Owned one for almost 13yrs now..... ;)

If you mean, why did the bike run perfectly? Well I bet it was down on power a bit. You can completely unplug the sensor (or somehow mange to miss plugging it back it....... oops) and the bike will run fine, it will just be a little "flat". Pull over to see if you can figure out why the bike is quite right, find unplugged TPS connection, hook it up and like magic the bike runs perfectly.... don't ask me how I know..... ;)

If the input value is outside of the parameters the ECU is looking for then it goes to a default map, which will keep the bike running but it won't be near as crisp in throttle responce.

thanks for the info guys. Somehow I just got it in my head that it should be turned clockwise and since I couldn't hold everything and get a reading that made sense. I really shouldn't be allowed to own an analog multimeter.

So i just went by feel, and you know how it is, sometimes it just feels really good. hahaha. And that was to turn it clockwise till I could feel the spring engaging and then held it there and used a selftapping screw to hold it there. Started it up and it never missed a lick, no more backfiring, stalling, sputtering, just smoothness. "What a fuckin hero super superhawk mechanic". Ran like that till we were doing steves' and he said he remembered that it should be turned counterclockwise. I couldn't believe it and it was only my extreme humility that let me accept this possibility.hahaha.

Seriously, it helps to have another person to check you, I mean, check on me. Now we're gonna help another Hawk owner steve met the other day. I'm thinkin of putting a sign on the garage, maybe something like "trial and error mod shop-pa nub"(that's eddie murphy term for "free". hahaha

PROCEDURE UPDATE:

There are some reports of the TPS popping off when the mounting screws are removed. To avoid this, do them one at a time. Remove the first old screw, then put in the new replacement screw BEFORE removing the second old screw. This will prevent the TPS from popping off.

JB

TPS
 

Hey guys, I've finally gotten around to changing the TPS on my bike, I've been following the guide so far without any problems, but I've run into a wall. I've gotten the airbox assembly completely off, and next would be to lift the carbs and take off the TPS, but I can't figure out how to lift the carbs. If anyone can help me out here I would appreciate it, cause I'll feel awful if I did all this work, and didn't even get to adjust the TPS (Plus I need to go back to hoboken some time tonight!).

-Mike

you do NOT need to remove or lift the carbs to adjust the TPS. Use a dremel to remove (grind off) the bottom screw if need be.

Tell Frank that we said thanks.

Ok, so in that case I would just need new bolts to replace these grinded off ones?? I'm trying to grind off the bolt right now, with a rotary saw dremel tip, still having some trouble....

i don't see the issue with undoing the two carb clamps and lifting the carbs up for a better angle. like resident said not ness, but easier i think. you can also get a small chisel and tap in loose, just don't slip and hit the tps sensor.

I used a dremel on the bottom when the top was removed the stub from the lower came out with my fingers. It may also be possible to thread the stub through the bracket. I'm a little hazy as it was 5 years ago. I know I didn't need the easy out or a left handed drill bit.

I have a pencil Dremel which made it pretty easy.

The advice regarding using a larger drill bit than the 5mm bolt is for removing the head. It works wonders. The next time you have a bolt strip (outer corners on hex, inner on socket), center punch and go with a larger drill bit(compared to threads, not head). When you have gotten all the way through the head, it starts to spin. Remove head and turn bolt out with vise grip or by hand. seems to work quite well.

And I would guess, this is what a "pencil Dremel" would be... It makes working in tight places quite easy...

that's weird looking. Mine is just an extension cable a couple feet long that accepts bits, cutting wheels, grinders, etc., and is powered by the dremel at the other end. You can hold it like a pencil. It's so much better in terms of access, accuracy and control that its never been disconnected since I first installed it years ago. In fact, i had forgotten that it was an attachment. hahaha

They come in a couple of different shapes... Mine is smaller than the on in the pic... And yeah, I hardly ever disconnect it...

ok, question about the TPS. On the back of it is the plastic thottle guide and the metal spring keeping it in tension. When I took off the TPS to put some wires on for easy access with the voltmeter, that whole back part came off. It looks like the plastic backing is supposed to be connected to the back of the TPS, like they rotate together. Does this mean I need a new TPS, or can it be fixed?

I really doubt you can fix that... Sorry, but it seems you are going shopping...

That was my fear... so far I've found it for $101 and $87 at the sites listed below... Let me know if you guys know of any good sites for buying oem parts.

www.cheapcycleparts.com
www.bikebandit.com

you might want to look at buying a set of carbs that includes the TPS.

http://shop.ebay.com/i.html?_kw=vtr&...essories&_ipg=

wow, thats absurd that I could buy the whole carb set for less than that damn sensor... the only problem there is again I don't have the confidence of working on the carbs, this is all new to me

If you take things slowly and methodically it shouldn't be a problem...

you could remove the TPS and sell the carbs and recoup your pesos.:D

I'll add my experience. Just did the adjustment. I took the tank and airbox off, left everything else in place. The TPS was at 907 ohms, and I could only twist it to 670, so I took it off (I just touched the multimeter leads to top two prongs, no need for wires and connectors).

