Benelli Forum banner
1 - 20 of 76 Posts

·
Registered
Joined
·
121 Posts
Discussion Starter · #1 ·
Hi... well after all the chain of worn items where replaced, looks i'm facing the last link: the starter clutch.

All looked very very good, but the thing started to slip now... long story short, it should be the last thing of the bike that was abused

On topic, what (in order) needs to be removed to get that starter cluch changed?

If there are some pics of the process it could be very good.

So far I know
1) clutch, then gearbox
2) keep the gearbox in 4th so removing and getting it back do not destroy the neutral sensor

but... what more? where is the starter clutch actually?
 

·
Registered
Joined
·
947 Posts
The starter clutch sits above the gear cluster and is removed through the hole remaining after the cluster is removed. Main clutch needs to come off and alternator so z25 gear and shaft can pull out as this holds the starter clutch in position. I would remove in this order
Alternator
Z25 bolt
Clutch
Gearbox in 4th gear
Z25 shaft
Starter clutch
Any one correct me if I have missed something!
 

·
Registered
Joined
·
189 Posts
The starter clutch sits above the gear cluster and is removed through the hole remaining after the cluster is removed. Main clutch needs to come off and alternator so z25 gear and shaft can pull out as this holds the starter clutch in position. I would remove in this order
Alternator
Z25 bolt
Clutch
Gearbox in 4th gear
Z25 shaft
Starter clutch
Any one correct me if I have missed something!
Only the small lube pipe which has to be withdrawn from clutch side and retained by the bearing retainer plate. Nigel.
 

·
Registered
Joined
·
186 Posts
Not a particularly difficult job. Just one terrible mistake I have seen - if the Z25 shaft is tight and will not press out by hand, do not force it against the crankcase casting. That could break the shoulder that locates the ball bearing. The shoulder prevents the Z25 shaft drifting across and contacting the clutch. The safest way to get the Z25 shaft out is to put a bit of 5mm screwed rod through it. Screw a nut on the coupling end and slip a bit of tube over the other end of the shaft, bearing against the Z25 gear. A big thick washer & a nut go over the screwed rod, against the tube, to pull the shaft out as the nut is screwed inwards. (Feed a 3/8" socket extension, 12mm bolt or bar in as the Z25 shaft is withdrawn, to prevent the starter drive falling.) That way the reaction force goes through the various components that sit on the shaft and will not load-up that weak little shoulder. If the screwed bar & nuts cannot achieve enough force to pull the shaft out you are in dangerous territory. If retaining compound prevents the coupling coming off the Z25 shaft, heat the coupling (250 degrees C) to weaken the compound. If all else fails, as can happen if the shaft is twisted, you might be forced to remove the threaded rod and use a very heavy hammer held hard against the tube over the gear end by a strong, reliable assistant, as you use a drift and hammer to knock the shaft out. The drift must be carefully centred in the shaft so that it does not contact the coupling or bearing and break that shoulder. The assistant must have the hammer deliberately pressed hard against that tube for every blow.
 

·
Registered
Joined
·
81 Posts
Not a particularly difficult job. Just one terrible mistake I have seen - if the Z25 shaft is tight and will not press out by hand, do not force it against the crankcase casting. That could break the shoulder that locates the ball bearing. The shoulder prevents the Z25 shaft drifting across and contacting the clutch. The safest way to get the Z25 shaft out is to put a bit of 5mm screwed rod through it. Screw a nut on the coupling end and slip a bit of tube over the other end of the shaft, bearing against the Z25 gear. A big thick washer & a nut go over the screwed rod, against the tube, to pull the shaft out as the nut is screwed inwards. (Feed a 3/8" socket extension, 12mm bolt or bar in as the Z25 shaft is withdrawn, to prevent the starter drive falling.) That way the reaction force goes through the various components that sit on the shaft and will not load-up that weak little shoulder. If the screwed bar & nuts cannot achieve enough force to pull the shaft out you are in dangerous territory. If retaining compound prevents the coupling coming off the Z25 shaft, heat the coupling (250 degrees C) to weaken the compound. If all else fails, as can happen if the shaft is twisted, you might be forced to remove the threaded rod and use a very heavy hammer held hard against the tube over the gear end by a strong, reliable assistant, as you use a drift and hammer to knock the shaft out. The drift must be carefully centred in the shaft so that it does not contact the coupling or bearing and break that shoulder. The assistant must have the hammer deliberately pressed hard against that tube for every blow.
Very well - where on the picture is the starter clutch one way bearing located ?
 

·
Senior Member
Joined
·
6,093 Posts
if the shaft is twisted, you might be forced to remove the threaded rod and use a very heavy hammer held hard against the tube over the gear end by a strong, reliable assistant, as you use a drift and hammer to knock the shaft out. The drift must be carefully centred in the shaft so that it does not contact the coupling or bearing and break that shoulder. The assistant must have the hammer deliberately pressed hard against that tube for every blow.
Or do what Cam was forced to do because his was so very badly twisted, and grind the shoulder out of the drive shaft to release the Z25 gear from the shaft. Nasty, but it worked. Cam showed me the shaft and gear a couple weeks ago. Job well done.

Good thinking on the "pulling the shaft out" idea.🙏
The latest two shaft designs have a 5.0 mm hole through them, so an M5 threaded rod will fit. I have an original shaft with a M8 thread holding the coupling in place - as opposed to an M10 thread - and this shaft appears to have an M5 thread at the gear end, so an M5 bolt at that end may suffice.
after I remove a headless clutch cover bolt that's been ground away from a nasty slide down the road.
 

·
Registered
Joined
·
186 Posts
Very well - where on the picture is the starter clutch one way bearing located ?
This is a better picture looking into the top half of the crank case from below. You should have copies of the various Tre workshop and parts manuals as references. I can help you with that if necessary but not till after Easter as I have guests to entertain and a 600km ride tomorrow.
Automotive tire Motor vehicle Machine tool Automotive design Vehicle
 

·
Super Moderator
Joined
·
7,860 Posts
I emailed maniac motors for the part which they have but they said I should be changing Z60 and the "flansch" too is that correct ?
[/QUOTE]
Yes, that is correct.
Gear Bicycle part Tool Rim Font


Camera lens Camera accessory Auto part Cylinder Machine
 

·
Registered
Joined
·
81 Posts
I emailed maniac motors for the part which they have but they said I should be changing Z60 and the "flansch" too is that correct ?
Yes, that is correct.
View attachment 37784

View attachment 37782
[/QUOTE]
Thanks everyone you are very good indeed. Hopefully I will get it done without too much trouble. Another question what about the water pump will that be in the way and do I have to drain it ?
 

·
Super Moderator
Joined
·
7,860 Posts
Another question what about the water pump will that be in the way and do I have to drain it ?
No, there is no need to remove or drain the coolant. You just need to pull the large rubber hose out of the way to remove the alternator.
Automotive fuel system Motor vehicle Light Vehicle Automotive tire
 
  • Like
Reactions: millgolfhouse
1 - 20 of 76 Posts
Top