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The TPS adjustment thread


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Going entirely by my memory.. i believe the tps guard first showed up on the sx based models, after some reports of the tps being damaged by rocks, etc.. On those models the tps was exposed, not hidden behind the gas tank. FF to today where now several models use the same tps, even though the tps is hidden behind a frame brace, and in the case of the exc also behind the gas tank. So it's plausible that they're just using the same part as-is across models to make manufacturing and parts management easier. However, they didn't have to make it such a bugger to remove the guard, so it's also plausible that they're trying to discourage fiddling with it to appease the epa.

I could never encourage removing safety equipment, but it does seem like the tps would be reasonably protected even without the guard, given its location behind the frame brace and gas tank.

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I absolutely agree with sirthumpalot. I just spent the day with his tool on my 2017 FE501. For reference I ended up at.76 and stock setting was.61. I drilled a few 1" holes in the top of the airbox, and have an FMF RCT 4.1 on for an idea of how much air I'm flowing. I'm just a hair rich right now, but I'll have the FC450 intake boot on Tuesday and that extra flow should lean it out that extra little bit. Or I'll tweek it.

Curious side note for me. My idle didn't really change enough to mess with it. I was expecting it to, but it's right about where it was when I started, oddly enough. Be curious to see if others experience the same.

This bike rips now! Pulls hard everywhere. No longer anemic![/quot

Is fmf rct 4.1 a straight thru design or is there a screen in there? I removed the end screen on my sxf 450 akrapovic and wonder if i should increase tps??

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Is fmf rct 4.1 a straight thru design or is there a screen in there? I removed the end screen on my sxf 450 akrapovic and wonder if i should increase tps??

It's straight through, unless you have the spark arrestor screen in...

I don't know how your bike runs, but if it's bone stock with the slip-on, it's probably overly lean now. My seat of the pants adjustments with the TPS tool made a huge difference in how the bike runs. I'm sure it could be way better with a piggyback ECU and dyno tune, but it's night and day better with just the TPS adjustment.

Edited by RallyMoto
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Hey rally, be careful not to lean out your bike to much with a muffler and other mods without a remap to increase fueling. That 4.1 really flows a lot more air as I'm sure you notice in the top end. A lot of people think a simple adjust of the tps will tweak or richen up the bike enough to make it right. That's not true. The main benefit of adjusting the tps is to reduce backfire on decel and help with flame outs. Both of those occur at little to no throttle. So basically your tps adjustment affects about the 0-1/4 throttle range. As stated earlier by sirthumplot twisting the throttle goes from .610 to over 4.0. Your adjustment you made basically increased the tps by .15 along the entire throttle range which is nothing when you get to the 3.5 - 4.0 range (fifteen hundredths compared 4.0). It can be confusing unless you think of it this way.

When you remap you get the correct map on your ecu for you bike and it's accessories, basically like a rejet on a carb. The new map will increase fuel over the entire throttle range, including the full throttle range where you need it for the 4.1. You on the other hand increased air in and really increased exhaust out, but left the fuel injection nearly the same.

I've been there and done that on my 16' ktm 500 exc with my 4.1 fmf titanium muffler and the remap is a game changer. You can feel the bike enjoying the extra fuel when it's needed. So be cautious until remaps are figured out on your 17.

Last the tps is a great way to fix decel pops and flameouts on a fully stock bike or desmogged bike. The tps tool is the way to go and I feel a must to see where you are. When I remapped I found .599 to be the best, where before .662 was better.

 

Thanks for the points Dan. They make sense and I do agree that the TPS isn't a perfect solution, but it makes a pretty good first step, and not just on the bottom.  Maybe it has to do with the separate maps for each gear on this bike.  I have lots of experience tuning carbs, so I know what lean feels like.  It's not perfect but it's pretty good now.  My brother ran over 300 hrs on his completely uncorked 500EXC with just a TPS tune and never had an issue.  I do plan to get an aftermarket piggyback tuner, but none are available yet.  Map updates/swaps are unavailable for these new models and it sounds like that'll be awhile before it gets sorted with the locked stock ECUs.  I know PowerCommander is working on it and JD is looking for a bike to build a tune for.

 

Did you ever have an O2 sensor hooked up tuning your bike?  I'd be curious to know what your fuel curve looked like with just the TPS tuned, if you ever got over 14.5AFRs?

