Fuel Consumption Port vs Starboard

YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
My starboard motor uses 15L/hr more than Port whilst at 4000+ rpm. These readings are from VesselView and confirmed by actual tank drain. I also have the throttle open more on the starboard side to sync with port.

I have swapped the following parts between engines to no avail:
wires
cap/rotor
coil
throttle position sensor

Plugs are new. Fuel filters are all new. Injectors all new. 

Just did a compression test on starboard and all are between 130-136 psi. 

Not sure if it’s relevant but I just noticed that when shutting down the starboard motor it gurgles as if water is flooding in or out. I never noticed that before. It also has a tick, maybe a lifter issue?

https://youtube.com/shorts/k_yTjS-nEtI?feature=share

What am I missing?!
2008 350 EC on Georgian Bay
Post edited by YYZRC on
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Comments

  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    @212rowboat any thoughts? Your expertise would be much appreciated!
    2008 350 EC on Georgian Bay
  • Liberty44140Liberty44140 Bay Village & Marblehead, OH.Member Posts: 4,018 ✭✭✭✭✭
    This has nothing to do with the center fuel valve being open, does it? 
    07' Cruisers 390 (Previous Rinker's: 06' 342EC & 01' 310FV)

  • aero3113aero3113 Long Island, NYMember Posts: 8,178 ✭✭✭✭✭
    Is the tick new? Is it possible it’s an exhaust leak or a wire arcing? Or is it definitely a metallic tick?
    2008 330EC
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    This has nothing to do with the center fuel valve being open, does it? 
    What do you mean by the center fuel valve? Thanks!
    2008 350 EC on Georgian Bay
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    aero3113 said:
    Is the tick new? Is it possible it’s an exhaust leak or a wire arcing? Or is it definitely a metallic tick?
    I believe the ticking is new and it increases with engine rpm. Sounds metallic to me and toward the front of the engine I would say. 
    2008 350 EC on Georgian Bay
  • aero3113aero3113 Long Island, NYMember Posts: 8,178 ✭✭✭✭✭
    Double check for an exhaust leak or a arcing wire,I’ve been tricked twice. Once on my Healey, turned out to be an exhaust manifold gasket and once on my 242 that turned out to be a cut spark plug wire. I was shocked at how it sounded, definitely didn’t think it was exhaust or spark. 
    2008 330EC
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    Here’s a vid that has the tapping and the water rushing. The sound when the motor is shut off is the trim tabs retracting. 

    2008 350 EC on Georgian Bay
  • Dream_InnDream_Inn Annapolis, MDMember, Moderator Posts: 7,184 mod
    YYZRC said:
    This has nothing to do with the center fuel valve being open, does it? 
    What do you mean by the center fuel valve? Thanks!

    You have 3 valve switches on your fuel lines to the engines.  The center one should be off and the two sides should be open.  This allows each motor to feed off of each individual tank.  If the center one is open (as well as the 2 sides), it may feed more off of one side than the other.

    Dream 'Inn III -- 2008 400 Express

  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    Ohhh yes I always have the crossover closed. 
    2008 350 EC on Georgian Bay
  • GrahamuGrahamu Lefroy, Lake Simcoe, ON, CDAMember Posts: 705 ✭✭✭
    I have a similar fuel burn at 3600 RPM with one engine slightly higher. I have never worried about it as it represents less than 2% of total fuel used per hour. At that speed a number of issues could effect it, prop condition, drive tilt angle, trim tab settings. I have never checked it under a no load condition but will do this weekend.
  • captkevincaptkevin ChicagoMember Posts: 100 ✭✭
    For comparison what are the compression numbers on the other engine reading?
    2004 232
    2021 Yamaha Fx svho
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    edited September 15
    @Grahamu for reference, no load and with load up to 3000 rpm mine are within 0.5 lph. After 3000 rpm things go awry. 

    Port WOT at 5000 rpm and starboard WOT around 4700 rpm. 

    My starboard motor always burned more fuel than port but (about 5 lph at 4000 rpm) but it got much worse after I clipped the rock coming out of Frying Pan.  I have brand new props but I wonder if maybe I bent the prop shaft a bit.  Will check it out at haul out as I need to have the skeg fixed.
    Post edited by YYZRC on
    2008 350 EC on Georgian Bay
  • GrahamuGrahamu Lefroy, Lake Simcoe, ON, CDAMember Posts: 705 ✭✭✭
    @YYZRC if you are experiencing the same under no load I think you can rule out the drive train. I know very little about fuel injection and electronic ignition, I'm a carb guy, but are there tuning instructions for them?
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    I haven’t gone over 3000 with no load. 
    2008 350 EC on Georgian Bay
  • GrahamuGrahamu Lefroy, Lake Simcoe, ON, CDAMember Posts: 705 ✭✭✭
    I think you would be ok up to 4000rpm briefly but maybe others would like to comment on that.
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    Pretty sure there is a limiter at 3500!
    2008 350 EC on Georgian Bay
  • GrahamuGrahamu Lefroy, Lake Simcoe, ON, CDAMember Posts: 705 ✭✭✭
    Don't know about that but even 3500 would give some indication.
  • 212rowboat212rowboat Member Posts: 2,584 ✭✭✭✭✭
    Does starboard run cooler than port?  Rich fuel runs cooler... 

