out of neutral 1-n-2. if you sitting for a super long time in dead lock traffic start and stop the bike. these are air cooled remember

bjbuchanan · « **Reply #2 on:** June 24, 2013, 07:32:48 PM »

The first thing I think of when you say creeping at a light is that the adjustment isn't right. Are you adjusting a warm engine? Also remember to back off pretty far the cable nuts at both ends, free slack at the engine/clutch adjuster thingy. Tighten up, back off like ~1/4 turn and cinch down. Adjust primary play at the bottom engine side. Fine tune at the handlebar

Remember that this bike the clutch will engage "far out" compared to newer bike feel. If you ride newer stuff it will feel foreign to you. Don't adjust for where YOU think the clutch shoud start to be full out, adjust as you are SUPPOSED to do. I like to leave just a little extra play at the lever because that is more comfortable for me, but it is by no means where my buddies R1 starts to function

Also get used to "snicking" it in to neutral when you are still moving or rocking the bike to get it to slip in for you. It is the type of tranny, it is just how it is so you gotta adjust. Impossible to nail it tho is the clutch improperly adjusted, it is another clue that your adjustment is skewed

Best of luck with it
Brian

Eaallred · « **Reply #3 on:** June 24, 2013, 08:43:01 PM »

I appreciate your feedback, guys. I'll try to describe in detail how I adjusted everything. Maybe see what I am doing wrong, or if something might be wrong with my bike maybe? I just bought this bike a few weeks ago so I don't know it's history.

I loosen the clutch cable at both ends so it is not a factor. I turn the flat-head screw in the middle of the clutch to make contact, back it off 1/4 turn and tighten the locknut down. At this point I can feel the 'freeplay' on the clutch by moving the lever by hand. Very minimal movement, so I know it's very close.

I then move the adjuster at the handle so it is right in the middle of the threaded movement. Then I adjust the clutch cable on the transmission end to get proper freeplay on the handle. I get it real close there, then fine-tune with the adjuster at the handle.

The engagement is pretty far out on the handle like described how it should be. It all feels really good, except for the creep.

I found the handle pivot had worn badly, so I traded it for a better one off the parts bike. That helped a bit.

Tomorrow i'll measure how much inward movement I am getting at the clutch, maybe someone cam measure theirs so I can see how it compares.

david 750f · « **Reply #4 on:** June 24, 2013, 09:31:57 PM »

Does the clutch slip at speed? How old is the clutch cable? It sounds like the adjustment is off. With the bike on the centre stand and running in neutral, does the wheel spin?

Eaallred · « **Reply #5 on:** June 25, 2013, 05:24:17 AM »

It is a brand new clutch cable. I have it adjusted so it won't slip when pulling hard in the powerband. When going down the road, with a light load on it, right as I pull the clutch handle in the rpms come up. There's definitely no slop to the adjustment.

It does have longer than stock clutch springs in it. I tried swapping the stock springs into it from my other 750 but that didn't change anything other than it slipped in the powerband. Still creeped in gear with clutch in. Not sure what this motor has had done to it, but I know it has been "rebuilt" at some point.

Seems regardless of what someone may have done during a rebuild, the clutch shoild be able to disengage from it, no?

Eaallred · « **Reply #6 on:** June 25, 2013, 06:36:53 PM »

Measured the movement of the clutch, getting 0.093" inward movement. Anyone able to measure thiers to see what I can compare that to?

Eaallred · « **Reply #7 on:** June 26, 2013, 03:37:26 PM »

Bump,

Anyone able to measure the total movement inward of their clutch so I can see if it's a cable issue, or something internal that needs attention?

Eaallred · « **Reply #8 on:** June 26, 2013, 10:14:39 PM »

I apreciate the info. Looks like my clutch movement is not out of whack. Need to dig further to see what is going on this weekend.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #9 on:** June 26, 2013, 10:59:56 PM »

There were 2 basic clutch packs with the newer one going in the 77's. There is a 'field upgrade' too for the earlier ones. This could be a mix and match situation. Sooooo, if you get inside.......

Newer cover on right with notched 'fins' for later clutch pack that is wider and unnotched earlier one

Newer basket (longer) on the right that fits with the double metal disc in the middle

Newer pack with the double disc installed

Both use 7 friction discs HOWEVER the field mod uses 6 friction discs with the double metal disc replacing a single metal disc

Eaallred · « **Reply #10 on:** June 27, 2013, 06:18:56 AM »

Good info here, i'll inspect for worn grooves.

Both my 'current' bike and my 'parts' bike are 75's, which is nice. Maybe i'll pull both clutch assemblies out and mix/match the best parts and throw in a new clutch kit for good measure.

