All -

I posted another thread a few weeks back (I think?)
about my wife's 2006 SP450 will NOT run.

Summary Symptoms:
- It will start with choke pulled out
- If I throttle with choke out, it will cut out
- Can't start up normal, it sounds like it is trying to
kick over.
- It will stay idle (Rpms up and down, idling fast then if
normalize will cut out)
- Starts right up with choke out, no hesitating or backfiring
or spitting,

Things done so far:
- Multiple attempt to run Quad with choke out.
- Replaced SPARK PLUG today (the old was really
fouled) Checked gap and my new one, all good there!
- Put Dry Gas (eqivilent) into gas tank, whole bottle,
gas tank half filled with fresh gas. (I should of filled up
the whole tank?)

Thats all to date, I spent a good deal today trying
to fix her, BTW getting the Spark plug out on these
450s is a real pain, but I did it. So I would like any
input or guidence to help me with this situation.

Regards and thanks for all the help!

R'

 

doesn't that have a fuel pump? i had this prob on a go cart and choked the engine would just berily suke enogh fuel in to run but if you gave it a lil gas it would cut out. there is proba pump that runs off crank case presure of intake pressure something like that i think my 500 scrambler 2001 with teh sportsman engine and carb has noe right up front buy the ratiator under the front plastic withe teh wireing i also have my fuel filter up there idk were teh sportsmans run there stuff i havn't wourked on them much. I would change the fuel filter it sounds like you don't have enogh fuel. the fuel pumps are prob suction fuel pumps and they prob have rebuild kits all there is is lil check valves and diaphrams that go back and forth to pump the fuel. and yea i just checked my scrambler and i have a suction fuel pump up front it is rebuildable i see teh seal tab on the side and the screws on the top there are 3 black hoses going into it. one is the suction hose that powers it one goes to the fuel tak and the other to the carb or the injector eather way you have a fuel pump. idk if the suction runs off of the air intake pulse or teh crank case pulse. i have seen both types. the pulse linecould be crimped pinched ripped. or your pump might have to be rebuilt.

 

mine's 2 stroke not sure if it will work for you. when i got mine the person before me that owned it ran old gas in it and gummed the carb up.i went through 2 cans of carb cleaner still no help.i had to tear the carb completely apart and use very fine steel whool and carb cleaner to polish the entire inside of the carb.ran fine ever since but if the gas gets more than 3 days old i drain it out and get new gas when i get ready to ride again.is your involved in the ecm recall?

 

<div class="FTQUOTE"><begin quote>Originally posted by: sjbr549

mine's 2 stroke not sure if it will work for you. when i got mine the person before me that owned it ran old gas in it and gummed the carb up.i went through 2 cans of carb cleaner still no help.i had to tear the carb completely apart and use very fine steel whool and carb cleaner to polish the entire inside of the carb.ran fine ever since but if the gas gets more than 3 days old i drain it out and get new gas when i get ready to ride again.is your involved in the ecm recall?</end quote></div>

yea like sjbr549 if it is a carbed modle yous should first try to drain the carb at the boal then you could take it apart and clean it. i had my 1998 400l sport 2 stroke sit for a hole year and ran fine. i onece had water in teh fuel so i drained the tank but that was running and reving just spitting and sputtering like crazy. yours sounds like a lack of fuel i would think fuel filter carb or pump. start with fuel filter walmart $1.50 easiest to do. then carb because it doesn't cost anything but alot of time taking all of teh body pannels off and on teh scrambler fuel tank to get to it. idk about the sportsman tho. on my 400 sport it is easy just take the seat off air intake box and outside clutch cover and you can have teh carb off.

 

Check the valves.
1st symptom is slow rough idle.

 

was the problem all of a sudden or a slow? the valves would be a slow loss of power ofr floating at lower and lower rpms. unless something broke and if it broke it probably woulldn't run.

 

The idling up and down (RPM) is usually a sympton of a vacuum leak. If it will idle at all, try spraying the carb base, and any area where the carb joins the manifold with wd40. If the idle changes, you have a leak in thaat area. Tighten any bolts or screw concerned and try again. Hope this helps .

 

<div class="FTQUOTE"><begin quote>Originally posted by: sprinter10

was the problem all of a sudden or a slow? the valves would be a slow loss of power ofr floating at lower and lower rpms. unless something broke and if it broke it probably woulldn't run.</end quote></div>

hes had this issue only since it sat over the winter and first starter it up. i would guess valves are just fine. imo.

 

this may be completely wrong for you......... but mine made almost the same amount of trouble one day last year and it ended up being the throttle cable needed adjustment.

but you said the plug was fouled. Fouled black, was it wet or dry? Fouled plug means it running rich. not enough air or too much fuel. correct?

 

yea brut that is right and i pmed the big guy and gace him that same idear. the fouled plugs are i think because hes running full chocke at idle and it wont take long to gas foul them.