won't idle yfm200dxs

[friery@hotmail.]

Hi all i hope you can help.... first let me say i just joined this site and i think it's great......

My problem is with this yfm200dxs. I have been told it is a 1987, but i am not certain. If i try to start it, after spraying a small amount of starting fluidin it, it will start and run as long as i dont put a load on it or try to let it idle. It just won't start by itself....it used to run fine and then this started.....i have taken the carb off and on and checked and rechecked and cleaned it.....and nothing seems to help. I have not replaced any parts on the carb cause i dont want to do a complete overhaul until i am certain it is not something simple. i am pretty certain the carb is a model mikuni vm22sh but i cant find any marking on it to know for certain......now i think my problem is with the jets, particularly the low idle jet but it looks fine on inspection and cleaning i am uncertain if it has to be seated flush or backed out a certain amount of turns and the same goes for the fast or main jet. and the stop idle/mixture what is a good setting to start with for that??????

finally why cant i find any manuals for this unit...i find them for 86 and lower and like 89 and higher but nothing for the 87?????? what up with that...

sorry for rambling but any help would be greatly appreciated...thanx again

[edog]

Post a pic.

[TimSr]

Is this a YFM or a YTM? We have a separate quad forum.

The jets should be tightened all the way and snug. Its the external idle air screw that is backed out around 1 1/2 turns as a starting point. When you removed and inspected the jets, did you also blow carb cleaner or compressed air through the orifices the jets came out of, and make sure they werent clogged? Pay special attention to the pilot jet. After removing it, also remove the air screw completely and then blow something all the way through the orifice in the carb. Carb cleaner works good for this, as you can also see if its shooting back out at the appropriate exit points.

[friery@hotmail.]

tim thanx for the quick response......i am pretty certain it is a yfm....i did do all of that several times but nothing has made a difference i will set the jets full in and the idle air screw at 1.5.......any other thoughts??????

[bigredhead]

Just like tim said.. anything that gets enclosed in the carb that you canot adjust from the outside once bolted on.. usually goes in all the way ( soft brass strips easy.. don't go nuts on it ... Just bottom it out and give it a gentle squeeze )

Check your petcock ( the thing with ON OFF and REZ comming from your gas tank.. make sure it flows good.. if it can be taken apart to be cleaned.. do so.

Do you have old gas in it ? has it been sitting a long time ?

When it won't start.. and before you use Starter Fluid ( careful with that stuff.... you should not have to use that .. if you do.. something is wrong... find the problem ) .. remove the plug and check if it's dry or wet.. if dry.. your carb is still plugged.. get a moose rebuild kit.. cheap.. 15 to 20 $.. and replace all the guts.

If the plug is wet then it's getting gas. and might be weak spark.. pur the plug on the wire.. touch the top to the head and kick it over.. check for strong spark. replace the plug if it's very old or looks rough and rusted.. If the gas is more than a few months old.. remove the tank.. shake it up and dump the old fuel... get fresh gas.

Check the wires that ground the electricals .. clean/sand down the contacts to make a good electrical connection ( the Geek will be by shortly to tell you it's electrical... LOL ) But go over everything and you will find a problem eventually.

Valves might need adjusting.. but don't get into that yet.... that's a last resort.

I could come up with more ideas.. but that should keep you busy for a bit !! :lol: Good luck ! :beer

[friery@hotmail.]

hey thanx big red....................ok i am gonna print your post and go over it all. goin to niagra falls this weekend but as soon as i get back i will get right on it (after work that is lol). thanx again....

ps. i have a clear gas filter on it and it stay full all the time....but i will check the stop cock....thanx