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 Jeremy R. Your Own Question
Jeremy R.
Jeremy R., MarineTechnician
Category: Boat
Satisfied Customers: 9020
Experience:  Multiple factory certifications 20+ years of experience.
Type Your Boat Question Here...
Jeremy R. is online now
A new question is answered every 9 seconds

I have a 1999 Gp800 just rebuilt, the spark is good but the

Customer Question

I have a 1999 Gp800 just rebuilt, the spark is good but the engine still wont start. I have tried mixing oil and fuel into the cylinders to start, but no luck. Any help would be great.
Submitted: 2 years ago.
Category: Boat
Expert:  Jeremy R. replied 2 years ago.
Hi, 0My name is***** you for letting me try and assist you with your problem.
I know you said you just rebuilt it but you need to set up your basics.
Check compression, check spark.
You obviously have fuel.

What do the plugs look like?
Have you tried a new set and held the throttle wide open?

Let me know what you find.
Customer: replied 2 years ago.

Compression is good, spark is good, plugs have oil but not fuel. Yes have tried two sets of plugs and with throttle wide open.

Expert:  Jeremy R. replied 2 years ago.
Are you sure the reeds are sealing.
that will cause this problem
Customer: replied 2 years ago.

Havent tried that but how about a bad power valve?

Expert:  Jeremy R. replied 2 years ago.
It will make it hard to start but they don't go bad. They just can be open when they need to be closed.
Pop off a cover and make sure they're down all the way.
Customer: replied 2 years ago.

I will check that first. anything else I should look for while im disassembling the exhaust?

Expert:  Jeremy R. replied 2 years ago.
Nah there's nothing else functional to it as long as the gaskets are all inplace keeping water out where it's not supposed to be.