I'm having some minor throttle sticking, just a little in the lower rpm, takes an extra second to return to idle every now and then. I haven't had much time to look into it but I did narrow it down to being in the carb itself, definitely not the throttle lever or cable, I took the cover plate off where cable connects to the carb to verify it. When the engine is off you can hear sorta a squeaking sound when you work the throttle, not a traditional metal to metal squeak more like a plastic or rubber squeak, I tried to spray a little lube in the carb but that didn't seem to help, I probably could have gotten it in there better and may try once more. Anyone else have this problem or suggestions, I'll probably end up tarrin the thing apart but was hoping for a easier way out or to hear if it may be a common problem with the z.

thanks

 

I had that problem when i first got mine. my problem was this little sensor by the carb that was sticking. its the throttle positioning sensor. i unscrewed it and messed with the turning thing inside and blew it out and oiled it with a drop or 2 and when it went back together it worked. i had the scratchy noise too and still do but no sticking throttle. i tore mine apart b4 i found this too.

 

Thanks for the help.

I took mine out tonight and sure enough it was the tps making the noise, it did however spin freely with no resistance so I don't think It could have been holding the carb open as the carb spring seems to put a good deal of return force on the little shaft that works the sensor. It had some sort of white grease in there for lube but It definitely could use some more.

So my next question is or I guess two questions would be how will the sensor affect throttle? It's been a while since I've played around with motors and I know a bad sensor can really mess up a car, to be honest I didn't even know the wheeler had one until I was playing around the other day trying to find the noise and noticed it on the carb, I guess I just assumed it was a real basic carb setup without electronics controlling or adjusting anything. So how does the tps actually affect the rpms or what does it electronically adjust? Secondly after I took out the sensor I noticed the screw holes are actually slots, I should have noticed this before I moved the position but was in a hurry and missed it soooo now I don't know the original position or it's affects of being in a different position, all I know is it must have some affect because it spins position causing the sensor to now not know where the original idle point was.

Can someone fill me in on exactly what the sensor controls and how to set it to the proper position, could this position also contribute to my rpms not returning to idle causing me to think it was a mechanical sticking problem while it actually was an electronic problem?

 

all i kno is that when i took it off, oiled it an put back on, it worked fine. i dont know exaclty its effect on the machine. i dont thinks it even needs it i started mine up with it off to see an it worked fine but i put it back on to ensure safety in long run. did urs stop sticking though cuz if so then its done an forget about it otherwise i dont kno what uyour bikes problem is.

 

I haven't had a chance to try it out to see if it's still sticking, probably tomorrow. I called the dealer yesterday to ask them about it and they told me there probably wouldn't be any "drive ability issues" if the sensor was incorrectly set however it would affect performance, from what I understand the sensor adjust ign timing to get the most out of the bike, they said I just wouldn't have as much power across the whole throttle range. They say it's real easy to set so just incase you want to reset urs here it is, all you need is a volt meter to check the resistance, with the bike off and the throttle closed he said take the wires of the tps and use the meter on the sensor, loosen screws a little and spin the sensor until it reads between 3.5 to 6.5 kila ohms, tighten screws and that's it. Also said to use dielectric grease to lube it.

 

Cool that they gave you the info you need to fix it.

Kinda got a chuckle about it not having driveability issues, just affect performance.

I thought performance is why we bought these, and that would make it an issue.

 

thats what i was thinking hahaha