clutch problems

[Paul]

Paul
I recently purchased my first CBX, wish I had done my homework before buying, but everything I have read on this site and others about the CBX is true. First it's one sweet ride and definitely addictive, and this bike I am sure is far from perfect although I have never ridden another CBX to compare, and my only regret is that I had not discovered the CBX bike earlier in my career. Anyhow since purchasing I have had to flush the gas tank which was full of rust, clean the carbs, completely re-build all the brakes, the front still spongy and pulling to the handle even after pumping at least a liter and many attempts to get a good brake, my next step is to purchase new brake lines and keep my fingers crossed this will solve the problem,the back bled without problem. I recently had the carbs synched. The clutch makes the rattling noise at low rpm, so today I opened with the intention of sending it to TIMS to have it upgraded. Turns out this bike at sometime had already had the clutch basket changed to a 1981-82 basket. I confirmed this by sending a photo to TIM as what came out was not what I saw in the workshop manual. From my understanding this is a good thing as the 81-82 clutch baskets were much better design and eliminated the rattling sound, only I discovered that there were three hairline cracks in the inside base of the clutch outer.

Is this normal and something not to worry about as I would imagine if it did disintegrate while driving the engine would be wrecked. Tim's suggested that the cracks might be causing the rattle or maybe the carbs still not properly synced. Is there a way to see if the primary chain has been stretched, because with the the bike in gear when I turn the shaft which drives the clutch there is a lot of movement before actually moving the back wheel. Also the small chain which drives the oil pump had about 3/4 " of freeplay, is this acceptable and not a worry?

Just wandering if I could get some feedback on these issues.

Thx, Paul

[daves79x]

Paul:
First, welcome. Possibly a moderator will move your topic to the appropriate tech heading to get more exposure.

Anyway, front brake bleeding is a BIG problem on CBX's, from old master cylinders to air still in the lines, which I'm sure you still have. Lots of threads written here on the subject - see what a search turns up. I can specifically help, but am traveling right now - I'll monitor the forum but can't post much.

I suspect your carbs are not perfect yet - the clutch should be quiet if it is a late model and all else is well. Don't know about the cracks - something that can be welded?

Don't worry about the oil pump chain - they run way slack.

Gotta run but keep us posted. I'm sure others will chime in.

Dave

[steve murdoch icoa #5322]

Paul, i eliminated the spongy front brakes on my '81 when i got stainless lines and eliminated the splitter.
Just two long lines and a double banjo bolt at the reservoir made things easier to bleed.

[NobleHops]

Hey Paul, welcome.

I did indeed move the topic, but as you had several items I just settled on putting it in 'Project Threads'.

I had one of those ass-kickings with bleeding the front brakes, you are not alone. The rear is so easy it sets you up for massive frustration with the front, doesn't it?

I ended up doing what Steve suggested, and got a 2-line kit with a double banjo bolt at the MC, and it did make bleeding a lot faster and more effective. Site search is your friend, you will find several threads titled with some variant of 'brake bleeding' to peruse, but don't worry about asking questions, we like to help. You will see I resorted to desperate measures when you find my thread .

In short summary though:

Remove one caliper bolt and rotate the front calipers a bit so the bleed fitting is the high point.

Bleed each of the banjos, including the one at the master cylinder and the ones at the splitter, by cracking them slightly while you SLOWLY pump the MC and then close them back up before you release the brake lever.

Tap, tap, tap on the brake lines and the splitter to dislodge any bubbles. Unbolting the splitter so you can move it around to release any bubbles can help too.

Get a velcro or other strap and hold the brake lever about halfway in, till the larger of the two holes in the MC is open to the fluid reservoir, close the MC back up, tilt the bars to make the MC the highest point, and tap tap tap all the lines to see if you can get the bubbles to rise to the MC. Leave it in this position for a few days.

Sacrifice a goat.

Good luck, and welcome!

N.