kicking myself, purchased tldi

[rount5]

Well I was very excited to have made my first outboard purchase of a new Nissan 40 TLDI for my Achilles inflatable. It's a huge change from the 15hp I was running. But now I'm kicking myself for not fully understanding what I was purchasing. I live in northern California and have recently found that Tohatsu says it doesn't compensate for higher altitudes and is only designed to run up to 3000ft. So now all those mountain lakes around Lake Tahoe are out of reach. I've now got a like new outboard with only about 4-5hrs on it and I'm feeling like a total idiot. Besides fouling plugs, what else would I be doing to the engine if I brought it up to say 5000ft+? Any idea how quickly the plugs would foul? Would I be able to run it at least one full day on a set of plugs?<br /><br />- learning the hard way ...

 

[Forktail]

Re: kicking myself, purchased tldi

You'll probably be ok at the higher altitude. And it's nothing a minor jet change or carburetion adjustment wouldn't take care of. Higher altitudes cause the engine to run a richer air/fuel ratio. No physical harm will be done.

 

[LubeDude]

Re: kicking myself, purchased tldi

You will also want to get a lower pitch prop to use while you are there, That will help with the losss of power you will encounter.

 

[rount5]

Re: kicking myself, purchased tldi

Oh, man, I wish I could just change a few jets. But unfortunately this is a direct injection 2-stroke. Nothing short of an ecu map change will help me.

 

[rount5]

Re: kicking myself, purchased tldi

Unless I'm wrong, please tell me I'm wrong!!!

 

[NOSLEEP]

Re: kicking myself, purchased tldi

Your motor will run fine @5000 feet.<br />It is a direct injection motor.It will Idle the<br />same as at sea level. It will only suffer a<br />minor loss off RPM and WOT power.Perhaps around<br />500 RPM. I run my motor @ 5000 FT regularly.<br />What makes you think you will have a problem?<br />Is there something wrong with your motor?

 

[rount5]

Re: kicking myself, purchased tldi

I was told by Tohatsu that it doesn't have any way to change the fuel mixture for altitude changes. So they only recommend running it to 3000ft. I'd like to try it at 5000ft or so, but I'm not sure what will happen. Do I try and take the chance? It would possibly not only ruin a weekend trip but I'm more concerned with creating engine problems that I'll have to fix in order for it to run properly again at sea level. That's outside of just changing a few plugs. Or do I bite the bullet and try to get rid of it with big $$$ loss? That's why I'm kickin' myself.

 

[NOSLEEP]

Re: kicking myself, purchased tldi

It doesnt need to be changed. It will run fine.<br />You will need to run it alot higher than 5000 ft<br />to create any kind of running problem.<br />It will run richer not leaner. What problem?

 

[rickdb1boat]

Re: kicking myself, purchased tldi

Remember, thinner air the higher you go, so NOSLEEP is correct when he said it will just run richer, which is fine. Take some extra plugs with you and have fun... You bought a great motor. Stick with it..

 

[voodoo]

Re: kicking myself, purchased tldi

Even if it loses 25% of the power at 5000 feet you still have twice what you had.

 

[rickdb1boat]

Re: kicking myself, purchased tldi

And Lubedude has a good point on lowering the prop pitch to keep your RPM's in spec...

 

[Forktail]

Re: kicking myself, purchased tldi

Sorry rount5, I didn't realize that was a DI outboard. Most DI's have some type of computerized fuel management and ignition management system. I find it odd that Nissan would only program the DI system for 3000 feet.

 

[rount5]

Re: kicking myself, purchased tldi

Yeah, I was a bit bewildered that a "fuel injection" wouldn't have any means to compensate for higher altitudes. But from what everyone's saying, running rich for a while is really no harm except for fouled plugs. I was kinda worried about carbon build-up or something like that besides the plugs. The prop that came with it is 11.6 x 11, which is not enough pitch at sea level. So I'll just keep that one for higher altitudes and I'm purchasing a 14 pitch Hustler setup for down low. Thanks everyone for your comments and advise!!! I'll just have to take it up and see how she runs. I'll post my results when I do.

 

[youngboater]

Re: kicking myself, purchased tldi

I live in the deserts around 1,000 feet. I boat about 1,500 feet above sea level. Usually a few times a year I go up to 8000-9000 feet above sea level and I do just fine. I even use the same size pitch prop. On my 75HP 2-stroke I on'y lose about 5-8 MPH. My 8HP kicker seems to lose a lot more but it still runs fine. I was at about 8,500 feet for a week running the engines at least 3-5 houre each day and never fouled one plug. Nothing happened at high elevations except power loss due to elevation. The motors are ment to be run at about 1,500 and they do fine at high elevations. Good Luck

 

[TELMANMN]

Re: kicking myself, purchased tldi

Have you tried higher octane gas or a octane substitute? Maybe even adding sea foam? Worht a try and don't think it would hurt anything.

 

[backdraft]

Re: kicking myself, purchased tldi

I live at 5500 feet and boat at 4 to 7 thousand feet.. The only thing you should do is change to a lower pitch prop. Your motor will run almost the same at a higher altitude. Sounds like someone is blowing smoke and trying to berate your purchase. The computer on this motor will compensate to a degree for the change in air density. nevjb

 

[rount5]

Re: kicking myself, purchased tldi

Hmmm..., when I talk to Tohatsu, they say it doesn't have anyway to detect changes for higher altitudes. They are also saying it's being developed and next years TLDI should have that capability. Does that change your opinions or are you saying regardless of what Tohatsu is saying, the TLDI can still compensate somewhat??? Does anyone who has replied actually have a TLDI and runs it at 5000ft+? I'm leaning more towards it doesn't compensate and it will just run richer to some degree. At some altitude, it may even run so rich that it won't run at all, possible???

 

[Peter J Fraser]

Re: kicking myself, purchased tldi

rount5<br /><br />You could get a greater variation in air density at sea level between a high and low pressure weather system than you are probably going to see fron 3 - 5000ft and the engine will still run ok.<br />The ecm must have some way of enrichening the fuel for a cold start so the engine will run so it stands to reason that will be able to compensate for altitude / density to some degree anyway.<br />Go and try it at that altitude and log the results for your own interests.<br /><br />Good luck<br /><br />Peter

 

[NOSLEEP]

Re: kicking myself, purchased tldi

If your planning on running your out board at more<br />than 10000ft. Then you may have a valid concern<br />rount5.I ran a 1985 evinrude 120 at more than<br />5000 ft for 20 years switching to sea level every<br />year for holidays and I never had to modify the<br />jets. The motor just had more power at the lower<br />elevations.

 

[rount5]

Re: kicking myself, purchased tldi

Ok, thanks again for all the great responses!!! I'll stop kicking myself and hopefully in the next few weeks I'll be running it up by Lake Tahoe.