I got an 85 225dx. Itwill absolutley not idle nomatter what. This carb is basically rebuilt, ive taken it apart entirely three times so nothings wrong with jets, float, nohin. It perfect. It starts up ok and runs but when you let off throttle it putters down to shut off as if it ran out of gas. I can ride it fine until it heats up good 5 to 10 mins then if it dies it wont start again till its cooled off. Ive posted on several forums and have gotten no replies. Any outside input is greatly appreciated!
Thanks, Jacob

 

Maybe it's not carb related, even though it could be the wrong size pilot jet, or the wrong carb altogether? Some other things to check are the valve clearances, the compression, and the timing, I would go in that order. Your valves could need adjusting, the engine might be due for a rebuild, or the timing could be off 1 tooth. I think I have a service manual here for that quad(?) if you need some specs.

 

I'm sure you probably did this already,But maybe your idle screw adjustment is set way too low.....Maybe turn it up, and see if that fixes the problem.......

 

vent your fuel tank. is your fuel cap vented or does it have a vent tube on the tank or lid? it sounds like it could be a couple of items.
1. i know you said you cleaned the jets, but it almost sounds like the pilot is plugged-could plug off again if you didn't have a fuel filter or haven't changed it in a while.
2. vacuum lock due to the fuel tank not being vented.
3. idle adjustment has debris in it and not allowing proper adjustment.
4. as stated, wrong size pilot jet.
5. cable adjustment either on throttle or the choke is still somewhat engaged due to cable issues.

if it has a vent tube on the cap/tank, don't just think that it's not plugged. blow air through it to verify the tubing is clear.
i'm still thinking that the tank/fuel system is the culprit. it reaches equilibrium and there's no pressure differential and fuel ceases to flow after five/ten minutes. without the fuel tank vent tube or a vented cap, the tank will naturally vent after at least 30 minutes due to leakage around the fuel cap coarse threads.
that's the direction i recommend, go after the fuel tank vents. other items i listed are just to verify you didn't miss anything.
just food for thought.

 

Thanks yall for the replies finally!
Raptor450, I know its not carb related, thats why I posted this. I will try q new pilot jet, called yamaha dealer 2 miles from my house and its only 4 dollars worth a shot how would I know that the valves need adjustment and how would I check timing? I dont know much about the internals on this beast, ive worked , ore on cars than bikes. And its a thre wheeler.
Paulie, the idle screw changes absolutely nothing, like I said the carb was disassembled entirely and clean as a whistle thats why im confuzed about this idle problem.
Jaster, im pretty sure this doesnt have a fuel filter, or at least I havemt found it yet. Im considering buying one of those universal inline filters that goes from the peock to the carb. The choke was getting stuck before I pulled the carb off, it was even worse then but im certain its neither if those. And if it was a gad vent, why would it be nearly imposible to startup after a hot die? That is after removing the cap anyway to see if theres stil gas in it?

 

hey man sounds like you check the car about but what about the position of your needle it should be somewhere in the middle.just another quick look.and I know on a blaster when my rectifier went it would start but not run.

 

Which Needle the throttle or float needle?

Also, for anoyone who would know would the stator make a difference at all in this? I know electrical parts are heat sensitive.

 

a stator is basically your alternator. any atv is set up like your car or truck. think of it like that. the inline fuel filter should go between the petcock valve and the carb. if it runs and starts decent, i'd say your valves are fine. only a hard starting engine would 'maybe' need valve adjustments. it is possible you're vapor locking the fuel. is there insulation between the engine and bottom of the tank? the float is like the float in a swamp cooler or toilet, it controls the level of fuel in the bowl. he's talking about the slide needle. double check the choke operation and put in the new pilot jet. check the temperature of the coil pack next time it dies. see if it is blazing hot or normal/ambient temps. your stator should be fine.

 

I believe it would be your throttle needle because at the clip is too high on that needle and drop sure probably looked down which will close and not let a lot of fuel you should check with a clip it should be in the middle

 

Two things I ran into that cause that on my Big Bear. Run the ATV without the gas cap and see if its the cap vent not working.
Another was my ignition coil would heat up and quit but work agian once it sat and cooled down.