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 Dominick Your Own Question
Dominick
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
14379177
Type Your Boat Question Here...
Dominick is online now
A new question is answered every 9 seconds

My 1995 approx 700 cc standup Yamaha JetSki won't start

Customer Question

Hi
My 1995 approx 700 cc standup Yamaha JetSki won't start unless I pour petrol into the carb. Once it starts it runs perfectly apart from not idling which I will sort out later.
I want to know why it won't start on its own?
Submitted: 11 months ago.
Category: Boat
Expert:  RSRBOB replied 11 months ago.

Hi and thank you for your question.

This sounds like you have a slow speed circuit clogged in the carb. Water craft carbs have high speed and low speed circuits so since it runs normally at higher RPM's, this becomes the prime suspect.

I would suggest removing the carb and inspecting the low speed circuit. You can start by checking the setting for the low speed screw. It is the screw that is on the same side of the carb as the throttle cable. If it is set properly, then pull the diamond shaped steel plate off, remove the diaphragm, the "body1" which is like a half moon shaped piece of aluminum, and find the low speed jet under it. The low speed jet is the one that is physically in the lower of the 2 jets in the carb body.

Here is a link to a parts diagram that you can see what you are getting into:

http://partsfinder.onlinemicrofiche.com/riva_normal/showmodel.asp?Type=13&make=yamahapwc&a=34&b=4&c=0&d=1995%20SUPER%20JET%20700%20CARBURETOR

The Body 1 is reference #24 and the low speed jet is reference # 19, the low speed screw is reference #35. You are looking for any kind of physical restriction. Use contact cleaner to blow through the passages and make sure they are clear. You will want to remove the low speed screw to blow through that as well. Before you do remove it, turn it in until lightly seated and count the turns in and write it down. You will need to reset the screw later.

RSRBOB

Customer: replied 11 months ago.
Thanks for your answer but you took to long to respond
I fixed it on Saturday not long after I posted the question