Throttle Position Sensor check/adjustment

[MtnEX]

I have a service manual, and I've read through the section a few times, but it is very wordy and not pictorial at all....

So I am sort of lost, but I have a gut feeling that tells me something is wrong, and it is likely the TPS.

Mine doesn't start well at all, and it sounds to me like it has a faint miss at times... and according to what I have been reading, mine stalls easier than it should.

I guess I should have a look at the plug first too... but any input is appreciated here.

[k4f5x0r]

break in process/when theyre still pretty new they are hard to start. i say keep waiting a little while. mine was a ***** to start for the first few months. now it starts alot easier. and also with dead cold starting use the high idle. starts faster and warms up faster.

[KFX450Rrider490]

yea hes 100% right and u may want to turn up ur idle in general (misses when stabbed)

[MtnEX]

Well I read that article from the mechanic here...

I tried the 22 click thing... and then realized he sort of said it backwards... and then slowed it down 22 clicks from max. It's some clicks lower than I set it by ear. 22 clicks down is a slow idle for me.

I'm already using the choke thing on cold starts. I can't tell if it is really a choke or a single click to max idle speed.

Anyways, if I hadn't known about the knob, I would have never gotten it started from cold.

Hot it will crank back without it, but is stubborn. It seems like turning the key off then back on helps... I don't know why.

I'll wait it out a little longer though.

[k4f5x0r]

i never changed my idle. i might fool around with it this weekend just to see if it really makes a difference.

high idle for all cold starts then let it warm up till the exhaust is hot. then normal idle. and ride it around a bit. then i get on it hard. i wanna make sure that everythings nice and warm. so i dont drop a valve :eek2:

[Sprks450r04]

i let mine warm up until the left side of the cylinder is warm to the touch, then i know its ready to be beat up:devil:

[MtnEX]

Mine does not seem to be getting better to me.

The starting is about the same, and the flutter or miss at idle is still there.... And I swear the stalling issue is worse.

I'm ready to check it... I have a meter here, and I'm going to look for my tach.

I understand the process, but I was hoping to find better pictures to have a better idea of what I'm looking for.

[KFX450Rrider490]

when you ride for any amount of time to make the motor warm and shut off the quad will it start cause mine wont and it is doing the same thing with idle(all over and misses) this is the second time this has happend to my bike the first time it happened the tps was bad now it happened again so that could be ur problem

[MtnEX]

Mine is stubborn to start cold and hot... more stubborn cold though...


If it was bad-bad when hot... I'd be screwed.... because stalling is my more serious issue.


I think I might ought to check over the whole system with the meter after reading over some of the service manual.



It even sounds like it can be something as stupid as a low battery.

[MtnEX]

I did find some pictures too... and they are here somewhere in an article, but I actually saw them on quad-zone
.

[MtnEX]

OK fellas... I went to do this today... and I checked the battery first as I read to do.

The voltage was low, so I went to crank it and check it running....

Well, it wouldn't start... battery dead!
That is just my luck!
Reads 11.0 Volts


So what is the deal?
Never properly charged?
Just needs charged already?
Needs replacing?



Also, could this thing with the battery be my whole problem?

[spincr4hire]

update your battery to a Honda 450ER battery, Yuasa YTZ-7S, its the same width and length, just shorter. A lot more CCAs though.

[MtnEX]

Do you know what the CCA ratings are on them?

I ended up charging the stock battery up, but I had in mind to call my friend at Interstate Battery to see if he could help me find something strong that will fit. I've been impressed by their batteries.

[MtnEX]

Well, I got the battery charged up, and it seemed to hold it, so I put it back in to see how it went.

It's about the same as it was the time BEFORE I found the battery to be dead.

Cranks the same and stalls the same, so I am going to have to look deeper....


For now, I killed it with the kill button while in neutral and set the parking brake.
I'll check it Sunday or Monday to see if it's draining.
If not, I'll assume killing in-gear did the deed to the battery.


For the cranking and stalling, the next step will be checking the EFI... starting with the TPS.

But I have to figure out how to get to the dang thing!
Any tips?

[MtnEX]

Has anyone here actually checked their TPS?

If so, I could use some info on how/where to get at the wiring with my meter.

The dang TPS is behind the frame and the wiring is on the bottom of it.

[Sprks450r04]

i did mine yesterday, the manual tells you to use a tps check plug that you can get from your dealer that plugs inline with the tps, but i made my own way to check it. i took the throttle body right off the bike to do it but if you have that plug all you have to do is remove your left upper motor mount and its right there

[MtnEX]

Originally posted by Sprks450r04
i did mine yesterday, the manual tells you to use a tps check plug that you can get from your dealer that plugs inline with the tps, but i made my own way to check it. i took the throttle body right off the bike to do it but if you have that plug all you have to do is remove your left upper motor mount and its right there

There are two plugs in the manual...

Sensor Harness Adapter
Throttle Sensor Setting Adapter

Of course you would need the throttle one... and the way the manual reads, also their meter? I guess you could figure out how to use a regular meter in the end of the plug.

I thought about calling to see how much this plug is and if the dealer is even willing to sell it to me. Some won't sell you stuff like this.

Myself, I would rather let the shop go over the whole thing for me... but then if I did, I would have a hard time trusting they checked it all and did it right.

[Sprks450r04]

the dealer will sell u one, and the meter thing u use a meter and put it on DC system voltage should be 5 volts (ish) and then u have the other #'s for input and output in the manual