Hello all.

I have discovered that my Hawkeye has a throttle position sensor in the throttle lever assembly. What is its purpose? My quad will die like you shut off the key if the contacts of the TPS (throttle position sensor) are closed. I have adjusted the cable so that the contacts stay open so it will run, but if the contacts close, the engine immediately stalls.

Even if you don't have an answer to my question on why it's stalling, some info on it's intended purpose would be helpful.

Also it is having a hell of a time ideling even with the contact open. It seems to be ok off idle, although somewhat low on power. I have removed and cleaned the carb well. It really wasn't dirty at all. It almost seems to be worse after I cleaned the carb. Also found the bowl vent tubes completely blocked. Opened them up and didn't help. Runs much better with the choke on. Barely idles with the choke off after its warm. Won't idle at all with the choke off when it's cold. I have messed with the idle adjust on the carb with no effect.

thanks! PS I am an ASE certifed Master auto tech, but don't have much technical data on ATVs. Seems that info for this Hawkeye is sparse to say the least! thanks for any help you can be of!

 

welcome to the forum. the ETC (eletronic throttle control) is actually a throttle override to prevent the bike from running if the throttle was to get stuck open. it should be set about 1/8" gap(throttle cable that is). some 06's had a carb update done on them to help the running of the bike. maybe check w/ a dealer w/ the vin# to see if that bike is on the recall list. just an idea to start.

 

ok good. so you are saying that if that throttle position sensor contacts close, the engine is designed to stall? and I was right to adjust it so that they stay open when the throttle lever is at the idle position?

 

I called my dealer with the VIN and they said there really isn't any recalls so to speak, he said there was a bulliten that has something to do with the carb but it's for warmer temps and high elevations, and rich running... exactly opposite of what I'm dealing with.
Hawkeye running lean!!! HELP!!!!
My 06 hawkeye is running very lean. won't hardly idle without choke. backfires badly on deceleration (sometimes on acceleration) and in neutral I can wide open throttle and it gets about 2/3 through the RPM range and just Boggs down and will stall unless I let off the throttle. then it will pick back up. I can goose the throttle as many times as I want and it will rev but backfires occationally, but if I just hold it open, it revs, then bogs as if it's running out of fuel and will stall if I don't let off the throttle.

It seems to have good fuel flow out of the fuel hose at the carb. I've removed and cleaned the carb, slide looks good diaphram is good. Slide moves up when throttle applied, goes back down when let off. No jets or needles have been messed with at all to my knowledge (it ran ok before and nothing has been moved or changed since then) except removed to be cleaned and reinstalled.

Could a spark plug cause this? I really wouldn't think so. I can put my hand over the carb (as if choking) and it will run very well. Also runs better with the choke on. This is frustrating me as I own an auto repair shop and am very good with cars, but I just don't have any service info on ATVs and any help would be appreciated! I have family in for the holidays and we wanna go riding!!! If you need any car info, (specs, wiring diagrams, etc.) I'll be happy to help if I can!

oh yea, and I called the dealer about a recall and they said there were none for my VIN and I have cleaned out the bowl vent tubes (were severely clogged) with no change

 

it's not a throttle postion sensor like in say a car. its more used for when the throttle cable is too tight or when the throttle is stuck wot. pretty much yes it's designed to shut down the bike if you keep on the throttle. wasn't sure about the bulliten for sure so it was worth a guess. pretty much ifs running lean(guessing you know what it means and what causes it) then you need to start looking at carb(which you said you cleaned) and make sure the float is set correctly and no blockage and if it's jetted rich enough for cold weather. make sure the air filter is in the air box and it's not getting more air then it's supposed too. also make sure there it isn't sucking any air say form a bad seal, carb boot or any other place that would cause a air leak, which can cause a lean condtion. we'll keep this post only going for these questions instead of running more then one post.

 

Yea, I know all the usual stuff. I was just trying to see if there was anything out of the ordinary that is common to the hawkeye that someone who messed with em all the time might know that I wouldn't.