Taking it off was pretty easy with a dremel, but I do have a pencil extender, which I think is necessary unless you pull the carbs (I left the carbs in place). I first tried to chisel the bottom bolt loose since it's a tight fit even with the pencil dremel, and I was NOT hitting it that hard, but the plastic "wing" with the bottom bolt going through cracked right off when I hit it. So be very gentle as the TPS can be brittle (mines 12 years old).

I thought I was screwed, but I got out the JB Weld as a last resort, and it worked to put it back together. I love that stuff.

As has been said before, small adjustments make a huge difference. I had to drill out the holes and got it to 540. Took it for a test ride after putting everything back together, and I couldn't tell a difference honestly. My bike ran pretty well before though, so I don't know what I was expecting to feel.

So my advice would be to do this adjustment if yours is running poorly at low rpm, but otherwise it might be wiser to just leave it alone.

I was thinking the same thing, leaving it alone. My bike also runs fine no hesitation at all throughout the rpm range, so I'm just procrastinating for a period.

Ok well I ended up doing mine today. Used a sharp flat-head and a hammer to knock them sheer bolts counter clockwise. Mine was set at 855 ohms I brought it down to 624 because it wouldn't turn any further, but heck I could immediately tell the difference on my bike, so much smoother in the lower powerband. Very noticeable and I for one am :)

Here is a photo of the TPS removed from the carburator. You can see the metal bottom tab that may need to be bent slightly to get the proper adjustment

Attachment 27293

FYI, you can do it without bending. I took out the inserts in the housing and used a round file to extend the slots. Replace the inserts and rotate until you get a low enough reading.

I did it this way too, very easy. I tried to bend that top tab in the pic above, but it's a 90* bend and didnt do anything. I bent it pretty far too, didnt really make any sense to me.

I believe you mean the bottom, left, rear tab needs to be bent slightly.

that's an ingenious method. We have some creative people here. Good thinking.

yeah, because you bent the wrong tab, but i like the way you ended up doing it better. Actually, if you bend the rear tab, it's only a slight bend to get it into spec.

^oh I get what you mean now, makes sense. I just stuck with the non-bending of things ;)


Question, does anybody know if this TPS adjustment is an alternative to the ignition advancer thing from factory pro? Aren't we in theory advancing the timing with this TPS adjustment just like the factory pro item does? Or can we gain more with the factory pro piece in addition to the TPS adjustment? 98 timing vs 02 timing?

Has anyone done this mod, and ended up having some major hesitations at low RPMS? My bike was having some major issues with surging at low speeds, and rpms. So, I did the mod, which fixed the surging, but now it seems to not want to rev up at low throttle, and low rpm. So, when pulling away from stop, I almost have to rev it up higher then normal to get it to go, so that it won't stall out. Also it seems to be doing more carb backfires. I thought maybe it had something to do with jetting, so I tried pulling on the choke while riding, and it made no difference at all. After the mod, it didn't start as good, idle went down from 1200 to about 800, so I turned that back up. It still runs almost exactly the same everywhere else in the power band. Just has nothing at very low rpm, and hesitates to the point of almost stalling when I just give it a tiny bit of throttle when it's standing still.

I know this mod changes the timing a little, so I'm wondering if my timing could be out? or can it be?

did you sync your carbs? you don't have a signature at the bottom of your post so we can't tell what's been done to the bike. Are you certain you got the TPS at the right settings? Did you have to bend the tab or elongate the hole? Give us some info here so we're not shooting in the dark.

Fixed signature for you. Yeah, positive TPS is set correctly. I got it to 497 ohm, but had to bend the bottom tab very slightly to get it there. Haven't sync'd carbs yet, still stock exhaust, but just put in the K&N. Two bros pipes on order, so I plan on rejetting then and removing PAIR at that time. The bike doesn't even have 2000 miles on it yet, so it's very new. I live at about 4000 ft above sea level, so jetting here is very different then most settings. I'm getting more carb coughing, or up drafting then before TPS mod, and K&N replacement. But bike runs great when I'm on the gas. Pulls smooth from low RPM as long as I give it enough gas. It's only having issues under low throttle input, or sitting at idle and bleeping the gas. It's stalled on me a few times, and coughs back at me a lot when doing this.

Not sure how much more info can help.. Anything else specific you need to know?

You know it helps if this discussion stays in one thread... It makes all of us a lot less confused... But it's up to you where... Just pick ONE!

Was the K&N in there before the TPS mod? If the K&N was installed at the same time as the TPS mod, try reinstalling the stock filter and see what happens.

Yeah, did them both at the same time.. So, yeah I'm going to try and put the stock filter back in and see what happens. Either that, or I'm going to put my slip ons on when they come in, and try to mess with the jetting a little, after doing a carb sync, and PAIR removal..

