I tried to send 100,000 AMS to make an another masternode from my Wallet but it displayed " transaction too large" and If I send a amount about 6,000 AMS the it's ok. what's the issue?
Its probably because you have lots of small outputs* from staking or masternode rewards. Transaction and blocks are limited to what size they can handle. The outputs* that you try to combine as input** for your new transaction exceeds the transaction size limit. Under the hood its writing out huge arrays of outputs that will point to an input for your transaction, but after serializing your transaction it exceeds the transaction size limit, resulting in the message "Transaction too large".
My advice is to send smaller amounts (like you say, 6000 will work) and then combine (hint: coin control checkboxes) them again until you have merged them completely. Just a few entries in coin control with larger outputs as result.
* An output is an amount that was sent (via a standard transaction) to a AmsterdamCoin address, along with a set of rules to unlock the output amount. In blockchain parlance an output is called an “unspent transaction output”, or UTXO
** A transaction typically references previous transaction outputs as new transaction inputs and dedicates all input AmsterdamCoin values to new outputs.
