Absolutly Stumped & Clueless....Need Help (long)

[jonnyriabov]

I winterized my 2004 yz 250 at the end of last season

-fogged the cylinder,
-drained the tank,
-cleaned the carb
-changed the tranny oil,
-cleaned and left the filter dry
-greased all the bearings
-and kept it indoors all winter (cold-hot mix of temps)

It was running perfectly without a flaw when I put it away....I went to get it running this week, and it started up perfect, and has its usualy awesome power, but.........It refuses to idle, and has a terrible bog when leaving idle, Infact it will run just fine with the choke on (only starts with choke when warm as well)

The only thing different on the bike this season is I added an Hour Meter.

I have so far to try and fix this problem:
-Recleaned the carb, all holes seem to be flowing freely
-Changed to a new spark plug
-Checked my reeds (look like new)
-Checked my TPS ohms (seemed to be fine)
-Tried two different batches of mix, just incase I over mixed the first batch of fuel.
-Put my stock silencer back on
-Swapped airfilters incase I over oiled the first

Im sooo confused right now, as the bike runs just fine past the bog, and no matter what I do with the pilot screw nothing helps. Could it be the cold weather.....-2, Is it possible my powervalve is stuck from the fogging oil,....or should I clean my carb for a third time? Could the TPS be messed up from letting it snap to fast when reinstalling the carb slide?

Anyone who thinks they can help....please reply as I really want to figure this out without bringing it into a shop.

jonny hard luck

 

[TimberPig]

It sounds like you still have a plugged pilot circuit. The fact it improves with the choke engaged signals that it is lean. Combined with the cold weather, it will make it very lean. You're going to have to recheck that carb, ensuring that none of the passages or jets is plugged. The airscrew won't make much difference if the pilot is plugged, or if it is dangerously lean from weather much colder than it is jetted for. The other possibility is that you could have an air leak that is leaning it out.

 

[jonnyriabov]

Ok, I recleaned my carb today, and took my time......Although it did improve....a bit, I think its just still way to freakin cold up here in Northern Ontario just yet for my jetting.....still alot of snow so ill leave it for a while

-I found no air leaks, boots are on tight, no tears in the boots, new twin air in place.

jonny

 

[nickyd]

are you pulling the pilot jet when you clean the carb? its recessed inside a cavity.

 

[AsheyYz250]

Check the air filter and silencer......I had a mouse nest in mine one year did almost the same thing.....now i got one of those covers that go over the air filter and also plug for the silencer

 

[jonnyriabov]

*yup....I dissasembled the entire carb except for the TPS so the carbs spotless

*freshly mixed new gas, of proper octain rating

*I have a used fmf turbine core II sparky I picked up last month on the bike at the moment, but I blew though it before I put it on, and there was no blockage. I just put a clean brand new twin air filter on the bike, and its oiled properly, but thanx for the suggestions

prob the weather...I hope

 

[FMF99]

yah on my 2-stroke it didn the same thing..then when it warmed up it ran awesome..personally I think you spent too much time and effor for nothing.

 

[rm_racer]

I would say its the jetting. I would either rejet the pilot or leave it till its warmer. A little off topic, but, did you get any snow up there today? We got about half a inch. :( I thought it was spring. :ahhh:

 

[killerdwarf717]

It is more than likely the weather! Try raising you needle jet by dropping the clip down a notch. betcha it improves! You will probably have to leave your jetting this way, as you have now improved the bikes breathing abilities with that new can, and filter!!!!