New To Me Te250 2010 Low Hrs Questions

Next good weather day! .....so like in a month or so ha.


So I am now onto trying a CO1 @ 97, CO2 102, CO3 102 seems like that is the way to go. I may have had a rich issue this entire time at that RPM. I just rode it up a local trail and it seems much better, better than the CO1 @ 102....I won't know til I get it hot in my regulartrails though. New CTS is on order, that may have something to do with it as temp rises it gets more finicky. Last chance for this girl...unless the TXC310R ECU that rgmr250 installs works. Decided against PC5, to many wires.

Good move.
Keep trying. You might try swapping in the Spark Arrestor in also.
That is now my bike is set up.

The arrow exhaust system also helped quite a bit.
I wish you could ride mine, but I'm in PA.

DUDE, try replacing your coil!

I had this happen to me in the wet twice.

Every time it was wet the bike ran like crap.

I troubleshot it by spraying a mist of water under the tank, The bike immediately ran like crap.
The plastic body pulled away from the mounting lug allowing water to enter the coil.
Replaced the coil and the bike ran fine for a year until it did it again.
It's on the 3rd coil for 3 years now.

The coil only cost me $24USD

or even faster: try Cyclic's coil.

and Cyclic- if you don't wanna wait for the CTS... try a 1000ohm resistor in the connector after the bike warms up. (the fan might stay on though). OR: try rgmr250's cts. you'll spill coolant. I agree that the bike seems rich- is the exhaust visible and does it smell strongly?

oh yeah- take that 1-way valve (2-way actually) off of your gas cap vent. [unless you're running the vapor canister still]. they fail and sometimes will not let air in.

how do those LED lights work out for you?

you guys sure about your idle? 2000 revs is good; both bikes sound low to my ear. Maybe not, I guess I-beats would never lie.

It sounds low (and rich) to me, but then again my 2010 idles at 2300!

It might be worth trying. I've sealed my coil with silicone - anywhere water could enter. A new coil, if that cheap, might be worth trying. Both my and Cyclic are having the exact same problem, so swapping parts between bikes likely won't help us, unfortunately.

I run my idle at about 2200-2300. I think Cyclic runs his a little bit lower.

I've replaced the CTS on my bike (last year) when I had the problem and it made no difference for me.

As a note, I tried removing my db killer and just running the muffler open - no SA or DB killer - to see if a more free flowing exhaust might help (if running too rich, remove an airflow restriction and that should lean it out, in theory). No change with the low rpm bog. It did feel a little bit 'crisper' or 'snappier' in the higher revs, but it was way too loud for me.

Yeah, that's why I really want to get rid of the bog - it catches me out every once in a while - I need to get up a rock or over a log, roll the throttle and sometimes, bog, and fail. I've gotten used to riding likes the trials bikes do, and slip the clutch, rev it up, and use the clutch to feather out the power.

That is not true at all. You guys may or may not have the same symptoms, but if so- it very may well stem from different issues.

Swapping parts is a legit diagnostic. And it's easy. Try his coil if you don't wanna spend money.

...and let him try your spare (?) or new cts too.

It was worth a shot.
I find it way too loud also.

I run the S/A and no restrictor.

I agree.

BTW, I had 2 bad coils.

Bike ran so bad I wanted to throw it in the garbage....the whole bike.

Coil cost me $25.

I wish you could ride my 2010 TE-250.

Runs perfect all day long. Hopping trees, boulders, snap wheelies etc.

*NOTE the below has been edited - see the original post in the quote from Trenchcoat85 below.
On these bikes, I think it's very possible to 'sneak' air by the ECU. They are pretty simple 6sensor EFI setups:
TPS - throttle position sensor
CTS - Coolant temp sensor
CPS - crank position sensor (besides telling the ECU when the crank is in a certain position, so I can send spark at the right time, it also provides engine speed information)
O2 - Oxygen sensor - although this is disabled with the resistor plug in powerup mode, which effectively makes this a 3 sensor system.
IAT - intake air temp (integrated into the TPS sensor device)
MAP - manifold absolute pressure (also integrated into the TPS sensor device)

Most modern cars, and to varying degrees, modern EFI motorcycles will have more sensors:
TPS - throttle position sensor
CTS - Coolant temp sensor
CPS - crank position sensor (also provides engine speed information)
O2 - Oxygen sensor - often multi sensors - up and downstream of the catalytic converter, usually with a set for each cylinder bank in a V or boxer type engine when it's a true dual exhaust.
MAF - Mass airflow sensor
Some have Camshaft position sensors
IAT - Intake Air Temp
MAP - Manifold absolute pressure

The MAF (which our bikes doesn't have) is going to sense the quantity of air going to the throttle body. It uses the IAT to adjust this volume calculation based on the air temp - lower temp is denser air - more air flowing. MAP - basically a vacuum gauge will sense engine load, another important factor in providing precise fueling.

