9 risposte a questa discussione

[madbunny]

this is friend's mito cylinder output view.
full overhauling 2month ago. piston,crank,cylinder,bearing.
oil use motul synth 100%. fullness preheating before riding.
but problem came by the middle of domesticate.
milage just 2000km. (almost brand new condition. you can see the clean exhaust port!)




73037 nikasil coat cracked.
can see the port's coat crack & bubble scar.


now i use 66650E. I had same problem at used 73037 too.
similar crack at that time.
this scars hard to stick oil layer.
and it will be sculpture depth at piston.

i think that's not user fault. maybe 73037 has defects. how do you think?

[marco 2t]

perhaps you have wrong coupling cylinder-piston during overhauling

Messaggio modificato da marco 2t il 18 November 2009 - 13:14

[Nitrus]

I suppose that a product built up by engineers and in production not so many years ago can't be defective....the nikasil crack has a lot of reasons...maybe as marco 2t said your friend chose a bad coupling...maybe the carburation wasn't so good....there are too much reasons...wich carburator does the engine work with?how the carburation is?the coupling you and your friend chose?what kind of piston you used to have with 73037?

[madbunny]

hi nitrus, he use C type cagiva genuine piston.
no carbueration change. all units are normal. just mito EV 2000year model stock condition.

Messaggio modificato da madbunny il 21 November 2009 - 17:29

[Nitrus]

a C type???this isn't the kind of piston......for example I use an "Asso Werke"...I have a 34vhsb as carburator..the carburation must be a little bit rich for engine health.....how about you?

[{mRk}]

Nitrus, il Nov 21 2009, 05:33 PM, ha scritto:

a C type???this isn't the kind of piston......for example I use an "Asso Werke"...I have a 34vhsb as carburator..the carburation must be a little bit rich for engine health.....how about you?

Utilizza un pistone Asso, "C" è la classe dimensionale. Dovrebbe corrispondere ad un 55,97mm.

madbunny, il Nov 21 2009, 05:27 PM, ha scritto:

hi nitrus, he use C type cagiva genuine piston.
no carbueration change. all units are normal. just mito EV 2000year model stock condition.

What is the measured diameter of the cylinder?

Messaggio modificato da {mRk} il 21 November 2009 - 18:30

[Nitrus]

giusto....ho pensato che un pistone di tipo c non aveva senso...e invece........calcolando che il diametro del cilindro è 56 mm e spiccioli con quella misura credo che sia stato bello largo....vediamo cosa dice di altro....

[madbunny]

C type cagiva genuine piston =>
cagiva originale pistone 55.98mm dimensione.

I don't have Bore vernier caliper.
so i don't know how cylinder diameter is.

[mitico92]

madbunny, il Nov 22 2009, 05:26 AM, ha scritto:

C type cagiva genuine piston =>
cagiva originale pistone 55.98mm dimensione.

I don't have Bore vernier caliper.
so i don't know how cylinder diameter is.

that's probably the problem.
you have to know the diameter before you buy the piston.
probably your piston was not suitable for your cylinder

[amz69]

ma una roba del genere è recuperabile con una ricromatura?

non si vede dalla foto se la spaccatura sia giunta anche sul cilindro vero e proprio, se cosi fosse, il cilindro non è più recuperabile vero?