It is backfiring as well which on a car is usually a sign of a lean running condition or obviously a timing problem. I doubt it's timing. I'm not real familiar with how the ignition system works on atvs, but I'm not buying the timing thing as I can make it run better with my hand over the carb or the choke on when its all put together as I can't put my hand over it when its all together. I'm just stumped as to what's causing the lean issue. All the obvious stuff checks out. I haven't changed the spark plug yet, it actually looks quite dark colored... contridictory to the symptoms... A new plug should be in tomorrow morning and I'll try it then and report back. I'll also check for air leaks around where the intake boot bolts to the jug but i don't suspect to find anything.

Does anyone have a compression spec on this machine?

Keep in mind that right now the ATV is inside my shop and it's heated so it's not cold. I am at about 1200 feet above sea level.

Could it be a valve problem? when I try to run it without the air box on, I can see fuel sometimes spit out of the carb. not alot, but some. COuld this be a valve problem or is this normal? Most of my experience is with fuel injection. I have limited experience with carbs, although I do have some.

It just seems like it should be so simple and I usually don't get my *** kicked like this when it comes to machines!!! I gotta get this figured out. thanks for any further help anyone can be of!

 

also....

what about the fuel pump? I read on another thread about how to test it, but I'm unclear on the exact procedure. I should imagine that if I took it apart i could figure it out. Can you explain how it's supposed to work?

You prolly saw on my other post that if I hold the throttle wide open in neutral, it will rev to a certain point then bog and back fire until it dies unless I let off the throttle. every time I take the carb off, there seems to be a significant amount of fuel in the bowl, but I haven't actually measured how much.

 

it has a built in rev limiter. that is why if you hold it to the red line level it should act the same way as when the throttle override is on, by making the bike start to run like crap and die. this override is and redline is done thru the timing i do beleave to prtect the engine from an over rev. w/ the air box off the bike it should run worse for sure as it's designed to have that much air restricktion. there is no rebuild kit for the fuel pump so think of that before you take it apart and the gaskets get messed up(just a thought). i'm assuming the crank vent is all clear and open. not sure about compression(i dont have amanul to look at, but maybe someone does for ya)but would be at 110 psi. if not i would want to check the valves to make sure there adjusted right and closing. hopefully you can get this straightened out and let us know. good luck.

 

Did you clean out the main and pilot jets on the carb, inside the bowl? Sounds like the pilot jet is plugged to me, you need to remove it and spray carb cleaner and compressed air through it to make sure its clean, how old is the gas in the machine.

 

yes, I have removed and completely dissasembled the carburetor (jets and all) and everything is clean. Fuel is about 3 weeks old. The rev limiter won't disable once the RPM drops below the cut off RPM? In cars, the engine will kinda bounce off the rev limiter. This thing just bogs and the RPMs drop until it dies or I let off the throttle.

I would like to learn more about the fuel pump operation. I've read another thread that infact does mention a rebuild kit for the fuel pump... but whose to say for sure. Haven't had time to go searching yet.

also something else..

there is some sort of quite loud knocking noise in the engine/trans when its about to die or running at extremely low RMPS. sounds like literally sounds like soemthing is knocking around in there. It's kinda freaky how loud it is. Its been doing that for awhile so I never paid attention to it. I'm not sure if it's detonation or actually something kncoking but its only at low RPM like right before it stalls. drive or neutral dosen't matter.

I'm bad about overanalyzing things. I hope I'm not overlooking something stupid... I don't think I am, let me recap what I've done so far:

symptoms:
won't idle without choke
very low power
runs better with choke on
WOT in neutral bogs down until it dies unless throttle is released.

1. fuel 3 weeks old
2. removed, dissasembled, cleaned carb (twice) including all jets
3. runs better with choke on
4. removed plug looked black (contridictory to the symptoms)
5. checked air filter ok
6. fuel in the bowl when carb removed for cleaning
7. nothing messed with on carb settings (all stock to my knowledge)
8. cleaned bowl vent tube
9. crankcase tube not blocked


something else...

I followed the fuel line from the shut off valve to the carb and see no filter. am I missing it somewhere? thanks everyone for you help so far! We'll get this thing... sooner or later...