How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Charles Your Own Question
Charles, Marine Mechanic
Category: Boat
Satisfied Customers: 3713
Experience:  US Navy (Ret) Certified Mercury Marine Tech with over a decade of repair experience.
Type Your Boat Question Here...
Charles is online now
A new question is answered every 9 seconds

I'm trying to learn how to do a compression check on a 1900

Customer Question

I'm trying to learn how to do a compression check on a 1900 Yamaha Waverunner - 500
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Tell me a bit more about what's going on so the Marine Mechanic can help you best.
Customer: The engine will turn over but will not start
JA: Is there anything else important you think the Marine Mechanic should know?
Customer: the engine compartment did take on some water because the rider was unaware the drain plug was loose. It did run a couple of times after the incident but was harder to start each time
Submitted: 1 year ago.
Category: Boat
Expert:  Charles replied 1 year ago.

Hello, my name is***** will assist you.

To do a compression test, remove the spark plugs, install the compression tester gauge into the spark plug hole. Crank the engine over until the gauge reaches max reading. Record that reading. Do the same for all remaining cylinders. You are wanting all cylinders to be with-in 15% of each other.

Related Boat Questions