 

I wouldn't run my bike with this setup if it felt too lean!

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Thanks for the points Dan. They make sense and I do agree that the TPS isn't a perfect solution, but it makes a pretty good first step, and not just on the bottom.  Maybe it has to do with the separate maps for each gear on this bike.  I have lots of experience tuning carbs, so I know what lean feels like.  It's not perfect but it's pretty good now.  My brother ran over 300 hrs on his completely uncorked 500EXC with just a TPS tune and never had an issue.  I do plan to get an aftermarket piggyback tuner, but none are available yet.  Map updates/swaps are unavailable for these new models and it sounds like that'll be awhile before it gets sorted with the locked stock ECUs.  I know PowerCommander is working on it and JD is looking for a bike to build a tune for.

 

Did you ever have an O2 sensor hooked up tuning your bike?  I'd be curious to know what your fuel curve looked like with just the TPS tuned, if you ever got over 14.5AFRs?

 

I wouldn't run my bike with this setup if it felt too lean!

There was a guy who plugged an 02 sensor on a 2016 and used a JD tuner, set everything at 12 to 1 air fuel ratio. He posted his numbers, but IMO they were crazy rich and unnecessary, just knowing my own experience with tuning with a jd, the settings are critical, rich or lean either side of perfect can kill power.

 With a good tune, expect about a 5 mile drop per tank over stock.

 

The 2012 - 2016 were lean everywhere with no noise screen, I guarantee the 2017's are even worse, despite what people might say.

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There was a guy who plugged an 02 sensor on a 2016 and used a JD tuner, set everything at 12 to 1 air fuel ratio. He posted his numbers, but IMO they were crazy rich and unnecessary, just knowing my own experience with tuning with a jd, the settings are critical, rich or lean either side of perfect can kill power.

 With a good tune, expect about a 5 mile drop per tank over stock.

 

The 2012 - 2016 were lean everywhere with no noise screen, I guarantee the 2017's are even worse, despite what people might say.

 

12:1 on an NA motor sounds pretty rich.  I used to tune my turbo trucks that rich under full boost.  12.5-13.5:1 is a bit sweeter in my experience.  I doubt I'll ever pay for a dyno tune on this bike, so I'll probably buy a PCV or JD tuner with a base map preloaded and tweak it from there by feel.

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2016 sxf 450 fe

With or without the insert in the akrapovic slip on the bike has a very slight pop when cruising with closed throttle....takes a few revolutions to start...and sometimes dies if i fully open the throttle abruptly. The muffler is black at the end + when i give it gas the rpms go up and then fall below idle for a moment...

I am confused if the bike runs rich or lean? The akrapovic has another insert in the middle which stock exhaust does not...so could it be too rich with akra setup?

I bought the tps tool and it showed 0.50 at my personal rpms....i went to 0.55 but to be honest i do not feel much difference. Do not know what to do next...just leave it as it is? What are the main things to determine if the bike is running at optimal af ratio...without going to dyno?

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2016 sxf 450 fe

With or without the insert in the akrapovic slip on the bike has a very slight pop when cruising with closed throttle....takes a few revolutions to start...and sometimes dies if i fully open the throttle abruptly. The muffler is black at the end + when i give it gas the rpms go up and then fall below idle for a moment...

I am confused if the bike runs rich or lean? The akrapovic has another insert in the middle which stock exhaust does not...so could it be too rich with akra setup?

I bought the tps tool and it showed 0.50 at my personal rpms....i went to 0.55 but to be honest i do not feel much difference. Do not know what to do next...just leave it as it is? What are the main things to determine if the bike is running at optimal af ratio...without going to dyno?

Being that you have the closed course competition map , I would think it would be pretty good stock.  By the sound though, you have leanous at small throttle openings and more than rich else where. Usually the hard blip throttle from idle that flames out is a lean issue.  A low idle can exaggerate the issue even more.

 

IMO, on that bike put the tps at stock, as being the idle is tied to the throttle plate, set up is going to be touchy, and some kind of base line with the throttle plate, the idle and the tps has to happen to function properly and is probably in the service manual. If your bike ran better with stock can, then mapping adjustments would be best route for the Akra verses messing with the tps, other than making sure it is set correctly.

