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98 KX250 Kickstart woes

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So I recently picked up a 98 KX250 for a killer deal, The guy's wife just wanted it gone so I picked it up without to much discussion.  He did tell me that last he remembered it ran rough and had some issues with the kick start.

Cleaned the carbs (replaced jets), checked the cylinder, replaced cables, grips, chain, and a few other odds and ends.  Got it to start up fairly easily just needed to find the sweet spot for the air and idle screws.  I did notice the kick starter seemed to be slipping a bit, so I took off the right side engine cover and inspected it.. I found that the bracket that stops the ratchet was misaligned, and the post that it was suppose to fit over had sheared off, so it wasn't holding the ratchet correctly... at that time I just re adjusted the bracket to where it was suppose to be and tightened down the bolt... I thought I was good and took her out the track for the maiden voyage and on the 3rd kick the end of the kickstart shaft sheared off (I had noticed the end had already been 'twisted')... luckily I found a few people to help me push start her and was able to enjoy some time out on the track. 

When I removed the broken shaft I noted that the bracket had not moved, so either I installed it wrong or there is something else going on..

So I ordered a new kickstart shaft, and this time when installing I carefully drilled out the spot where the post was suppose to got and found an allen head bolt that fit snugly inside the bracket.  This time I took careful steps to make sure I installed the kickstart shaft so the ratchet arm was resting in the bracket, then was able to get the spring in its keeper.  So I though I was good.

I went to start it and man as I remembered before the amount of force to kick it seems really high, more so that 450s I've had the opportunity to ride.  It also would kickback if I didn't make it all the way through the stroke. I did eventually get it started and running decent.  The next day I was about to get the carb further dialed in when I noticed that end of the new shaft I just installed was already starting to twist, so I decided not to kick on it anymore till I figured it out...

This got me thinking, when I installed hotcams on my 250f I intially forgot to install the decompression attachment to the exhaust cam, and started considering it was timing related.  I'm still new to strokes but it seems like the timing can really only be set at time of assembly?  I know there is ability to retard or advance, which mine is set to the middle tick mark. 

So long story short what should a be looking at for a harder than normal kickstarts?  Could the exhaust valves be opening and closing and the wrong interval?  is there an easy way to check those without removing the motor?

 

 

 

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Picture of the flywheel/stator is with the piston at TDC is that correct? Just as the pickup aligns with the lead on the flywheel?

IMG_20170518_162651.jpgIMG_20170518_162659.jpgIMG_20170518_162727.jpgIMG_20170518_162928.jpgIMG_20170518_162939.jpg

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Crank bearings or lower end crank bearing getting close to seizing ?? That bike shouldn't take that much pressure to crank that's one of the advantages generally alot easier to crank than a 4t .

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11 minutes ago, Greenwrench said:

Crank bearings or lower end crank bearing getting close to seizing ?? That bike shouldn't take that much pressure to crank that's one of the advantages generally alot easier to crank than a 4t .

I hope not... any way to check ?

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9 minutes ago, twostroke-notbroke said:

Screenshot_2017-05-18-17-54-31.png

The guy that sold it to me gave me the shop manual to go along with it, and I have been re reading this page and others over and over.  When I took apart the first broken shaft it had like 3 circle clips above the spring, but everything else was correct

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I hope not... any way to check ?

Take the spark plug out and use a ratchet on the stator side and turn the motor over by hand and see if it feels nice and free

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Took the spark plugs out and it seemed to turn over nice and smooth. Here is a pic of the kickstart assembly, I've triple checked all the washers and snap rings are in the correct space per the the manual

Can anyone give me some advice to check the timing? I don't see much in the manual for timing, maybe I have found the right chapter...

.IMG_20170518_174757.jpg

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I found the timing mark on the fly wheel and it seems to me when the piston is at TDC the flywheel timing mark is a few degrees to the left of three marks on the stator cover, it seems very close though... watching the piston from the exhaust port I see the piston move down when I turn the flywheel a few degrees to line up the marks... is this normal?  it seems there only one way to put on the flywheel since it fits over the woodruff key?