Looks like there's lots of pics here, but I'll throw mine in as well:

http://i918.photobucket.com/albums/a...h_P1190648.jpghttp://i918.photobucket.com/albums/a...h_P1190650.jpghttp://i918.photobucket.com/albums/a...h_P1190652.jpghttp://i918.photobucket.com/albums/a...h_P1190653.jpghttp://i918.photobucket.com/albums/a...h_P1190654.jpg

great pics moore. a couple questions/comments.

what caused that round mark on the slide(22-23)?

your supposed to pull those rubber lines out of the holes between the carbs for a reason I can't recall offhand (i think it's because they look too orderly all tucked away like that. haha). may cause a stumble i think and you wouldn't want to stumble would ya? what would your friends think?haha

why did you drill out the tps holes when you did such a great job slotting the rivets? I would have left the metal inserts in there and reused the rivets, but no big deal though.

did you remember to insert a fitting and rubber tubing into the bottom of the front carb for the quick carb sync which you will need to do shortly?

did you put a #48 pilot in? If you didn't, 8541hawk is gonna punish you boy. haha

just food for thought in case you may have missed something you didn't know about. great pics

You're gettin close to launching that rocket huh!

Well, since it's winter up here and my beloved VTR is hibernating away in my garage (and I recently finished re-doing the jetting to run an open airbox as per the specs kindly forwarded by VTR guru Roger D), I decided to tear into it again last night and readjust my TPS down. While my first experiment (a few years back, with the engine mostly stock) with dropping it down to @ 500 ohms had been largely inconclusive (actually, make that negative, as it seemed to soften up the engine response at low speed), my reading through various threads led me to try it again, especially as my engine is no longer stock (muahahahahahah). I opted to tune it down to 435 ohms (or as close to 430 as I could get it) based on various posts, including one by Greg (who recommended between 410 and 450 or so ohms) as well as the claim by (former member?) CTS moto that 430 was the magical number, based on the dozens of VTRs he had tuned.

Here's to hoping it turns out well this time.........

Yeah. I remember you noting that the 500ohm setting didn't help and i really couldn't say for sure relative to mine because i committed the the greatest crime of any good scientist, i.e., changing more that one thing.rot roh:eek: The funny thing, or maybe sad thing, is, I couldn't get a reading that made sense on the analog meter I had, so I decided to do it by feel. haha...It ended up that i rotated the TPS in the wrong direction until I could feel tension in the spring acting on the throttle. I thought, this is great, who needs a gage? At this time I also cut the airbox flap and cut out the paper filter(leaving the wire screen) and inserting filter foam oiled as per my dualsport). Of course I set the air mix and shimmed needles, sync mod, etc. Seems weird that so many people have reported difficulty with the K&N filter when the oiled foam works so well in mine and it seems like they would flow air similarly, but I don't know that for sure. So, put it all back together, TPS set by feel, and it ran like a raped ape, i.e., better than ever without a stumble, pop or any dead spots.

Anyway, a couple years later, i was helping Steve29 do his carbs and we discovered that I turned the TPS in the wrong direction and since I had purchased a digital multimeter, we were able to set his correctly. Then we were also able to get a reading of mine and it was over 2000 ohms if that's even possible.haha. So we readjusted mine to correct spec, but it made no detectable difference in throttle response, so who knows WTF is going on for real. Whatever, we know that there is always a real explanation for this type of magic, but i also do know one other thing, it worked flawlessly for two years. thankfully. haha

it'll be interesting to see how yours turns out at 430.

what caused that round mark on the slide(22-23)?

I'm trying a trick to get the front slide to open slower as per 8541Hawk's suggestion. There's a recent thread on carb setup that he started- It's explained in there

You're supposed to pull those rubber lines out of the holes between the carbs for a reason I can't recall offhand (i think it's because they look too orderly all tucked away like that. haha). may cause a stumble i think and you wouldn't want to stumble would ya? what would your friends think?haha

You're the second person to tell me no to do that. They're out now! The holes just looked like a perfect hose storage

why did you drill out the tps holes when you did such a great job slotting the rivets? I would have left the metal inserts in there and reused the rivets, but no big deal though.

My TPS was so far off that just bending the tab wasn't enough (no joke, 1190 ohms). I drilled the holes to allow the sensor to be rotated, creating what ended up being 499 ohms. I ended up putting the metal inserts back in after I drilled the slot out

did you remember to insert a fitting and rubber tubing into the bottom of the front carb for the quick carb sync which you will need to do shortly?

Nope- didn't even know this trick. I think I've seen pics of your $5 homemade one (was that you?). I'll go search for that thread later today

did you put a #48 pilot in? If you didn't, 8541Hawk is gonna punish you boy. haha

No local shops had them in stock, ordered a set from hollisterhonda. Pretty much everything is direct from 8541's advice- even the parts venue!

just food for thought in case you may have missed something you didn't know about. great pics

You're gettin close to launching that rocket huh!

It's been a long time coming. Parts are at paint, electrical only has a few more hickups... ohhh man my buddy just got a little Monster and I can't wait to show him the awesomeness of a Honda twin