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12:1 on an NA motor sounds pretty rich.  I used to tune my turbo trucks that rich under full boost.  12.5-13.5:1 is a bit sweeter in my experience.  I doubt I'll ever pay for a dyno tune on this bike, so I'll probably buy a PCV or JD tuner with a base map preloaded and tweak it from there by feel.

Yeah I was hoping to hear some reasonable numbers that jived with what I was seeing on mine, but I know mine would run like crap on his numbers.

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2016 sxf 450 fe

With or without the insert in the akrapovic slip on the bike has a very slight pop when cruising with closed throttle....takes a few revolutions to start...and sometimes dies if i fully open the throttle abruptly. The muffler is black at the end + when i give it gas the rpms go up and then fall below idle for a moment...

I am confused if the bike runs rich or lean? The akrapovic has another insert in the middle which stock exhaust does not...so could it be too rich with akra setup?

I bought the tps tool and it showed 0.50 at my personal rpms....i went to 0.55 but to be honest i do not feel much difference. Do not know what to do next...just leave it as it is? What are the main things to determine if the bike is running at optimal af ratio...without going to dyno?

 

Is your idle lower than stock?  I'm tempted to say it must be lean with the TPS voltage so low, but if the idle is lower than stock then that might be why the TPS voltage is so low.  Lean and rich symptoms can be very similar sometimes, but if you blip the throttle and the idle hangs high for a second then that typically means you're lean.  And if you blip the throttle and the idle gets really low for a few seconds then slowly speeds back up to regular idle, that typically means you're rich.  It's not 100%, but typically.  Try going the other way (leaner) with your TPS and see if that makes any improvement.  

Edited by sirthumpalot
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Yeah I was hoping to hear some reasonable numbers that jived with what I was seeing on mine, but I know mine would run like crap on his numbers.

on turbo snowmobile 11,5  . on 2 stroke snowmobile 11,8 trail (they come stock near 11.2  ) and 12,8 to 13 lean for race . on Subaru turbo high 10 to 11 they like fuel. seadoo comme lean at 13 and up but power is at 12 .  1200 ski-doo motor is the only motor i did see that like to run lean in the 13 to 13.5 . 

 

so i think 12 for ktm should be good . i guest they come stock at 14 ( i never try wideband on those )  poping indicated extremly lean . 

Edited by cisco 1
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I don't want to be a dolt here... but I have a 2003 525MXC and all of my searches for that particular vintage have come up empty, but I do accept that I'm new to the site and probably looking in the wrong places with keywords that are too short.  

I, like an idiot, pulled my Keihin FCR carb all the way apart to clean it and now need to reset the TPS in addition to everything else I have dumped in my own lap, including obscure mid-plate gaskets.  

 

Is there a harness for the RFS carbureted versions, or can I use one of these harnesses?  Lastly, since this is the mother of all TPS threads, is there any advice for a setting on that older bike?

 

Thanks ahead of time.  

 

Wes

Edited by Froggystyle
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I'm not sure what setting is recommended for the older carbed bikes, but check the manual before going too much further. Many of the old carbed bikes could be set with an ohm meter and no need for any harness or tool. The instructions were often in the manual. You can use the harness of course, just match up your tps plug to one of the pictures at www.tpstool.com.

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  • 3 weeks later...

I was just able to keep the TB on and just rotate it as much as possible to remove the plastic plate on my 17 500 exc.  The bottom screw is easily accessed and I was able to line the top screw up with the engine mount bolt hole.  Just stuck a screwdriver through that hole and backed the top screw out.  Was then able to access both mounting screws to adjust the tps.  Reinstall went fine as well.

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I may have missed it, but does anyone know the TPS values/numbers for a KTM690 Enduro R 2009. I'm running an akropovic slipon. But would like to know the recommended values/numbers for the stock and modified exhaust if possible.   Appreciate any help.

Thankyou in advance, cheers

Edited by Marty690
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3 hours ago, Marty690 said:

I may have missed it, but does anyone know the TPS values/numbers for a KTM690 Enduro R 2009. I'm running an akropovic slipon. But would like to know the recommended values/numbers for the stock and modified exhaust  if possible.   Appreciate any help.

Thankyou in advance, cheers

To anyone that's interested, i have found the following information 

Basic  TPS setting  0.50 - 0.54 Volt‘s

Emergency running TPS setting 0.70 - 0.74 Volt‘s 

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