Topic: Carb Sync Results / Clutch Concerns

[Dr. Noisewater]

Hey guys gonna try to hit two birds with one stone. The bike is a 75 CB550F

I finally got a carbtune a few days ago and sync'd my carbs this morning. They weren't far off but it definitely smoothed it out. The carbtune is pretty sweet, but I now understand why people spring for the brass adapters. The normal plastic ones are just scary, mine were a little tough to thread.

Anyway, from what I read the proper procedure for my bike was to determine which cylinder is pulling the highest vacuum, leave it alone, and bring the other 3 to its level. So that's what I did, but I'm curious if there's a particular vacuum they're supposed to read, or does that just depend on the idle and as long as they're equal it's good?

Secondly, after finishing the tune I took it for a spin. Definitely felt a little more responsive and smoother, but I noticed my clutch slip when I accelerated hard out of second.

I tried to adjust my clutch a couple weeks ago because the clutch grabs at the very last chance it can before the lever is completely out. The adjuster on the clutch cover acts a little strange. The only way the dot on the lever and the dot on the cover will line up is if the adjuster screw is all the way out. If I screw it in (clockwise) at all I lose all function of the clutch. Anybody have any idea what the issue could be?

Thanks for the help.

[dave500]

so long as the vacuum is the same its fine,ignore those dots on the clutch mechanism,turn the screw clockwise for more clutch grab,adjust the cable aswell.

[Dr. Noisewater]

So if I screw in the adjuster it'll bring the grab point closer to the bars?


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[dave500]

it will give the clutch pack more bite,where and how the lever behaves is determined on how you adjust the cable.

[LesterPiglet]

Loosen the adjusters at the bars and on the cable. Take up the majority of slack with the case screw. Bring it closer with the cable adjuster then fine tune at the bars.

[Dr. Noisewater]

This is driving me crazy! I played with it some more and tried your method, it resulted in the bike jerking forward after putting it in gear (clutch in) and soon dying. The problem might be the custom clutch cable from motionpro. The inner cable was too long in relation to the black housing. I tried to mend it with a long hollow spacer that fits inside of the adjuster on the lever but maybe it needs some revising. If only motionpro made stuff that worked!

I'll continue the trial and error in the morning.

[dave500]

with the cable disconected at both ends pull all the slack down toward the case,you should have three inches.

if you cant adjust the clutch properly and the cable is good youll need new friction discs,once worn you cant find the sweet spot,itll either slip or not disengage fully and go clunk heavily into first and maybe even stall?

[Dr. Noisewater]

Thanks for the measurement, Dave. I compared mine this morning and I had about 4.75". I made a spacer up top to take up some slack, and got it pretty close. Here's some pics.





After getting everything hooked up I tested it out. The adjuster screw was all the way left (counter-clockwise) when I started and the clutch grabs really far out and seems to slip. I screwed the adjuster screw all the way clockwise, re-adjusted the cable slack, and it behaves the same way. What am I missing?

[dave500]

that looks like a 500 cables length?get a proper 550 one,you might have a two fold problem,#$%*ty cable and worn clutch plates?

[Stev-o]

I stay away from Motion Pro cables, too many guys have had similar issues.  Spring for the proper Honda...

[Dr. Noisewater]

The only reason I got motionpro was because I went to clip-ons and the factory clutch cable is far too long. At least mine was. But the bars that came on my bike may have been taller than factory which might mean someone went for a longer cable sometime in the past. Who knows.

I still have the old cable, anybody have a spare they could measure for comparison?

[dave500]

if the old cable has three inches free is its entire length too short?

[Dr. Noisewater]

No it's too long for my setup. The more I think about it though, it really doesn't matter how long or short the cable is. All that matters is the relation between the inner cable and the black housing.

I'm just gonna ride it for a little. The clutch seems to be a little better than before. It seems to shift smoother and find neutral easier, and I haven't gotten it to slip again. But it still grabs pretty far out. I need to ride it more though to really grasp how it behaves. Thanks for your help Dave.

[Stev-o]

Did the bike sit for a long time?  If yes, put some miles on it and it may improve. 

[lucky]

When a clutch slips you can not "adjust it" into working.

You will need new friction discs. If you continue to ride it with the clutch slipping then when you finally replace the friction discs the metal plates could be warped and ruined and then you will have to buy the metal plates between the friction discs too.

If the motorcycle was sitting for a long time that can cause the friction discs to be glazed over and need replacement.

[AJK]

If you need to shorten your cable, this link might open up some ideas. The end is not the same, but you might get creative in making a cup mould to suit the end of the cable.

http://www.chopcult.com/forum/showthread.php?t=166

[calj737]

This is driving me crazy! I played with it some more and tried your method, it resulted in the bike jerking forward after putting it in gear (clutch in) and soon dying. The problem might be the custom clutch cable from motionpro. The inner cable was too long in relation to the black housing. I tried to mend it with a long hollow spacer that fits inside of the adjuster on the lever but maybe it needs some revising. If only motionpro made stuff that worked!

I'll continue the trial and error in the morning.

I may be wrong, but it sounds very much like you were close here. If the clutch was adjusted at the side cover all the way clockwise, then you needed to back it out in 1/4 turn increments until it stopped dying when engaging the gear. This would be symptomatic of the clutch cable not fully releasing the clutch pack.

After you get the side cover "right", then fine tune the cable at the lever. I recently underwent similar issues with one of my bikes. I'd swear it was "Black Magic" until a seasoned pro showed me and explained it clearly. Dave's explanation is spot on, but I think, (Dave please correct me if I'm wrong) that you just needed to back off the adjuster a tad and try the lever.

[Rgconner]

If you have a typical EMGO set of vacuum gauges then you need to calibrate them.

Hookup to cylinder 1 or 4, but just the one cylinder.

Hook up the first gauge, write down the reading. Move the tubing to the next gauge. Fiddle with the calibration screw on the gauge so it reads the same as the first one.

Rinse and repeat for the rest of the gauges.

Now, don't worry if it is RIGHT or WRONG, just so they are all the same amount of RIGHT or WRONG.

And use your ears, you can't balance by ear, but your ear damn well will tell you when you get it right!