yam f115 problems

[cobb3333]

Hi, I have f115 2000 model , when i bought it earlier this year i thought it was 2005.I took it to yamaha main dealer because it was running rough.He could not access any data , and informed me it was a 2000 model to my dismay.
He has checked fuel system cleaned filters cleaned and checked vst filter , checked compression, checked fuel pumps , fuel pressure at rail,injectors refurbished, spark good, still the problem persists.He has all but given up on it.Any help would apreciated as i am at a loss and the dealer would be quite happy for me to take it home as it is.

[yamahaOX66]

I would look at the model number on the plate. You can then look up (search on line) the model code for that year. If the model number comes up as a 2005, then someone swapped out the powerhead or ecu. If so its time to call the dealer.

I actually didn't know the f115 was out in 2000. Thought it was later on.

[cobb3333]

The engine has been at the dealers for over i month , he checked the serial number on the engine.I need some advice as to what to try next with the engine . The yamaha dealer cannot find a fault.I have my reservations as to his compitence.Has anyone had a similar problem ,could it be an electrical problem?. the engine starts easy, misfires ocasionally on tickover, wont rev over 3500 to 4000 under load sounds rough ,like it is off a cylinder .

[rodbolt17]

dude, I do this for a living and have for about 30 years.
its a stupidly simple speed density EFI system using a transistor switched 12V waste spark ign system.

rail pressure is about the most critical part of the fuel system yet the ECU does not monitor it.
to much pressure,more than 5 psi to much and it can run stupid.
to little pressure by as little 5 psi and it gets stupid again.

bad plug wires, poor connections in the harness, overcurrent draw from the ISC or the fuel pump.

that's why I start every service job with a spark test and a leakdown test.
takes less than 30 minutes and determines can the ign PRODUCING components work and can the engine cylinders be mechanically sealed.

from there I use the laptop to look at what the various sensors are telling the ECU.
then clean the fuel system.

you must understand what each sensor does, why it does it and what happens if a signal is incorrect or missing.

its why here in the states Yamaha started the master technician program.

[boscoe99]

The engine has been at the dealers for over i month , he checked the serial number on the engine.I need some advice as to what to try next with the engine . The yamaha dealer cannot find a fault.I have my reservations as to his compitence.Has anyone had a similar problem ,could it be an electrical problem?. the engine starts easy, misfires ocasionally on tickover, wont rev over 3500 to 4000 under load sounds rough ,like it is off a cylinder .

I feels your pain. But this is life.

Fixing a problem is the simple part. Finding the problem that needs to be fixed is the hard part. Maybe your mechanic has only risen to the level of being able to fix problems, once they are known.

I would try a different mechanic. Just like sometimes we have to go to different doctors, we have to take our stuff to different mechanics. Painful but necessary.

[cobb3333]

dude, I do this for a living and have for about 30 years.
its a stupidly simple speed density EFI system using a transistor switched 12V waste spark ign system.

rail pressure is about the most critical part of the fuel system yet the ECU does not monitor it.
to much pressure,more than 5 psi to much and it can run stupid.
to little pressure by as little 5 psi and it gets stupid again.

bad plug wires, poor connections in the harness, overcurrent draw from the ISC or the fuel pump.

that's why I start every service job with a spark test and a leakdown test.
takes less than 30 minutes and determines can the ign PRODUCING components work and can the engine cylinders be mechanically sealed.

from there I use the laptop to look at what the various sensors are telling the ECU.
then clean the fuel system.

you must understand what each sensor does, why it does it and what happens if a signal is incorrect or missing.

its why here in the states Yamaha started the master technician program.

Thanks for your advice . I wish i could fly you over to Scotland to fix my engine.The mechanics here need to go on a masters tec course in my opinion rather than second guessing the problem.

[rodbolt17]

it goes like this.
suck
squeeze
bang
blow
has since the mid 1800's.
technology has simply allowed a smaller package to be more efficient and make more power for less weight.
but the same 14.7/1 air to fuel(gasoline) ratio still exists over 100 years later.

first you make sure the engine can mechanically seal.
then you make sure the ign system is capable of making spark.
the rest gets rather easy.yes there is a bunch of wires and a mystery black box but it works well or its broke.
very simple.

all that stupid ECU does is look at inputs,then based on a simple truth table map it gives outputs.
that's all the ECU does all day long.
ECU failures are VERY rare and typically caused by another failing component.

[bajakeith]

bad ecu's

the ONLY ecu that I have had go south are on the FICHT'S !!

[cobb3333]

That's good to hear hopefully ecu is allright. I removed the boat from the dealer today, gave him £200 for not repairing my engine ,with no diagnoses to the problem.I paid him to have the injectors checked, he said they were tested and working fine.
When I got home I removed the injectors and removed the filter from one after being advised by another member to do so.The filter was dirty,not completely clogged.
I am going to send them to Yamaha for refurbishment.I wonder if the dealer ever had them out.

[madharchod]

listening to mates dosent solve problems ,they only increase your bills in buying or doing things you dont need to do ,when somebody says he has 30plus experience ,take heed of it as experience dosent come cheap there has been lot of trial and error methods used before some body became an expert like RODBOLT
cheers

[rodbolt17]

not much trial and error here.
I have been taking professional auto and marine courses since I was 15 years old. I am 51 now.

prior to that I grew up in my fathers salvage yard.
other than a 6 year stint setting up and programming CNC lathes and mills and a 6 year stint in the US navy's advanced electronics field this is the only work I have ever done.
no paper routes no fast food this is about it.
Yamaha wont fix/clean injectors.
I use Flagship marine in Punta Gorda FL.
fast reliable and not very expensive and I can call and talk to the tech dealing with my injectors or the HPDI pumps I send if nessasary.

[cobb3333]

not much trial and error here.
I have been taking professional auto and marine courses since I was 15 years old. I am 51 now.

prior to that I grew up in my fathers salvage yard.
other than a 6 year stint setting up and programming CNC lathes and mills and a 6 year stint in the US navy's advanced electronics field this is the only work I have ever done.
no paper routes no fast food this is about it.
Yamaha wont fix/clean injectors.
I use Flagship marine in Punta Gorda FL.
fast reliable and not very expensive and I can call and talk to the tech dealing with my injectors or the HPDI pumps I send if nessasary.

Yamaha must work different here in the UK .I sent my injectors to Yamaha motors Uk today to get refurbished .They have to be sent through Yamaha dealer,they don't deal direct with the public.

[boscoe99]

Yamaha must work different here in the UK .I sent my injectors to Yamaha motors Uk today to get refurbished .They have to be sent through Yamaha dealer,they don't deal direct with the public.

In the future try and seek out an automobile injector cleaning service. They can usually test, clean and retest injectors for a fraction of the price of using a Yamaha dealer, or Yamaha UK/Europe/etc.

Injectors are injectors. Except for those for direct injection motors.

But, hopefully, once your motor is up and running well again you won't need the injectors serviced in the future.