Working on motor need help please

[Tommy89]

I have a 96 Yamaha 50hp 4 stroke and i want to make sure the engine still works bf I spend $1000 on a new drive assembly for the lower unite. Can I hook a hose up to the tube for the water pump and start the motor for 30 sec without screwing anything? I just want to know if it runs. Thank you

 

[rejesterd]

If you just want to know if it can run for a few seconds, you can run it without the water. The engine takes minutes before it gets hot enough to open the thermostat, so you should be fine. Just keep the lower unit removed while you do it.

But really, letting it start and idle for a few seconds won't tell you if it's worth fixing. If it were me, I would do a compression test. A cold compression test isn't as accurate, but it can still tell you if one cylinder is way off from the others or if they're all generally the same. If compression is decent, then it's probably worth fixing imo.

 

[Tommy89]

Ok I have a friend who has a compression kit. He's going to help me check the motor sometime in the next few days. Thank you

 

[ClassicAQ]

Running an outboard w/o a cooling system?!? No no. Guarantee the temp sensor will alarm within 30-45secs, less if you're located in FL or likewise 90° heat. Did the engine run before needing the drive assembly? If so, why do you need to run it.

 

[Tommy89]

It's been over a year or 2 since it was ran