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It's a twostroke man. No valves and looks to be timed at factory setting 

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Just now, Motox367 said:

It's a twostroke man. No valves and looks to be timed at factory setting 

there are exhaust valves though right?  of course not like four stroke valves, but they do open an close if I am not mistaken... my thought was they weren't opening soon enough making it that much harder to kick

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3 minutes ago, doubleClutch229 said:

there are exhaust valves though right?  of course not like four stroke valves, but they do open an close if I am not mistaken... my thought was they weren't opening soon enough making it that much harder to kick

No valves . Make sure you mix the gas with twostroke oil 32:1

Edited by Motox367

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There is the k.i.p.s valve and yes it is timed but unless you have taken it apart then that should not be a issue if you were having lack of power issues maybe but that's not the force of that kick starter binding up that's either that kicker assembly , bad bearings , or something with your gears like the idler/ clutch , goes kicker ,idler ,clutch ,crank ,what's stopping it ?

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5 minutes ago, Greenwrench said:

There is the k.i.p.s valve and yes it is timed but unless you have taken it apart then that should not be a issue if you were having lack of power issues maybe but that's not the force of that kick starter binding up that's either that kicker assembly , bad bearings , or something with your gears like the idler/ clutch , goes kicker ,idler ,clutch ,crank ,what's stopping it ?

Thanks, I did notice when I had it running the clutch was dragging a bit, maybe thats part of the problem.  It has a hinson clutch basket, and I did noticed upon disassembly that one of the washers was not in the correct place and corrected it... I'll re inspect the basket and gears

any thoughts to why the timing mark of the flywheel appears to be advanced when the piston is at TDC?

also is there anything special I need to do when installing the kips operating rod when bolting up the side cover?  it seems pretty straight forward, though the manual is quite confusing saying to use a 9mm spanner... I just used my fingers and was able to get the collar off the operating rod... maybe that's where I went wrong?  it seems that rod controls the exhaust advancer assembly, so maybe its not working right and not advancing the exhaust like it should....

Edited by doubleClutch229
add

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You don't worry about tdc on a 2 stroke , there should be 3 marks on stator put it at the middle line and be done with timing as long as your woodruff key is there and your set at that middle mark you are good

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23 hours ago, Greenwrench said:

You don't worry about tdc on a 2 stroke , there should be 3 marks on stator put it at the middle line and be done with timing as long as your woodruff key is there and your set at that middle mark you are good

Well I took my time and triple checked everything.  With the plug removed it seems to kick over very smooth with no binding, install the plug and it seems to bind up half way through the kick... I did notice that once I had installed the kick shaft assembly and set the spring it did seem to have some side to side play, so I took it back off and tapped the ratchet bracket with a punch quite a few times thinking that it had bent allow the kick shaft to move, it seemed to help but there still was some side to side play... how much play is normal for the kickshaft assembly with the side cover removed?  Could the slot in the center case that the kick start shaft fits into be damaged?

I managed to get it started and it ran pretty horrible over all, I was using 93 with motul 800 1:32 mix... though it could be the higher temps that we have been having...

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Welp I think I have a root cause... The slot that the kick shaft fits into seems to be damaged. I checked the play on an rm125 motor I'm also working on and there was almost no play, and the slot was a 'square' cylinder...

I guess my option here is to take it to a machine shop and see if they can bore out the slot and make a sleeve to get back to stock bore slot

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For those wondering the last post above is false. Once I installed a new idler gear the kick was much smoother, but still hard to start. Tried many different carb settings and the bike would start, but not after kicking back like hell through the kick starter (piston being forced the opposite direction).  Broke the repaired (stud and jb weld) kick starter I had in the process. 

So either: 

A) the CDI is bad and causing an incorrect timing situation.
or

b. there is pre ignition before the actual spark due to at 'hot' condition, amplified by the iron sleeve that is in the head?  Maybe try colder plug or race gas? I purchased the $7 oem plug and had the same result. Tried a new Ignition coil and everything.  

 

Anyone want to buy a cheap KX250 :ride:

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