Varying slack in clutch lever

[ranton_rambler]

Has anyone encountered a phenomenon where the amount of slack which can be felt at the clutch lever varies? More slack on the overrun and less when the motor is driving. My 175 seems to have developed this.

I guess the helical gears in the primary drive must apply thrust in opposite directions under drive/overrun, and I thought the nut in the middle of the clutch must have come loose, letting the whole thing move on the gearbox input shaft. But having gone inside, the nut is tight. So is the whole shaft moving back and forth, and do I need to worry about it?

The gearbox shifts up and down nicely and doesn't appear to make any horrible noises.

Ian

[Bevel bob]

Does not sound right. Missing spacer ?spring studs can come loose. broken shim in side the case?

[themoudie]

Aye Ian,

I would agree with Bob, but cannot remote diagnose.

Having had a clutch spring post detach itself from the clutch hub and come through the side of the primary case at 60mph on the 450, which are known to be prone to this detachment, I would suggest opening up the primary drive side and as you investigate, dismantle the clutch, check for wear to the pushrod components, then the clutch components and any lateral end play on the input shaft, on which the clutch is mounted, couple of thou (0.002"), but any more wouldn't look good to me.

To cure the spring post problem, I had 6 sets of new increased diameter posts machine up and the hub re-drilled to accept the new posts that were then silver soldered into place. This involved pre-heating the whole assembly in an engineers oven and then applying the silver solder to the pre-fluxed joints, before leaving the whole assembly to cool naturally, so as not to weaken the hubs metallurgical structure. So far, no further detached posts trying to break loose.

My posts were made for the MKIII clutch hubs, so I am not sure if they would be suitable for 175 narrow case engine.

Apologies not to be more helpful and good health, BillR

[Duccout]

Hi Ian,

I don't want to be a prophet of doom, but the only way that I can see this happening is if the bearing behind the clutch is loose in the crankcase. I hope that I am wrong!

Cheers,

Colin

[Eldert]

Hi Ian

there should be a circlip on the shaft holding the cluch gear on the inputshaft . is that still in place ?

Regards Eldert

[ranton_rambler]

Aye Ian,

I would agree with Bob, but cannot remote diagnose.

Having had a clutch spring post detach itself from the clutch hub and come through the side of the primary case at 60mph on the 450, which are known to be prone to this detachment, I would suggest opening up the primary drive side and as you investigate, dismantle the clutch, check for wear to the pushrod components, then the clutch components and any lateral end play on the input shaft, on which the clutch is mounted, couple of thou (0.002"), but any more wouldn't look good to me.

To cure the spring post problem, I had 6 sets of new increased diameter posts machine up and the hub re-drilled to accept the new posts that were then silver soldered into place. This involved pre-heating the whole assembly in an engineers oven and then applying the silver solder to the pre-fluxed joints, before leaving the whole assembly to cool naturally, so as not to weaken the hubs metallurgical structure. So far, no further detached posts trying to break loose.

My posts were made for the MKIII clutch hubs, so I am not sure if they would be suitable for 175 narrow case engine.

Apologies not to be more helpful and good health, BillR

I pulled it apart yesterday and there are no issues with the posts in the hub and the big nut in the middle was still tight. I have heard of the posts detaching but have not experienced it myself.

[ranton_rambler]

Hi Ian

there should be a circlip on the shaft holding the cluch gear on the inputshaft . is that still in place ?

Regards Eldert

Eldert - the answer is that I don't know. When I took the plates out and checked the nut with my torque wrench it was all tight so I didn't dismantle any further. I drained the oil and there were no worrying pieces in the oil and nothing in the primary cover.

[blethermaskite]

Ian, I think you have already identified the issue in your first post.....you are almost certainly getting helical gear thrust effect through your clutch action, as you say the clutch centre nut is tight then its a logical step by step further investigation, I would be looking at the clutch basket bearings next.......can you 'feel' end float on the clutch assembly as you twist it either direction? Cheers George

[ranton_rambler]

I'm off out for lunch now but will ride the bike there and see if it gets worse when hot as has been suggested elsewhere.

Limited time to do much more before next trip which is to Blairgowrie next week.

[ranton_rambler]

I have put it all back together and ridden about 50 miles today. Seems a bit better but not completely gone. It is the same whether hot or cold as far as I can tell. For now I think I will keep riding it and see if it gets significantly worse. Scotland trip will involve 300+ miles riding, although I did 430 miles at the weekend and it was fine apart from this "feature."