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I dropped off my 500 crank last week for a re grind and I have two obstacles to overcome which I’m hoping the informed on this wonderful forum can help me with?

Firstly shells!
I’m trying to locate first undersized shells, yes I know original ones are like Rocking horse do da so I’ve been scouring for the 1955 - 60 Fiat 600/Multipla ones that I’ve read about on this forum that apparently fit. Does anyone know a source for these? I’ve located some on eBay in the US, they’re listed as -0.10” or 0.25mm for Fiat 600 model 100 with modified oil system 1955 - 60 but the picture only shows six shells when the engine is a four cylinder, I will be contacting the seller but I wondered if anyone here can shed any light also?

Secondly
Does anyone have a source for new con bolts or is it ok to re-use them ( I can hear sharp intakes of breath!) and if so what is the length and stretch limit ? The engineer said they looked over engineered and he would consider using them again if no other option was available, I’ve googled and hunted eBay for a set but to no avail so far, I suppose another option would be to look into having some made?

I’ll add that I’m fairly new to Morini ownership and this forum and that the machine shop was recommended by a respected member on this forum and that they had refurbished three 500 cranks in the past 18 months, so they know what they’re doing.
Any help would be much appreciated, over to you!

To confirm, it’s an early 500W model, 1980 (according to the log book) incidentally it has the number 17 scratched on to each engine casing, my wife laughed when hearing this as it’s apparently an unlucky number in Italian culture, when viewed as Roman Numeral XVII it is then changed anagrammatically to VIXI which in Latin translates to “ I Lived” implying “My Life is over” from Cicero’s famous announcement of an execution! We’ll see about that!

Best regards
Steve.

Second paragraph should read con rod bolts of course!

Steve.

Well I feel a bit sheepish, I contacted the seller of the Fiat shells and they were main bearings , hence only six, silly me but at least I know now !

Stevie B wrote: ↑29 Jun 2022 07:08
Secondly
Does anyone have a source for new con bolts or is it ok to re-use them ( I can hear sharp intakes of breath!) and if so what is the length and stretch limit ? The engineer said they looked over engineered and he would consider using them again if no other option was available, I’ve googled and hunted eBay for a set but to no avail so far, I suppose another option would be to look into having some made?

I always re-use the conrod-bolts because:
1. normally these bolts are loaded, strained to less than 20%-strength at stretch. In Dutch this is the "20%-rekgrenswaarde" but can't find the correct translation. there is no point in replacing a bolt which isn't deformed. they are in the same condition as ever, and have been tested a zillion miles in your bike.

2. new bolts are batch-production. they make 1 million (whatever number) in each production run but only a few are tested as a quality indication of the total batch. so you get new bolts in a non-tested condition.

what is safer, a used and not failed bolt or a new and not tested bolt.

regards Anne

I used to work at SWD in Zwolle (Stork Wartsila Diesel). the cylinderhead and connecting rod bolts were stretched by hydraulic press at 750 bar and then tightend. we never changed them, always re-used the same bolts over and over again. by use of hydraulics the bolt-stretch was always the same length.

I obtained big end half shells not long ago for my 1980 500Wfrom Mdina Italia, who only have second undersize at present when I looked. Try https://www.mdinaitalia.co.uk/M250321.html or search Mdina for "big end shells".
Fiona
owner of the "red rust heap 500"
Sydney Australia

Hi Anne

Thanks for your reply, what you say makes sense, the blue book says to never re use them, which is why I was asking.

Hi Fiona

Thanks also for your reply, I am aware of the 2nd oversize shells from Mdina but I want to avoid them if there’s any chance of getting 1st oversized shells, I might look into re lining the shells I have if that’s possible, rather than taking away a “life” of the crank.

Regards
Steve.

I believe Ariel square 4 shells (1000cc) might be worth investigating. The inner diameter of the big end eye is 1.5002-7 so same as the Morini 500 and the standard crank big end journal is 1.375”/34.925mm. They are easily available eg from Dragonfly.

Can I just say, the main reason I avoid more general motorcycle forums/fora and online advice is the prevalence of toxic neanderthal maleness, regardless of the required answer.

So, it is with barely-contained joy I see here we have regular and worthy contributions from Anne and Fiona. (Certainly not forgetting other female rider-owners.)

This doesn't cancel out those other humans but - at the very least - it proves that owning a Moto Morini is a cut above the rest.

Dom in NZ

Hi Daddy Dom,
Thanks for the compliment but to yours and others regret I’m a male morinist. And in no way offended as happens to easily these days.
My father is from Friesland where the boys carry names as: Anne, Hielke, Sietse, Tjitte, Piet, Jelle, Evert and Michiel. The girls have Anna, Anneke, Maaike, Nienke, Jetske, Grytsje and Sietske. All beautiful girls.

My first bike was (and still is) a BSA A65 which forced me to understand the engineer’s line of thought to ride it reliable. My second bike a Moto Guzzi LM, a bulletproof tractor. The latest bike a Morini 500.

Regards Anne

Very interesting, Anne. That means Fiona is in a class of her own, I knew this already!
DD

That’s great info VSB! I’ve had a look at Draganfly’s website , looks promising, I’ll definitely be pursuing that, could be a game changer, I’ll let you know how I get on.
Apologies for not replying earlier btw, life getting in the way!
Regards
Steve.