Help Please....Motor boggin down 2004 / 115 ELPTO

[Brian Bell2]

Guys and Gals.

Got a ? for you. I took my boat out this morning and it ran great. On the way out I ran it at WOT for short bursts. Ran great. I am stilling running double oil, first tank of gas, I am down to about 1/4 tank. On the way back I ran most of the way at about 4000 to 4500 rpm, and ran at WOT for shorts bursts with no problem, about half way back I noticed I could not get the RPM's above 4000 RPM even WOT.

Got back to the house and pulled plugs and cleaned them up. The top 2 plugs were pretty dirty, the bottom 2 were pretty clean.. The dealer said since I am almost through first tank double oil, to fill her up and do not run extra oil in tank.. and see if that cures it.. Anyone with 115 elpto experience this.. any thoughts.. suggestions, before I bring it in to dealer...

thanks brian

 

[Staci Matheis]

Brian -



Make sure your gas tank vent is open. It should be a small, plastic cap - about the size of a bottle cap - probably on the right side of your boat. It only has to be unscrewed a coupla-three turns to vent properly; but, if it's tight, you could be fuel starving your motor.



Since the 115 only operates on 2 cylinders below 2,000 rpm's and you were likely idling quite a bit at the very end of the day before loading your boat on the trailer..... I would expect that two of your plugs would be fouled while the other two were clean.



me!

 

[Brian Bell2]

is the gas tank vent on the outside of the boat or in where the gas tank is?

 

[Brian Bell2]

Me !

I just looked inside and out and cannot locate what you described. I saw 2 caps on the inside back gunnel .. but they apears to be there to vent the compartment where the gas tank is and they are not hooked up to anything.. also looked inside gas cap.. nothing there to adjust as u desribe and looked in compartment where gas tank is.. i did not see anything there either.. its 2004 NX750.. I must be loosing my eyesight... or just plain too stupid to find it the gas tank vent.

 

[Brian Bell2]

I just looked inside and out and cannot locate the gas tank vent.. the only thing i found ( but did not touch ) is a copper looking thing on top of the gas tank, it has a couple wire hooked to it and i think 6 nuts.. This is driving me crazy...HELP PLEASE.....

 

[Travis Smith]

Check the spark plugs. They foul easy during break in.





T.S.

 

[J B]

Brian,

I have a 2003 115 with about 25 hours on it. During break-in I fouled the 2 plugs that are active during idle. I cleaned then and then swapped the top 2 for the bottom 2 to even out the wear. It seemed to help mine.

 

[Staci Matheis]

Brian -



Unfortunately, I am not at all familiar with your particular boat and where the vent would be..... And, now that I think of it, I think I once heard someone say that the newer boats had the vent in the cap..... I'm not sure how to check to see if it is blocked..... Maybe someone else here can tell us.....



On both Nitros I've had, the vent cap was on the right side of the boat, just above where the top cap joins the hull, about 2 feet from the back edge.



The part with wires is the gas gauge sending unit.



me!









To find out if that is the problem..... Next time you're out, when you start bogging down, take the filler cap off for a moment to let air in, then put it back on. This should temporarily relieve the problem if fuel starvaiton due to a vacuum is causing it.

 

[Brian Bell2]

Me! thanks for info.. I will try that.. I am gonna go over to west marine and pick up some new plugs.. couple guys over on the bass fishing home page think it could also be bad or fauled plugs since I was able to run WOT, except for the end of the day..

 

[Brian Bell2]

I think I found it.. on the inside of the perco gas cap there is a surge plug, its actualy on the gas cap itself. Anyway it appears that there is a black rubber hose that runs back from the gas tank to the gas cap ( not the one for filling ) this appears to be for venting air in and out of the tank.. There are 2 screws on the inside of the gas cap and when u adjust them and screw the gas cap back on the cap has a little play, for air to escape ( i think ). Anyway .. any thoughts....

 

[C C]

Did you replace the plugs and refill the tank and test again?

 

[Brian Bell2]

Cass,

Not yet, I am going over to west marine this afternoon to pick up the plugs. But dont think I will get to the water today as it is pretty darn cold out for Jacksonville. Odd thing about the gas tank,, the gauge reads 1/4 tank but it looks to be about 1/2 filled..

 

[Mikel Stephens]

Make sure your prop is tight.

 

[Scott Hammer TOXIC]

Didn't we just have a thread about not double oiling?



TOXIC

 

[Brian Bell2]

Well, I just removed the prop, checked everything out,, re-greased with spline grease, and tightened it down real good, and I replaced the plugs. Weather permitting I will fill her up with gas and test next weekend, hopefully it was just a case of failed plugs. Let you know next week, thanks for everyones help..

Brian..

BTW, when I did run it WOT, the GPS was reading 55MPH with motor trimmed little less than half way up, in some real choppy water..

Not bad for a 115 on a NX750, I am realy impressed with the performance and handling of this boat..

 

[Staci Matheis]

TOX -



That was with regard to the Optimax motors.

Brian's is carbureted.



me!

 

[J B]

Brian, my TV-18 has the vent built into the gas cap just as you describe. As far as the gas gauge, they are notorious for being incorrect. Next time you fill up when empty, make note of the gallons pumped for gauge readings of 1/4, 1/2, 3/4, full. Then at least you will know about what you have left. Also, my plastic tank has warped some, so I don't think it will hold the rated 42 gallons.

 

[TOMMY RICH]

Uh oh...you better hope it's not what I think it is. If what your gonna' do doesn't cure it and it don't get above 3 or 4000 RPM...it could be a bad module from the factory. It's more common with the 90 to 125's...I only had my boat about 2 weeks and it started boggin' down and wouldn't get above 3000 RPM. Just somethin' to keep in mind if the problem is not solved....

TEE

 

[Brian Bell2]

Tee,

Thanks for the info.. I think I am gonna just bring it on into the dealer and have them check it out.. thanks for the info..