Rough idle solved....but now another question

[Aquamaniac]

Hey folks.....new Yamaha owner and new to this forum!
Recently purchased a 2005 Yamaha F150 TXRD. Compression was excellent and even in all four. Computer showed 420 hrs with 63% 1000-2000 and 24% 3000-4000 with only 2% 4000-5000 and 0% over 5K.
Took a while for me to get it mounted and rigged. Finally was ready and ran it on the muffs. Seemed to idle rough. Although I was pretty meticulous about completely draining fuel tank, adding fresh non ethanol fuel, and changing Racor filter......I wondered if an injector was amiss.
Was about to pull the trigger on a refurb injector set as well as a complete filter set (main,VST, and inline)....when I figured I would check the plugs (even though they were installed new by seller).
Lo and behold.......glad I did!
Found number three and four plug wires had been switched by seller when reinstalled after showing me compression. ARRRGGGHHHH!!!!!!!!
Corrected the situation and motor was SMOOTH. O happy day!!!!
However, here is the new question......
What (if any) issues does anyone out there see that this might have caused?
The motor was only briefly run with the wires switched. Once or twice briefly on muffs and once briefly in the water to see if it would warm up and 'sort itself out'
No long run time or high RPMs.
Can't imagine it was too good, but any thoughts on subsequent trouble to expect?
Thanks!

[fairdeal]

Found number three and four plug wires had been switched by seller when reinstalled after showing me compression. ......

What (if any) issues does anyone out there see that this might have caused?

The motor was only briefly run with the wires switched!

Its fine. No "issues".

Don't give it another thought.

[Aquamaniac]

Thanks FD......will sleep better now!
Sure runs better after getting plug wires right......but still not as smooth as I think it should be.
Have a Honda 90 four stroke on my old Aquasport 170 and it is the proverbial sewing machine. Obviously the Yam F150 is substantially bigger motor, but seems it should be able to be tweaked and made to be a sewing machine as well. Never have had the opportunity to see what a F150 that is dialed in runs like....but I suspect somewhat better than this one.
Anyone have any thoughts on a sensible, sound 'plan' to make this motor do what I think it is capable of doing?
Any guidance is definitely appreciated!

[99yam40]

find a shop where a Yamaha master tech works and have them check it out, or find someone with a F150 and see how their motor runs to see if it is differant than yours before finding the proper shop to have it looked at

Firing plugs when the valves are not closed could burn valves, but would take a while

[Aquamaniac]

Hey 99,
Sound advice....there is in fact a shop fairly near here that does list a Yamaha Master.
Might have to go that route, but I guess I was looking for a "step by step" list of things I might check and possibly adjust to make a difference (without screwing it up) While I am a pretty fair auto/truck/farm equipment mechanic, after spending a LOT of time reading many of Rodbolt's threads.....I came away with a healthy respect for Yamaha Master Mechanics.
Hey, maybe it just needs to get run now and get settled in. We shall see.....
Thanks!

[TownsendsFJR1300]

Never have had the opportunity to see what a F150 that is dialed in runs like....but I suspect somewhat better than this one.
Anyone have any thoughts on a sensible, sound 'plan' to make this motor do what I think it is capable of doing?
Any guidance is definitely appreciated!

Here's a video I took of mine sometime ago, just showing the water pump.

You can see, especially towards the end of the video (at 700 RPM's) how smooth it is.

Obviously it'd be quieter if it was in the water idling:

1st Link, Flushing F150 Video by SRT-60 | Photobucket

It should be noted that I had the low idle syndrome when new and eventually a Yamaha MASTER TECHNICIAN, with computer hooked up, tweeked it, raised the idle to normal and its pretty darn smooth...

[Aquamaniac]

Now THAT is what I am talking about!
Definitely smooth..........
I have been digesting all the low idle threads....light night time reading. HAHAHA
Getting schooled.
I will hopefully run it around tomorrow and see what comes.
Appreciate the video!

[TownsendsFJR1300]

Yepper! Please post back what you find.

BTW, prior to my Master Tech fixing it, another Yamaha tech (don't know his rank), I literally watched him, with a screw driver, TUNE A VERY NASTY VIBRATION into the engine (trying to raise the idle). They left me hanging(vibrating so bad it would "walk fully to right steering lock in the water).

A good MT is worth his weight in g0ld. I won't let anyone else but a MT touch my engine (I do 99% of the maintenance).

[rodbolt17]

you don't really need a master tech.

you do NEED a tech that understands how a speed density open loop EFI system works.

after that its gravy.

[TownsendsFJR1300]

you don't really need a master tech.

you do NEED a tech that understands how a speed density open loop EFI system works.

after that its gravy.

I don't think you realize how many mechanic's (not only Yamaha) don't know this stuff.

You know I've posted about them replacing my entire throttle bodies for the low idle. Then again, (another mechanic) adjusting the engine screwing it up MORE (with now a nasty vib).

It says "Yamaha" on the store front, it can have certificates on the wall.

When the customer doesn't know what the issue is, to ask for or see if they know how an open loop EFI system isn't going to happen... Your pretty much at the mercy and hope they know what their doing...

I've had similar issues at Honda and Kawasaki MC shops and came close to suing Honda as the dealership, after a warranty repair, would NOT repair a good oil leak THEY INTRODUCED into my G0ldwing engine. Says Honda on the store front, but who's working on it??? Another dealership found the mechanic induced leak and Honda did pick up the tab..

[Aquamaniac]

Rodbolt.....
Well then, I am willing and able to be schooled. I do have a basic understanding of the system. Can dialing it in be accomplished without specialized tools?
Seems I was reading one of your threads that made me feel that a multimeter and a Swiss Army knife was sufficient....IF you understood how the system worked. .

[TownsendsFJR1300]

Rodbolt.....
Well then, I am willing and able to be schooled. I do have a basic understanding of the system. Can dialing it in be accomplished without specialized tools?
Seems I was reading one of your threads that made me feel that a multimeter and a Swiss Army knife was sufficient....IF you understood how the system worked. .

Here's the thread he usually refer to re adjusting it:

http://www.yamahaoutboardparts.com/f...0-th15195.html