Topic: Throttle Position Sensor

[ironman_stittsville]

I recently checked and adjusted my Throttle Position Sensor on my 04 Suzuki Bandit 1200S. I don't know if this TPS is common on your bikes.

The spec I've read is that it should be set to about 76% (ohm2/ohm1). It looks like mine came from the factory set at about 83 or 84%. Apparently this makes a difference in the performance of the bike. I noticed last year that it felt a little bit like the bike had a flat spot around 5,000 rpm and I've heard a little popping on the decel since putting on the Hindle and tuning the carbs.

I don't think I'm too rich because my plugs look a nice tan colour (as long as I have a clean air filter in there, doh!).

I haven't ridden the bike this week, I've been working on it (fender extender up front, hugger in back, headlight mods, oil change, axle nut replacement, chain adjust/lube, etc.) but I'm wondering if anyone else has adjusted this item and noticed any difference. From what I've read it can make a difference even if the TPS is off only 2%.

If I understand correctly, this TPS is used to modify the ignition timing based on throttle input. The TPS is a potentiometer (voltage splitter) that is connected to the butterfly valve in the carb, as the carb is opened/closed the resistance of this device changes and modifies the signal to the ignition system. The ignition system interprets this and changes the spark timing.

Anyone here done work on this?

Rh.

[rubberlegs]

being that I ride a KAWI I can't personally relate to improperly set sensors from the factory.

I very much doubt that changing the setting a few degrees will give you anything other than a diffrent throttle feel (if you are very sensitive)

you are right.  The TPS does assist the ECM in making ignition decisions but it does not do it alone. You have other sensors that work along with the TPS.  setting the TPS off by too much will cause a problem

I know some of the SV guys have benifited from better throttle response by setting their TPS correctly

[ironman_stittsville]

i wouldn't say i'm the most sensitive rider out there but i'll be trying to feel out the difference this weekend, time allowing. if it doesn't make a difference to the flat spot or the mild popping on decel, i'm not sure i'll notice it, nor care.

rh.

[skyshot]

I've read that the voltage output of the TPS on my truck should be .96V, and if it's above 1V it would make a noticeable difference.  Haven't checked mine though.

[menglor]

its something I know about that I can play with, but I have resolved to leave it as Factory as possible for a few months till I get used to how it was designed.

Then I plan to make it mine.

[ironman_stittsville]

i _hated_ my Bandit when i first got it because it was so crappy to ride when it was cold. the stage 1 carb kit i put in there has fixed that up very well. i did have to increase the air flow a bit though.

i noticed that the bike is less 'peaky' in it's power delivery which makes it much more usable on the street. the low end torque on the b1200 is ample but now it's just a little bit more ample and accessible.

i've made lots of little mods to the bike to make it fit me better, like right now i'm obsessed with better headlights. i think i'm going to have to replace these things this year. bad lenses or something.

rh.

[SVTom]

I doubt the TPS is affecting the bike at 5000 rpm.  If you're having jerky throttle syndrome at parking speeds then a TPS tuning might cure that.

Just our of curiosity, are you "cruising" at 5000rpm?  Or is the flat spot while on the way up the power band?

[ironman_stittsville]

i feel it while on my way up the power band.

i think it's the cct controlled mostly by the needle. i have the stock needle in there with some shims. i _think_ that my current needle has a single taper so ... I'm not sure why i feel this at 5000... perhaps i've got it wrong at at wide open throttle i'm into the main jet cct?

it hasn't been bothering me really but i have thought that i should fix this via a carb tune sometime. prolly next year (or late this season at the earliest). too many other cats to skin... whoops... did my inner monologue shut down there?

rh.

[rubberlegs]

yikes..

you guys are talking about carburators..................................

SEE YA!!!!!!!!!!!!!!

[SVTom]

i feel it while on my way up the power band.

i think it's the cct controlled mostly by the needle. i have the stock needle in there with some shims. i _think_ that my current needle has a single taper so ... I'm not sure why i feel this at 5000... perhaps i've got it wrong at at wide open throttle i'm into the main jet cct?

it hasn't been bothering me really but i have thought that i should fix this via a carb tune sometime. prolly next year (or late this season at the earliest). too many other cats to skin... whoops... did my inner monologue shut down there?

rh.

PM this thread link to Bandit_Phil.  He has an 05 Bandit 1200 and may have had some experience with this before rejetting that may have been cured by the rejetting.  I'll be talking to him tonight and I'll tell him to check his PMs.