Since our bikes can only really rely on RPM, MAP and throttle position, with the CTS info to basically tell it to richen the mixture when cold, there's very little feedback to the ECU. It's no wonder they don't run as well as they could. It will have no 'sense' of how much air is flowing through - it only knows throttle position, MAP and RPM (once warmed up, the CTS isn't really in the equation any more - unless coolant temp goes above or below set thresholds). Without an O2 sensor providing A/F ratio feedback, the ECU can't make adjustments to fueling as it should - an EFI system should have O2 feedback so that it can go into closed loop mode and adjust the fueling based on the A/F ratio real-time. This seems to be why the TPS setting is so important on these bikes. On a car, it would be a little less so because of all the other sensors, it can compensate (at least somewhat) for a slightly misadjusted TPS. On our bikes, the starting position of the TPS is pretty important since it's one of the 2 primary sensors it's using for fueling (unlike a car that's reyling on 5 or more sensors' feedback to provide precision fueling.)

So, in summary, I believe you CAN sneak air past the ECU. Since it won't register more air going in (no MAF) it won't move to another area of the VE (Volumetric Efficiency) map and/or timing advance map.

I welcome any technical corrections to the above, but I'm confident that the above is very substantially correct. For background, I certainly don't consider myself an expert, but I have built an EFI controller from scratch using a kit (MegaSquirt), where you solder the components onto the board, hook up your laptop and set all the variables, then start tuning the VE and ignition maps, including how much to compensate the fueling for startup (based on CTS sensor readings). I used the controller to run a 5.0 V8 (from a Mustang) that I put in a 93 Mazda B2200 pickup project truck I was working on. Without the wideband O2 sensor readings, tuning it would have been a nightmare. Without a MAP sensor (it didn't support MAF readings at that point), it would have been even harder.

wow. tl;dr



2010 TE 250 WSM: "M.A.Q.S. sensor (pressure, throttle position, air temperature) on throttle body."

Cool, thank you. I stand corrected on the MAP and IAT - it looks like they're 'built-in' to the TPS sensor. I'm used to seeing 'separate' sensors for each, not a single device incorporating these 3 functions. Again, thanks for finding this and correcting me on that part.

With no MAF, you're still going to be able to 'sneak' air in past the ECU. Since there is a MAP sensor, the VE table goes from being 2D to 3D and will be able to sense engine load.

no worries. I still think Cyclic needs more air (whether it's snuck in or not) or less fueling. I hoping that the cts does the trick, but I'm not betting the ranch on it.

what's the word- is he still around?

So my next step before we ride this weekend , now that i went leaner on CO1 and she seems to like that is to remove backfire screen from air filter box.
I think she is going to run good, puddles... will have to see if that effects me

So, I adjusted my CO1 to 97, CO2 to 102 and CO3 to 102. The result was a hanging idle (rev it up and RPM's would come down naturally to about 3000-3200 RPM, then 'hang' there (sometimes for .5 second, sometimes for several seconds), then finally drop back down to 2300RPM or so. In the end, it actually worked fairly well - if I chopped the throttle before, then went to get back on the throttle, it would usually bog. If I chopped the throttle now, it would usually 'hang' above 3,000 long enough that if I hit the throttle again, it wouldn't bog. However, if it did drop down to 'regular' idle speed and I hit the throttle, it may or may not bog (or just die). I tried some changes with the JD tuner - a hanging idle is usually a lean condition, so I tried richening it up a little. I didn't play with it long enough though, I just wanted to ride. This ride, oddly, the puddles seemed to have less effect on the my bike, but I think cyclic's experience was that the puddles were still affecting his bike (almost?) as much. I did have the bike just flame out/die on me much more often, and then often hard to start after. Can't wait until the TXC310 flashed ECU arrives (next week or so) so I can see if it fixes my fueling issues. Around 2:22 is a minor example of this, but I realized I didn't include in the video some of the more extreme examples (where I had to crank it 3 or 4 times to get it to fire, and sometimes had to pull in the cold start lever to get it to fire):
View: https://www.youtube.com/watch?v=_Lcmwprw4dQ&t=62s


Good example of cyclic's bog is from his video from yesterday at the 6:14 mark:
View: https://www.youtube.com/watch?v=iJnaLDA6AAQ&t=13s

He also slides off a bridge right near the start of the video. Very slippery out there yesterday.

hah- bet'cha you were happy that's on video!

hey, I gotta request- could you guys split this up in to 2 different threads? It's already kinda hard to follow who's who and what's what especially. And I get confused easy now that I'm in my 60's. Seems like every bike/thread in the Italian 4-stroke section is a TE250 or TE310 nowadays, too.