CLUTCH woes

Message

plasticpig72 · #1 Post by **plasticpig72** » Sun Jul 21, 2013 8:25 pm

April and I have only been together since last October and due to the fact that her previous owner was an idiot who owned his own bike repair dealership and should not have been trusted to repair a skateboard let alone anything with an engine.

Gradually I have been resolving the issues, but progress was slowed when neighbours lad reversed into April and knocked her over.

One of the remaining issues is this damned clutch.

The issue:

When the bike is cold you can't engage neutral, a common problem I understand. It rattles in neutral until you pull the clutch in (suspect thrust bearing). But the biggest issue is, when you have done 50 miles or so of motorway riding, it doesn't work at all. You have to pump it frantically to get some life back into it. If I bleed it then I get several days out of it before the problem reoccurs on a run, but if I use the bike round town it never appears.

Sounds like it is getting air in and I would accept that, but having refused to work tonight, I will get on it tomorrow and it will be fine. Furthermore the fluid level is not changing.

I confess that I am baffled.

Suggestions please.

Aladinsaneuk · #2 Post by **Aladinsaneuk** » Sun Jul 21, 2013 8:29 pm

Start with the clutch jet - sorts neutral selection out

Then change the clutch line - and add a bleed nipple at the top :)

I suspect the clutch slave seal may be shafted - either new seals or a motopike / Oberon replacement

zoidberg · #3 Post by **zoidberg** » Sun Jul 21, 2013 9:22 pm

Mine rattles a little when in neutral and clutch out. Most of my bikes have done that tbh.

Dalemac · #4 Post by **Dalemac** » Sun Jul 21, 2013 10:49 pm

Issue 1 - Common problem, replace the clutch jet for a bigger one.

Issue 2 - Not an issue, there is notable change in the engine noise when the clutch is engaged/disengaged.

Issue 3 - As already stated, probably a leaky clutch seal.

Falcopops · #5 Post by **Falcopops** » Mon Jul 22, 2013 12:22 am

If it was the clutch seal surely there would be a noticeable drop in fluid level, but this doesn't seem to be the case.

I suppose on the motorway you're not using the clutch much, but round town you are. I was thinking along the lines of master cylinder seals, but that wouldn't make sense as it shouldn't change the more or less you use the clutch.

Could it be a heat issue? if the bike is getting hotter round town it may be related to the length of the actuating rod, but at startup from cold it would be at it's shortest.

Not finding a solution, but hopefully it'll prompt a bit of alternative thinking.

I do think you should cover all the other basics mentioned so you can eliminate potential problems that should eventually either cure the problem or reveal the culprit.

Oh one last thought, the actuating pin at the lever, there should be a little slack before it engages the master cylinder. Again I seriously doubt this is the source of your problem, just another thing to check, look for the tiny locking pin and slacken before trying to adjust the actuating pin.

D-Rider · #6 Post by **D-Rider** » Mon Jul 22, 2013 12:42 am

Dalemac wrote:Issue 1 - Common problem, replace the clutch jet for a bigger one.

NO - Don't do that - it's a SMALLER one.

The first Falcos had a 75 jet, the later ones were improved a bit with a 60 but the better result is with fitting a 40 - as per what was fitted to the Gen II RSVR.

There are other things that affect ease of neutral selection - such as drive chain tension and throttle body balance.
Since fitting my Gabro chip I've also noticed that neutral selection is remarkably better (something I had not anticipated at all)

Certainly seems that you need to double check your clutch actuation system for leaks - and as Pete has mentioned (and it took long enough to convince him to try this) fitting a banjo bolt with a bleed nipple at the clutch master makes bleeding so much easier and more effective,

control_67 · #7 Post by **control_67** » Mon Jul 22, 2013 1:16 am

Sounds similar to when my clutch slave failed, there was no noticeable drop in fluid then either, just a complete loss of pressure and no clutch. I replaced the slave with an Oberon and its been great for just over a year now.

fatboy · #8 Post by **fatboy** » Mon Jul 22, 2013 6:27 pm

You have a master and a slave on the clutch side, when one or the other cylinder gets a bit tired, the bores may become pitted because of corrosion from contaminated fluid,wearing the seals,dirty fluid also 'enlarges' seals, making them floppy and not fluid tight so when under pressure fluid can wash back over the seal rather than be forced into pushing a piston, hence no obvious fluid loss.
Slave is the prime suspect,replace makes more sense than repair, bleed point on banjo very good idea !

plasticpig72 · #9 Post by **plasticpig72** » Mon Jul 22, 2013 6:45 pm

Seal & silicone grease on order. Minimal cost so worth a go. I will do the Jet as well, again it's cheap enough.

The niggles of owning an older bike.

On the plus side, when she goes, god does she go and at those moments the grin wipes away all the niggles.

Thanks everyone for your help, I'll let you know how I get on.