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Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 15620
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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There Jason. JA: Thanks. Can you give me any more details

Customer Question

Hi there Jason.
JA: Thanks. Can you give me any more details about your issue?
Customer: Oops. I'll try again. Hi Jason my name is ***** ***** i'm having problems with my 40hp yamaha outboard, model 40VETOL (or 40TLRY on US market). I'm having issues with the engine surging at throttle positions above approx 60% and generally running rough and lacking responsiveness. Also, when flushing the engine on a hose there seems to be a lot of raw fuel coming through the prop with the cooling water even at idle. When i squeeze the primer bulb in the fuel line it never gets to the point of being completely hard, even to the point where the engine will hydraulic lock on unburnt fuel in the chamber. I realise this can only be caused by a float level issue but am unable to come up with a solution even after cleaning and re-kitting all 3 carbs and setting float levels as per Yamaha manual. Any help would be greatly appreciated.
JA: OK got it. Last thing — Marine Mechanics generally expect a deposit of about $26 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.
Hi Chris, Jason here. It sounds like the fuel pumps diaphragm has a pin hole in it. The fuel pump is driven by crankcase pulses, when they get holes in them what happens is when you pump the bulb it will push fuel through that hole directly into crankcase, which if pumped to much can flood the cylinder out with fuel. It also causes the engine to run rich all of the time. What you would want to do is rebuild/replace the fuel pump. Does that make sense?
Expert:  Jason replied 1 year ago.
I think that should do it. But I work for tips so I do want to make sure you are happy with my service before you go. If you had a further question on the issue by all means feel free to ask. If not, Just in case you do not understand the way the website works (and some folks do not). You do have to put forth a positive rating in order for it to credit me for helping you. When ratings are not done, the website simply keeps your deposit and they will not credit me. The ratings box is located at the top of the screen. To rate, you must select the star you wish and also confirm it. Please let me know if you run into any problems or errors when trying to do it. If you do have a problem, or if you can not see the ratings box which is at the top of the screen. Please reply back "I rate Jason's service _______" and fill in the blank.Questions do not close out, so if you have to come back later on with follow up questions to the issue you still can even after doing a rating.Thank youJason

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