Anyone recommend a good hotstreet clutch kit? Been looking at the +1 kit from Dynoman http://dynoman.net/engine/clutch/dp.html . Any other recommendations?

Eaallred · « **Reply #11 on:** June 27, 2013, 06:22:41 PM »

Found something today.

Pulled the clutch out, this time pulled the clutch basket out. Couldn't see/feel any ridges or steps caused by the clutch discs, but some sticky sludge was present. I solvent tanked the basket, and cleaned the discs and plates on the clutch. I re-oiled everything really well with 10/40 bike oil and put it in. With it all the way in I noticed the clutch pack had no free play when pushed all the way in. The four pedestals were not able to move a bit, which told me the clutch discs would not fully release. Hmmm. Pulled it back out and started looking at it. I could see the clutch basket was rubbing slightly on the aluminum clutch assembly. I started thinking "Man, there should be a washer or shim behind this to hold it away from the clutch basket, that would give me space. I went over to the parts bike, pulled it apart and found there is in fact a spacer that should have been there

Seriously? I've only had this bike a couple weeks, so whoever rebuilt the powerplant forgot a piece. Dang it.

So with everything cleaned up really well, lubed up with fresh oil and reassembled with the spacer in there, I try it out again.

Still creeps a bit. Not as much, but there is still enough tension that I can't shift the bike to neutral with my foot when idling in 1st. I can with my arm if I pull hard. But it does shift a LOT better when riding it around. So at least there is some improvemnt there.

Wonder if the clutch disks are burnt or something (from constantly dragging), making them a bit sticky/draggy. Will order a new set of discs and see what that does.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #12 on:** June 28, 2013, 11:57:52 AM »

OK, your bike is a 75 and it has the shorter basket (I'm assuming?). You found that magical washer in another bike. What year was that bike?

Reason I ask these questions, there are 2 different 25mm washers used.

The larger one is from my 75 750 with the old shorter basket and the smaller one is from a 78 750 which uses the longer basket

Eaallred · « **Reply #13 on:** June 28, 2013, 04:17:42 PM »

The plot thickens......

Both of my bikes are 1975. The current 'rider' didn't have the washer, but the 'parts' bike did. I know the current bike has been gone through (poorly, judging by the oil leak) at some point, but the parts bike looks to be untouched (which I know, means nothing really).

Is there a thickness difference between the two washers? The parts bike runs (or did run before I tore into it) and it didn't creep in gear. Maybe I should swap the basket over or at least pull it to see if there is a difference. I believe they are both the short baskets.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #14 on:** June 28, 2013, 04:44:29 PM »

I believe (don't have both available to double check) they are the same thickness. The larger one sits 'outside' and is not recessed inwards like the smaller one thus taking up more potential free space.

harald · « **Reply #15 on:** June 29, 2013, 05:21:35 AM »

Had the same problem because I used car motor oil which made the clutch slip. Check your type of oil.

bjbuchanan · « **Reply #16 on:** June 29, 2013, 09:24:13 AM »

Unless you are rocking the bike you aren't slipping in To neutral at a dead stop unless you just got real lucky. Proper oil and clutch adjustment helps but they don't just slip in to neutral at rest. It is the type of tranny

Eaallred · « **Reply #17 on:** June 29, 2013, 07:19:24 PM »

Mobil 1 motorcycle 10w40

grumpy · « **Reply #18 on:** June 29, 2013, 08:38:53 PM »

Quote from: bjbuchanan on June 29, 2013, 09:24:13 AM

Unless you are rocking the bike you aren't slipping in To neutral at a dead stop unless you just got real lucky...they don't just slip in to neutral at rest. It is the type of tranny

On a 750 K5?
I've always been able to get N without rocking - I have a K3 and K5 motor - no problem.

I just measured the thickness of the spacer on the right (above): 3.15mm

BTW - aren't those supposed to go in a certain way?? Like rounded edge in or something?

Eaallred · « **Reply #19 on:** July 24, 2013, 06:31:49 AM »

Got it fixed finally. I haven't ridden it in a few weeks as I've been swamped at work and going 7 days a week trying to keep up.

I put some SeaFoam in the oil and drove it about 50 miles or so. When the bike started shifting a little clunky, I changed the oil. Drained the case, the oil tank, and changed the filter. Kicked the motor over a few times to make sure everything was pumped out.

Added fresh oil and let it warm up. I can shift it into neutral while idling now and it doesn't creep forward!

I just bought the bike this year, and the oil was clean when I bought it, but it may have been a quick oil change before selling type thing. Now that it's all cleaned out good, it works fine. So between the gunk in the motor and that missing shim, it was really having issues. Feels great now.

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Author Topic: Bike want's to creep forward in gear with clutch in, normal? SOLVED! (Read 22561 times)