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Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 14780
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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I have a 2002 115 Yamaha four stroke feel injection with

Customer Question

I have a 2002 115 Yamaha four stroke feel injection with 230 hours on it. It starts and idols just fine but when I run it on the water I get about an 1/2 a mile or so running great then the motor bog out (the rpms falls to about 2000 like a choke has been put on). Turn off the key restart the motor and it will run again for another 1/2 mile then bog down again. I have changed out the mechanical fuel pump electric fuel pump. A fue days a go I removed the the water and fuel separator and put in an in-line gas line filter. The Motor ran great for about five hours just like new then it started over again.
It has been to a Yamaha mechanic and hooked up to a code reader they said no bad codes but they changed out the water pump and the thermostat Can you help me out
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.
Hello my name is ***** ***** whom am I speaking with?
Your symptoms are that of fuel starvation. Do you have another fuel tank, like a portable, that you can run the engine off of?
Customer: replied 1 year ago.
I have done that. Same things.
Expert:  Jason replied 1 year ago.
Have you tried squeezing the primer bulb over and over to force fuel to the engine. If you have, can you actually feel fuel go through it with each pump?
Customer: replied 1 year ago.
Yes no luck
Expert:  Jason replied 1 year ago.
What is the model number on this engine?
Customer: replied 1 year ago.
Are you as baffled as I am
Customer: replied 1 year ago.
Where can I find it
Expert:  Jason replied 1 year ago.
Baffled, no not at all. It's just a process of narrowing things down until you find the issue.
Do you happen to have the model number on the engine?
Have you checked fuel pressure while the engine is running? (and duplicating the problem)
The model number is ***** a sticker on the clamp bracket. It will start with f115 and have more letters after it.
Customer: replied 1 year ago.
Sorry to be so long have to go our side
Customer: replied 1 year ago.
This is a photo of the plat on the side of her
Customer: replied 1 year ago.
I have no way of checking the fuel pressure that's why I change the two pumps
Customer: replied 1 year ago.
F115TLRA
Expert:  Jason replied 1 year ago.
Got it.
You said you changed the electric fuel pump. Did you change the actual injection pump? This would be inside the vapor tank. And it would have been a lot of work to get to it. The intake manifold would have had to come off just to get at the vapor tank. It would have been a few hours of labor.
Customer: replied 1 year ago.
Yep did that I changed thet pump I had to take the breather off the intake manifold and remove the old pump and put in a new one. I also chand out the mechanical fuel pump bolted on the outside of the motor
Customer: replied 1 year ago.
What's dumping me is that when I removed the fuel separator and put in a in-line filter it ran great for several hours then started over again
Expert:  Jason replied 1 year ago.
Does your alarm system work on the engine? If you pull the lanyard off, and try to start it, will it beep letting you know it works?
Customer: replied 1 year ago.
Never tried that what will that tell me
Expert:  Jason replied 1 year ago.
It will tell you if your alarm system works. If it's not working you could have an overheating or low oil pressure issue, (or related sensor issue) and not know it if the alarm system does not work. Can you check that and get back to me, or what works best for you?
Customer: replied 1 year ago.
Will try it now
Expert:  Jason replied 1 year ago.
Okay
Customer: replied 1 year ago.
Nothing beeps motor just turns over but no start
Customer: replied 1 year ago.
It was I on a code reader at Riverside Yamaha in Edmonton they said no fault codes
Customer: replied 1 year ago.
What now
Expert:  Jason replied 1 year ago.
So no alarm system, got it.
Here is what needs to happen. The boat needs to go out in water and the problem needs to be duplicated with a fuel pressure gauge hooked up to it. If pressure drop when rpms drop, then there is a fuel pressure issue, and that needs to be found.
If fuel pressure remains good (43 psi or so) then what is happeneing is the engine is dropping spark to the cylinders. The next step is to use a timing light and figure out which cylinders are dropping spark. Once you know which are dropping spark, then you can work on why it is dropping spark.
Regardless of who is going to do it, this is what needs to be done. Is this something you can handle?
Customer: replied 1 year ago.
First I have to order a fuel pressure gauge and a timing light
Customer: replied 1 year ago.
I live in a remote area good mechanics with proper equipment are find
Expert:  Jason replied 1 year ago.
Okay let me know when you are ready. There are no time limits here so post back at any time.--Jason
Customer: replied 1 year ago.
Hi Jason how is it going I just noticed that there is a air bubble forming in my inline fuel filter. This is after I removed the water separator and installed in-line filter because there was air bubbles forming in the separator Now I have switched to exterior tank, changed the fuels line up to the filter, new mechanical pump, new electrical pump. Why would that air bubble form in the filter. Would the problem be before the filter or after the filter
Expert:  Jason replied 1 year ago.
When running it is normal to see a little bit of air in that filter. (Not a lot, but a little). If it was so much that it was actually causing an issue then pumping the primer bulb over and over, which you did, would allow the engine to pick up rpms. So that is normal.
Customer: replied 1 year ago.
Ok it's about 1/3 of the filter. but I have a code reader and cables coming when they get there I don't know. This is getting very annoying to me. Call Yamaha they're not much help
Expert:  Jason replied 1 year ago.
See what happens after you check fuel pressure and spark.
Customer: replied 1 year ago.
Question I have access to an automotive fuel pressure gauge Ford, GMC is there a fitting I could get to convert it to a Yamaha
Expert:  Jason replied 1 year ago.
This is getting to be to much. I'm going to opt out and call it quits. If somebody else wants to take over they can. Good luck.

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