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Discussion Starter · #1 ·
Picked up my head & bore yesterday. Valves and seats are MUCH nicer now. They surfaced the head as well, as it had some nicks in it. (Wasn't me - honest)

I asked them to hone the bores as well, because I was installing new rings. They didn't do it because they reckoned that the bores are plated, and you can't hone plated bores.

I ran my finger down the side of one bore, and it was definitely smoother on the part where the rings have been running.

The thing is, how are my new rings going to bed into the bore surface, if it's already smooth?

AND

can you really NOT hone a plated bore?
(It was definitely honed when first assembled - I can see & feel the marks)
 
G

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Morning Friend (or evening were you are)

I had a 2 stroke 125 years ago (not that many) think it was a kawasaki kdx or may be a honda mtx trail bike that had some sort of coated bore. When the motor got a bit rattly i put new rings and little end in and sent the barrel off to be hone'd or rebored if needed. It came back with a letter saying the barrel was coated and could not be touched. Apperantly the rings should wear out not the bore.... YA RITE..
They told me not to be to gentle when i run it in or it would cause glazing so i rung its neck out (ha ha)
I think wot they ment was resonable accelerating but not to much high revs. this in theory loads the motor up bedding rings in and prevents glaze. Used to run all my new/rebuilt motor x bikes in this way but much more harshly.
It did run fine but i don't like the idea.
 

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Hi Folks

so if it is possible to hone a coated bore bases on the thickness of the coating....

there are several Engines you can, and a lot you can not, for example Moto Morini no way.
if you can work with a flexhone Tool with glass perls and you act real carefull
it is possible, we overhauled some engines that way and they work for more than 10Tkm now without a problem.

recoating?!? we tried it one time, problem is not the new coat, first it has to be decoated and that is hell for the aluminium with that cylinder we hade big probs to get it leakproof at the cylinderground and head gasket.
while decoating some elements of the alloy diffuses and you get hundrets of little holes a lot of too deep to plan it after coating.
so if you decide for a recoating pay attention to the surface.

after working now four years with a lot of benelli engines we decide to go another way to eliminate these problems.
a overhauled cylinder from us can be honed more than two times, it never has to be recoated and you can use pistons in 88mm or 90 or 91,5 diameter ;-))

ciao Alex
 

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Discussion Starter · #6 ·
I washed the bores in hot soapy water with a Scotchbrite scouring pad. That removed the general slipperiness. There must have been some kind of deposit in the bore surface to make it slippery. It's still shinier than the bottom of the bore where the rings don't travel, but, with luck, there'll be enough for the rings to grab onto, to bed into.

Waiting on new shims to arrive today, so that I can set the gaps again after the re-grind.

In the mean time, the forks are getting new oil, and the brakes new fluid. The rear wheel has a new sprocket, and the old chain has been removed. I may even re-grease the head stem bearings. She'll be a new bike again for a trip to SA - next week, then PI at the end of Feb.
 

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Discussion Starter · #7 · (Edited)
Shims arrived & installed, but a cap bolt chewed out it's mating thread as I was torquing it up. :mad: I knew a couple were weak. I've been only taking them to 11 Nm the last couple of times. Should be 13 Nm.
Now I'll be installing thread inserts on all 12. This would be almost impossible to do while the engine is mounted.
Not long now - I hope - unless something else goes belly up :(
 

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Discussion Starter · #8 · (Edited)
The saga continues

Was just about to close her up when I thought I'd see how much slop the springs in the back of the clutch had. I grabbed the clutch and rotated it. Damn thing rotated sideways!:confused:
Don't remember it doing that before, so I removed the clutch plates and spun the inner, to be greeted by a grinding noise :doh:
Removed the clutch completely, and discovered that the needle rollers had been worn flat. They are supposed to only roll when stationary, in gear & with the clutch disengaged.
Fortunately, it's a standard needle cage (KT40x47x18), and replacements will arrive early tomorrow. Surprisingly, only about $20 each. Thank God for small mercies. :clap:
 

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Hi,im not sure what clutch you have fitted ? but you may not be aware the new baskets are different, from what you say the needle roller is a slide fit over the shaft and then clutch basket slides over the outside. The original basket and also my new 07 basket on RS(same used on tre now) has the needle roller press fit into the basket.
Also if the aluminum basket can rotate in relation to the gear without pushing against the shock springs then the springs may be loose in there housings.
Have you looked at the pics of my knackered clutch ?
Good that you found things so you can fix,hope its all done soon (dont rush!) I cant wait to here a recording of the new exhaust if possible ?
ps.. if you have the basket off there is a casting with the year on it.
pps.. did you do your alter shaft and gear ?
ppps. can you update your site with new clutch for my RS
colin..
 

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Discussion Starter · #10 ·
Hi,im not sure what clutch you have fitted ? but you may not be aware the new baskets are different, from what you say the needle roller is a slide fit over the shaft and then clutch basket slides over the outside. The original basket and also my new 07 basket on RS(same used on tre now) has the needle roller press fit into the basket.
The inner race slides over the gearbox shaft. The roller bearings & cage slide over that, and the basket - including the outer race - slides over that. I'm assuming that the input shaft nut, when tight, holds the inner race from rotating.

Also if the aluminum basket can rotate in relation to the gear without pushing against the shock springs then the springs may be loose in there housings.
With effort, the basket moves about 2mm at it's circumference, before the first spring starts to work. So the spring can move laterally 2mm, but most movement is sideways (throwing out). I expect that sideways movement IS wearing the aluminium housing & is the source of the "rattles", but so far it's ok.

Have you looked at the pics of my knackered clutch ?
Yeah, it look like mine. Same '03' inside a circle.
I cant wait to here a recording of the new exhaust if possible ?
Just as soon as I can arrange it. I'm getting toey myself!

if you have the basket off there is a casting with the year on it.
There's an '03' inside a circle cast into it. I'm assuming 2003?


.. did you do your alter shaft and gear ?
Yep, it's the lastest.

Have you installed the latest?

can you update your site with new clutch for my RS
colin..
Will do.
 

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Yes the shaft and gear I have is the latest type. Your clutch then is like the pics in manuals,mine is slightly different with the needle roller press fit in the basket (you can just see rollers in pic in my gallery) my clutch if rotated moved about 10mm each way before springs engaged so your sounds ok.
by the way was your last outer plate set in the smaller castle ? mine originally was not,but it is now as per pics in manual and check of other bikes.
colin..
 

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Discussion Starter · #12 ·
.. was your last outer plate set in the smaller castle ? mine originally was not,but it is now as per pics in manual and check of other bikes.
I've had mine apart several times. The first time, the outer plate was in the offset position, and I re-assembled it in line. Since then though, I've been using the offset position, as it will (possibly) cause it to slip when the friction material wears down, saving the plates. Well, that's my theory :rolleyes:

My concern, though, is why would the rollers have flattened in the first place. They only come into play when in gear & the clutch disengaged, so really don't spend too much time rolling. Have they been crushed from pressure between the gearbox input shaft and alternator shaft? Has it anything to do with the new alternator shaft/Z25 gear? Is lubrication a problem? Was it just a weak bearing?
I'll be keeping an eye on it over the next 25,000 km.
 
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