    It does sound like a lifter.  A leak on the inner exhaust manifolds (corrosion you cant see) will drain back into the cylinder... just a little at first and then progressively worse... its well capable of collapsing a lifter if water (especially condensed steam collecting atop a once/recently hot piston) is present in the cylinder... the first thing to go with that would be a lifter... then a bent lifter rod.. then a blown head gasket... then a bent connecting rod or windowed piston.... 

    The extra fuel, though, accompanied by the lifter tick could just as easily be a skipped timing chain- a degree or two out of mechanical (valve event/crank position) giving same symptoms and certainly capable of collapsing a lifter.    

    How many hours on the motors? Manifolds?  Timing chains usually show their weakness early and if they check out you get a good long life out of them... manifolds could be fine- or not- the easiest tell for them is rust on plug... 

    Get a good vacuum gauge- an analog one.. Google for vacuum signals and charts, and what they mean.  You'll find out quicker doing that than anything else.  




  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    Thanks @212rowboat !

    Both motors run same temp (indicated 160 degrees). The motors have 190 hours on them and risers/manifolds are original. Fresh water boat always. No rust on plugs. 

    I am having to add more load to starboard to get same rpm as port. Engine is working harder so of course it uses more fuel to do so. Is there any chance the outdrive is causing strain on the engine? I assume the drive would just grenade if something was out of spec. I have probably put 15 hours on the boat since hitting the rock. 
    2008 350 EC on Georgian Bay
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    YYZRC said:

    Not sure if it’s relevant but I just noticed that when shutting down the starboard motor it gurgles as if water is flooding in or out. I never noticed that before.
    I wonder if my water distribution housing has failed?
    2008 350 EC on Georgian Bay
  • Black_DiamondBlack_Diamond Holland, MichiganMember Posts: 5,429 ✭✭✭✭✭
    Don’t discount what a misaligned drive can do to performance / fuel burn. 

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
  • 212rowboat212rowboat Member Posts: 2,584 ✭✭✭✭✭
    Do both engines load the alternator?  Parasitic drag on an engine can really sap power.  B3's and sea pump? What kind of condition is the pump in on the offending engine?  That's another parasitic draw and one related to the gurgling noise.  

    You can do a cheap diagnostic... redneck stethoscope- long handled screwdriver and put your ear to the end of the handle... could the ticking be coming from the sea pump?  Put the end on the intake manifold and work around the perimeter to determine if it's a lifter and which one.  

    @Black_Diamond is smart fella- a ujoint in your drive or the cardian connection could be worn, and they tick, too... it would do it in neutral as well as in gear and it too would increase with RPM. 
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    edited September 16
    Thanks @212rowboat and @Black_Diamond

    I swapped alternators and no change. They are B3 drives with 20p 4x4s. Raw water cooling, impellers are just over one season old. Both drives were serviced at the start of the season including new gimbal bearings so I trust that I started the season off aligned!

    Thinking now that I knocked the drive out of alignment when I clipped the rock. Makes perfect sense. 

    I wonder if the manifold drain assembly (#8) has failed and thats the water rushing sound I hear?

     

    @212rowboat is it possible to remove the valve cover and determine if a rocker is loose by manipulating the push rod? Can I turn the engine via the alternator bolt or is there a better way? I watched a few valve adjustment vids that suggested it was possible to do so.  Or would you recommend that I inspect/adjust with the valve cover off and engine running?
    Post edited by YYZRC on
    2008 350 EC on Georgian Bay
  • 212rowboat212rowboat Member Posts: 2,584 ✭✭✭✭✭
    Get that redneck stethoscope out before you remove anything... tip touching engine, handle to ear... you'll locate the tapping in no time.. 

    IF it's a lifter, and knowing the location via the stethoscope,  you'll have it narrowed down to one cylinder- but may not know if it's exhaust or intake.  

    Pull the covers on that bank and see which rocker wobbles a little.  They shouldn't wobbles at all.  
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    edited September 17
    Tapping was on the port side of the engine. Pulled the valve cover off and several lifters were wobbly. While I was tearing it down my boat neighbour / retired mechanic strolled over and lent a hand. Got the valves adjusted and no more ticking! Was able to turn the engine by the harmonic balancer bolt. 

    It was such an easy process I think I will do the other banks when I have some free time. 
    2008 350 EC on Georgian Bay
  • aero3113aero3113 Long Island, NYMember Posts: 8,178 ✭✭✭✭✭
    Awesome @YYZRC ! 👍🏻👍🏻
    2008 330EC
  • captkevincaptkevin ChicagoMember Posts: 100 ✭✭
    Nice when its an easy fix.
    2004 232
    2021 Yamaha Fx svho
  • GrahamuGrahamu Lefroy, Lake Simcoe, ON, CDAMember Posts: 705 ✭✭✭
    @YYZRC, did adjusting the lifters change the fuel consumption on that engine?
  • YYZRCYYZRC Georgian BayMember Posts: 3,883 ✭✭✭✭✭
    I haven't had her out yet.  What are your thoughts on the possibility that the timing is off?
    2008 350 EC on Georgian Bay
  • GrahamuGrahamu Lefroy, Lake Simcoe, ON, CDAMember Posts: 705 ✭✭✭
    Possible but not likely seeing as it happened after the rock incident. See what the readings are after your next run.
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