Carb sync and clutch rattle

[ajs350]

While my 80 is now all done and running well I am still not able to eliminate the clutch rattle at idle. I'm beginning to wonder whether I should have spent a little more on my gauges? Has anyone else used these gauges with success?
I even took the faces off and adjusted each dial to the same point while connected to #6 carb to ensure each gauge was reading the same at a given vacuum.
Ross

[EMS]

The clutch rattle will not go away completely. It may also be the primary shaft that contributes to the noise somewhat. Synchronizing carbs helps, but as I said, will not completely eliminate the noise.

[Kool_Biker]

So Mike

What is the issue with the primary shaft?
And going through my new nut and bolt re-re-storation (no laughs pls) what is it that needs to be checked and in order there?

Cheers, Aris

[daves79x]

Aris and Ross:

The issue with the primary shaft is that Honda changed the design in '80 (which yours would be Ross), then yet again for '81 and '82. The complete '81-'82 clutch/primary shaft set-up is the best and quietest. A basket fix for both of your bikes would solve most of the noise - especially yours, Ross. Six Center in Holland makes a nice do-it-yourself kit. Or pay $500 for a late model basket.

For you, Aris, finding a complete late primary/clutch basket would be great, but not cheap. There are also a couple of other part #s you need I think also for that complete swap, mainly associated with the starter/idler gears. But everything is a direct bolt-in swap. The later shafts are secured with a ring nut similar to the clutch hub nut. There is no upgrade in strength or anything else - just tighter.

Late primary shafts are easy to find - not so easy for the baskets. I'd do the biscuit fixs to your baskets and let it go at that - it works.

Dave

[ajs350]

Thanks guys. Looks like I've got myself a winter project to look forward to.
Ross

[Kool_Biker]

Cheers Dave, have already opted to have the biscuits fixed and keep the original 79 arrangement.
Aris

[Don]

If you run across an '80 basket for a reasonable sum, 'fixing' it would be an even better option than staying with the '79 basket as it contains 9 of the biscuits compared to just 6 in the '79

How long the 'biscuit fix' will solve the problem is still an unknown because I don't think anyone knows how much better (if any) the new rubbers are than the OE Honda ones - I suppose most all forms of rubber deteriorate with age when running in hot oil

If you can find a ProLink basket for a reasonable sum, it's the permanent answer to everything. I paid $350 for mine (plus a new set of friction discs) and I think it was worth every penny - All of the clutch noise is gone . . . . which allows you to hear other things you didn't even know were there ;) It's another of those things that Honda finally got right with the later version of the bike

Don

[Mike Cecchini]

Hey Don/Dave...... I'venver heard of clutch "biscuits'. Can you explain or show pic ?

Thanks........Mike

[EMS]

If you run across an '80 basket for a reasonable sum, 'fixing' it would be an even better option than staying with the '79 basket as it contains 9 of the biscuits compared to just 6 in the '79

Don

In case you do not want to attack this yourself, Tom Whaley of Springfield , Oregon used to do this for others. I have not seen him here in a long time and he may no longer be doing it, but I think he checks in on CBXWorld frequently (aka rocketman)

[NobleHops]

He is a super nice guy, and did mine for me 2 years or so ago when I dug in in earnest. I don't have a frame of reference for how noisy it was before, but I'll just say I do not notice anything untowards about my bike at idle now, and (shameful admission) I am still running with the bench sync that Mike Nixon did when he rebuilt my carbs.

P.S. I think the 'biscuits' are also referred to as 'rubber isolators' or more simply 'isolators'.

N.

[Don]

In case you do not want to attack this yourself, Tom Whaley of Springfield , Oregon used to do this for others. I have not seen him here in a long time and he may no longer be doing it, but I think he checks in on CBXWorld frequently (aka rocketman)

Pretty sure he's no longer in the business - I bought one of the very last sets he sold a couple years ago. He was using some sort of product that came liquid in a tube and molding and cutting the biscuits. Later on I read of one or two cases where those broke down after a few thousand miles . . . . sooner than the OE parts, so I never installed mine and just kept up the hunt for a ProLink basket. Some time later, Six Center came out with their kit and they are supposed to be better quality isolators

The biscuits, rubber pucks, isolators . . . . whatever you want to call them were replaced with springs in the ProLink baskets - Thety look much like the setup used on clutch discs in automobiles

Don

[Mike Cecchini]

He is a super nice guy, and did mine for me 2 years or so ago when I dug in in earnest. I don't have a frame of reference for how noisy it was before, but I'll just say I do not notice anything untowards about my bike at idle now, and (shameful admission) I am still running with the bench sync that Mike Nixon did when he rebuilt my carbs.

P.S. I think the 'biscuits' are also referred to as 'rubber isolators' or more simply 'isolators'.

N.

Gotcha on the "biscuits". Since I've synced the carbs nicely (omg how touchy they are), my 80 clutch noise has dropped 80%...... so it's no longer an issue to me. Frankly, to me it's just one of the sounds these engines make.....and like Ducati's dry clutch..... it's part of the bike's flavor.

Thanks.

[piit]

About gauges. I have used different gauges also Carbtunes and frankly said never trusted completely. So, I made home mabe gauge where can be trusted 100%. It was interesting to see level differences between Morgan Carbtune gauges and home made gauge. The last picture is checked after Morgan Carbtune synch, terrible! The second picture after re-synch with this home made gauge, very hard to get levels closer. The first picture shows how home made gauge is always self calibrated.
Why to spend money on commercial gauges if the best one can be home made and cost almost nothing?! Many of you might have similar home made gauge but never seen any post in this forum, so that´s why I wanted to share my experience.

[Mike Cecchini]

Good thinking Pitt.......and whatever works for you and gets the carbs synced properly. I've been using the same set of mercury carb sticks since 1975 and they work well for me.

Thanks for the pics !!

My best.............Mike