start and get going probe

[rider58]

03 yz250f feels like something is dragging it down as i start to take off, and now can't get it started at all.

it was sitting for awhile so was going to start it the other day,after it started seemed like it didn't want to idle,but it would rev.

Put it in gear and it just bogged it down and killed it and after a few more trys it won't start at all now.

Also if i put it in gear and pull in clutch it won't free wheel. Now while trying to kick it over it feels like something dragging down the motor.

 

would like some input/help on where to start to look

Edited January 25, 2016 by rider58

[ronbuell]

Sounds like clutch adjustment or worn clutch basket.

When you start it in neutral, does it act the same way, or are you starting it in gear and holding the clutch lever in?

You should be in neutral for start up.

[rider58]

yes doing start up in neutral

yes acts the same way ,trying to start it in neutral it seems like the motor is dragging.

When we kick it over it goes though the kick stroke but thats it ,it doesn't keep rolling the crank.

Which if I'm thinking right the motor should roll over a bit more because the clutch assembly will be acting as a flywheel with the bike in neutral.

i have adjusted the clutch and when i say with it in gear it won't roll with the clutch pulled in ,it will not disengage clutch while rocking bike back and forth.

Found that out when we were going to try a bump start.

[ronbuell]

Could be several things, so I'd say its time to break it down and have a look see.  Simple fix would be a loose part dragging against the crank or flywheel or clutch.  Could also be the cam caps were tightened down too tight if you recently had the valve cover off checking valve clearance.  

[rider58]

thanks

We opened up the clutch outer cover and pull the clutch pack/plates they look good and no excessive wear on the basket.

Bought the bike used and seller said he had the top end done a few rides ago and by the looks of it i'd say that's true , the

base and head gasket look new/replaced. Don't know how far they went into it.

Also we rode the bike on two outings and it ran fine ,then it sat for about 6 months and now this trouble.

Hour meter that came on bike reads 190 some hours.

[ronbuell]

Well, to me, a top end is everything above the base gasket.  If the plating in the cylinder has worn off, that could be your issue.  Sometimes that doesn't show up on a tear down until its worn thru.  Another item to check would be the piston pin on the small crank end and bearings on the rod and crank.

[rider58]

Are the cylinders on the 03 plated ?

Also yes sounds like I need to open it up more, if the cylinder or a crank bearing was bad I should be able to put it in gear ,pull in clutch and it should roll- free wheel.

I was wondering if water pump or oil pump gears can cause a binding of drive or clutch gear.

[ronbuell]

Are the cylinders on the 03 plated ?

 

Yes, all years.  Its very thin, and the only way I know to measure is to put the piston in the bore without the rings and measure with feeler gauge.  Spec is in the book.  You need to measure at several places vertically in the cylinder and you need to check the top of the cylinder for a ridge, which will indicate the original plating depth.  There are companies out there that will re-plate, or you can buy new.  If its actually worn thru the plating, you should be able to see the aluminum in the cylinder.

 

On the water pump oil pump qu, I don't think they would provide enough resistance that you could feel it.  Only failures I have seen is broken water pump gear and scored oil pump and gears.  There is too much mechanical advantage on those gears from the crank to provide resistance.  They should be inspected, possibly replace water pump seal or bearings, and oil pump gear rotors.  Good luck with it.

[rider58]

thanks for your input ronbuell , I was just checkin if anybody else had this kind problem or if this is a common problem so i can narrow down where to start looking.

But i know I need to tear into it , just haven't looked inside these new age 4strokes much.

I'm thinking a bad bearing- crank or clutch/trans. Don't know if they did anything to crank when top end was done.

Got a shop manual on the way just for the measurement specs ,a person can't beat/do without a good shop manual.

Sure we can tear down and put back together easy enough ,but without specs we're just spinning  wrenches.

thanks again