2016 VF115LA Runs rough at idle and low RPM, but seems to run fine at high RPM

[dgsaunde@gmail.com]

My motor suddenly started running rough one day at all speeds and idle. I initially thought mis-fire but found good spark on all 4. I replaced fuel filters and added 12oz of fuel injector cleaner and ran it wide open for a while, then at different speeds, and accelerating and decelerating and it made a remarkable improvement at high speeds, but at lower speeds it intermittently runs rough, and idles rough. Anyone have any suggestions please? Also, is the diagnostic cable worth the purchase? Would it help me in this case? Thanks in advance, David.

[99yam40]

I would start out
monitor fuel pressures to make sure in spec,
replace all filters and clean/service the VST & injectors
replace plugs

[TownsendsFJR1300]

Plus 1 on the spark plugs...

How many hours on the engine?


The diagnostic cable / YDS IMO is well worth the cost which is less than ONE visit to the shop..

[dgsaunde@gmail.com]

Thanks again folks. I will be replacing the plugs today, I'm 2nd owner and as far as I know they're factory. I'm looking at buying the service manual and YDS now, but GOOGLE just ain't helping me locate the YDS for my model, best I can find is up to 2013. Would anyone happen to know better please?

[99yam40]

I have a feeling Yamaha will only sell the new stuff to dealers
you might get by with the older

[dgsaunde@gmail.com]

I found it! YDS PRO2 I will update this as I go.

[dgsaunde@gmail.com]

Thanks guys, swapped all (4) plugs and she hasn't missed a lick. Inre to the YDS PRO2: One reliable source told me there is no publicly available YDS for my 2016 model and only option for computer diag is to take it to the dealer. Another reliable source led me to: http://www.brpdiagnostics.com/yamaha-yds-pro2/ Bob, who seems to only communicate via email (pwcdiagnostics@gmail.com). was quite emphatic that this would work for my VF115LA. I asked for pics of connectors: 3pin-yamaha marine-connector.jpg
If I'm correct, the connectors on my motor, which have "W" and "S" clearly labeled on the sheath, are inline, as opposed to 1 pin over 2 as shown on Bob's model.
I wanted to continue and send Bob pics of my connectors,but I just can't stomach his brashness.
If Bob truly has this device for the VF115LA, his complete lack of marketing and customer service skills is preventing him from selling more. He does use PayPal strictly.
I also spoke to "Vladimir" inre to: https://www.powersports-diag.com/en/...ostic-kit.html.He too tried to convince me his would work on the VF115LA.

The model list for both are the same and neither have VF115LA listed.

Fortunately I escaped a costly trip to the dealer, and hopefully a YDS will be available to the public soon.

Thanks again folks!

[TownsendsFJR1300]

Congrates on the fix..


I suspect it'll work of he states it will. Pay Pal will back you up if it doesn't (and you get ****ed around)..

[dgsaunde@gmail.com]

I ***** at idle almost exclusively, I trade between *****ing motor but mostly the outboard at idle. It seems as tho my fuel system is loading up from idling for so long, it will begin to run rough, but if I run it as fast I can, it will eventually starting running properly again. I just recently siphoned as much fuel out as possible, added some water removal, ran that down to empty, and then added couple gallons with bottle of injector cleaner. There was water in my fuel so replaced all the filters as well. This seemed to correct my problem, but of course it came back. Is it possible for that fuel injection system to load up on fuel, or maybe even exhaust? Thanks in advance, David

[99yam40]

I ***** at idle almost exclusively, I trade between *****ing motor but mostly the outboard at idle. It seems as tho my fuel system is loading up from idling for so long, it will begin to run rough, but if I run it as fast I can, it will eventually starting running properly again. I just recently siphoned as much fuel out as possible, added some water removal, ran that down to empty, and then added couple gallons with bottle of injector cleaner. There was water in my fuel so replaced all the filters as well. This seemed to correct my problem, but of course it came back. Is it possible for that fuel injection system to load up on fuel, or maybe even exhaust? Thanks in advance, David

water in fuel tank will roll around on the bottom until is gets picked up and sent into the system again.
you need to remove all of the water and find out and fix where it is getting into the tank.

I have no idea what you mean by load up on fuel or exhaust

[pstephens46]

Never heard of four stroke motors loading up on fuel. You should be able to run idle speed until the tank runs empty. If you found water in fuel, find out why. YDS will not help you with this.