Let me guess......You have it on a battery and with the control cabling and all, you turn the key and what you say happens. You turn the key off and back on and it repeats.......yes-no?
Read the prompts and archives about starting an engine that has been sitting for a long time. After that, ensure that you have a good battery, capable of delivering a 150 amp surge with 11 volts across the battery terminals. Then ensure your cabling between the battery and the engine is at least #4 AWG and no longer than 6'. Then ensure that all the connections between the engine and the battery are clean (inside) and tight. Then it wouldn't hurt to shoot some oil on the starter gear and the shaft that it rides on to ensure that it has minimum friction.
If what you read didn't specify it, you need a fresh fuel mix available for the engine with 1 pint of TC-W3 Marine 2 cycle oil to 6 gallons of unleaded regular gas, 89 octane preferred but 87 works ok.
You need to have water applied to that New water pump you put in as a result of your reading so you need muffs attached to the water pickups on the lower unit attached to your house water supply via garden hose.
Now, try it again. Good luck