LTR Heat = lost power?

[Pappy]

Being that this quad is FI, I was wondering if it will react similarly to other vehicles with FI when hot, humid conditions are encountered.

I had a member here drop of his LTR last night for a valve adjustment, but he was the second person in the past week to complain of a slight drop in felt power. It has finally turned to summer here and the thought hit me about the system this quad uses to sample air and make adjustments to the FI.

Any info would be appreciated.

[bwamos]

I don't beleive the LT-R has any air/exhaust sampling. I know there's no O2 sensor on the exhaust side. I don't beleive there's a mass air sensor on the intake either.

I think you just set the program and it runs what it is set at using rpm & throttle position sensors..

I don't think it will be long before people have programs for different conditions. In the hot 90deg+ w/ high humidity they are probably running fat.

[Pappy]

That is what I am thinking, just hadnt looked into how this animal eats. Both complained of it feeling lazy which indicated to me a rich condition etc.

[jfarrar30]

i had to lean mine out a tad with the FIMAK when the temps got into the 90's.the quad does have an air temp sensor.plus the coolant temp .my cannondale would do the same thing.

[tlronny]

I would think it is an air density sensor in the airbox as it wont know the altitude to adjust for if it measures temp. ?

[GPracer2500]

Yep, they use a barometric pressure sensor in the intake to adjust for altitude. Temp sensors for intake and water allow for further adjustments. These are open-loop systems (I believe the LTR's is made by Keihin?) and don't use an oxygen sensor to measure combustion gasses. They don't have MAFs either. They make adjustments for temps and altitude but not increased flow from a/m parts.

[bwamos]

Good stuff.

[bwamos]

Edit:
Deleted post.

How the heck did I get that posted in this thread.. LOL.

[plkmonster2]

My GSXR has a bunch of sensors. One for temp, one outside the box for barometric pressure, one inside for the ram air pressure, and one for the vaccum for the secondaries. Most FI bikes will automatically adjust for altitude, humidity (Barometric pressure), and air temp. I wonder where they put the pressure sensor? I would like to see it put into the box, and have a ram air hooked up. It would get more air, and the sensor would recognize it.

[YFZRB]

Originally posted by Pappy
Being that this quad is FI, I was wondering if it will react similarly to other vehicles with FI when hot, humid conditions are encountered.

I had a member here drop of his LTR last night for a valve adjustment, but he was the second person in the past week to complain of a slight drop in felt power. It has finally turned to summer here and the thought hit me about the system this quad uses to sample air and make adjustments to the FI.

Any info would be appreciated.

How do you guys deal with the wet weather with a carburated engine? Say an 06 YFZ?

[plkmonster2]

If it gets hotter, or more humid, you usually lean it out a tad. I leave my bike alone. It is dead on in 50 or so degree weather at my 1000 feet, or about 60-70 at sea level. Approximate humidity is 20 percent to 50 or so. When I did adjust for altitude/temp/humidity, I noticed very very slight to no power change, except when going from summer to winter jetting.