Hello Squadra, Manuel from Milano (IT) on Kramit 50 Cross early 80's

[Manuel Kramit]

Happy to have joined this community, i am looking for help for restauration of a Kramit 50 cross early 80's. My first objective is to describe the moto as much as possible, since document book of moto is not available, the only picture i have is here attached.
The motor is a 50cc Minarelli MCS P6R 0M, excursion 42 mm;
The termic group is: an original(not modified) Minarelli 54 , Gilardoni 3 cilinder, in alluminium Nichel Silicium internal surface treatment , with 2 lateral inlets, diameter 38,8 mm.
The piston is an Asso-Werke numbered 1803 of 38,75 mm with a 2 seger rings (one L shaped height 2 mm and one of 1 mm height with square section ) ; flat head, 28 mm compression, 12mm diameter of the connection.
the two metallic rings once mounted in place on piston in the cilinder run on the sides of the exhaust hole.


My first need of help is the following:
i would like to change piston and metallic rings, with new ones does enybody know the codes of this Minarelli parts? Any suggestion on where to buy them online?
thank you all, Manuel

[gitane-mais]

Hi and welcome on S.R.C.F

For your piston, in France you can find it here :

http://www.cyclocollection.fr/index.php ... testi-new-

You can also see on eBay or http://www.50gpspecialparts.com/

A pics of your bike ?

[Manuel Kramit]

First of all: some important news about documents, found by my family today after a deep search in the old house where the moto was kept:
__________________________________________
Frame number: 00650
Model: Kram-it MKS. 50
CC: 49.9cc
Date of document: May 1985
Motor: Minarelli P8 (or 6 not clear :mick) C.S.A
___________________________________________

second: while waiting to provide a live picture i have found a valid reference picture of a very similar model (internet search helped me find a picture), even if with differences in some components(brakes, circular rear transmission disk), i'll post detailed pictures of the real motorbike as soon as possible.



third: thank you Gitane-Mais for the suggestions, very precious links! , that piston could work , maybe, my doubts are still present, i'll try to explain better:
The story of the bike as far as i remember is that it was used by previous owner for cross training/ junior competitions, it was then bougt used by my family in 90's after being reconverted to be used on road by a (good) mechanic (no more alive) and i am not shure if that is the original and correct piston or some spare part he had, (the engine so remade worked very well anyway i remember) so i'd like to find some reference in minarelli manuals about the suggetsed cilinder&piston combination for my termic group, so that i can use the codes of the manuals/catalogs to perform a web search for the parts. In other words i am afraid to choose wrong because there where many different models of pistons 38.8 and even with the same dimensional parameters, mine is shorter on one side for example (46.4mm on one side against 49mm). so my question actually is How to find the Minarelli catalog codes of the Asso 1803 piston?
i attach the Asso codes i have found correspondance for reference:


her more zoomed:

and the dimensions:

thank you

[gitane-mais]

1803 I think.
It would be better to wait to have the piston in hands to buy one.
The cylinder can have four transfers and the piston will have one.
Are you sure that the engine is not Corsa Corta (40.3x39) ?

[Manuel Kramit]

Yes my piston is numbered 1803 under the shell, and a similar piston will surely work.
by a web search and usin the table of my previous message it is an Asso 2845 (shell 1803), also the fact that on the inlet side it is shorter corresponds :


so i am pretty shure now that , if i want to replace mine i have to find an ASSO-Werke 2845 with shell number 1803.
my question is: what minarelli code, which tipically is 7 dicit (ex. 710XXXX ) corresponds to it? <--that's the question! :rolleyes: :quoi:. , can anybody with a minarelli catalog help me?
and if possible identify also the minarelli code for the segments only? (example 7108XX-X)

to Gitane-Mais question:
No, unfortunately i am afraid not a corsa corta ,because..I have measured the excursion, it is 42mm,and this corresponds to a standard 38.8x42 standard 49.9 cc Minarelli. I have not opened the block to see the mechanics and measure them, just removed the termic group after measure it's excursion with a caliber, from top of the PMS (top position of piston to PMI (lowest point of piston), and anyway my block has no oil chamber micro vent.it is a P6 standard as far as it seems then, the only particular thing i found is the "biella" (sorry italian word , don't know the english word) has 3 small holes on the top connection, for lubrification, bright copper colour.
i am wondering if in origin my motorbike was sold by KRAM-IT with a corsa corta just as in the picture i have found on the internet, maybe some expert of KRAM-IT can help understand better these series and their history.
I will take more pictures this weekend, for the moment i can attach another picture of the codes on the carter:

and some others of the Kramit MKS 50 er:










here follow the M.C.S Minarelli patented system:





and here follows the inner cylinder and details of the inlets of the Minarelli 54 Radiale Competizione 'Gilardoni 3' serie:

[gitane-mais]

Seen the year of the motorcycle, your engine can be the good one.

It is what you look for?





This one may be too old :/

[Manuel Kramit]

Hi Gitane-Mais, thank you for the answer, i've tried but ..no that does not help for the piston identification : if i search on the web according to your picture of the exploded scheme and part list but :rolleyes:i cannot find that piston code anywhere.
i have now some photos of the piston shape and of the motor termic group,
here they are, sorry for the poor quality:

[Manuel Kramit]

About the segments your link was usefull but raised a doubt:
in fact , in Gpspecialparts website ( http://www.50gpspecialparts.com/1/38_8m ... 73858.html) i have found two possibilities.. CROMED or NON CROMED segments..
i need to understand if the segments for NIKASIL cylinder (nikel slicicium trated alluminium cilinder) must be cromed or standard, :hein: any suggestion?

[Pépé minot]

http://www.scafutopistoni.it/index.php? ... oni&id=930

E probabilmente quello

Mancha altezza di compressione sulla tua foto

Per cilindro cromato

[Manuel Kramit]

Ciao Pepè, piacere di averti coinvolto,
the complete dimensional piston data are described in my first post on top!
anyway that seem to be matching. and it really looks like the ASSO 2845 .. what can be then the difference in betyween these two models? the material? Any idea of the Minarelli code for the one you suggest?
thank you all

[Manuel Kramit]

i have tried registering on the Scafuto web site but does not seem to work.. , i'll try to contact them.
In the while if anybody can help me with the corresponding Minarelli codes for the complete piston kit, i could look for it on the web..
i do not have any catalog or reference where to find those part/mark codes thank you