Non starting XR 250.

[Pieeyedpiper]

Never have had my '97 XR 250 going since I bought it 2 months ago. Its a long term restoration project.

Trying to get it started is proving a bit difficult. I've never had any personal experience in XR's or any 4 stroke really, I was always into 2 strokes in the past, but there does seem to be something wrong with the compression when kicking it over.

I've read loads of threads about how to start them, and every bike seems to have it own peculiarities. When kicking over there is hardly any resistance until about half way through the stroke,then it becomes a bit harder. On about 1 kick in 6 or 7 there is real reistance, but only at about half way, not from the top. Then, you do get a bit of a wooom from the exhaust. I was expecting to have to put my full weight (about 13 stone naked) on to kick it over.

Is it possible that the decompressor is on?, I can't seem to get much freeplay at the cylinder head end of the cable. Or maybe the valves need to be adjusted?

I get a decent spark when the plug is out of the engine (Isn't fitting the plug a tw*t of a job?), and the plug does come out wet and smelling of petrol.

I'm at a bit of a loss as to starting it, but the compression doesn't seem right, suppose I need to get it compression tested.

[malwelder]

had the same sort of prob it seemed to be stale petrol so some hi octane unleaded did the trick but im a four stroke man so feeling for compression stroke is normal good luck hope this works mal

[kempouk]

sounds like you are missing a tooth from the kick-start spleen, just try holding the kicker in with your right hand pushing the spleen into the engine and then with the left hand see if you can feel the kicker engage closer to the top.
this is what happened to my bike, it was only engaging from about half way down the kicking cycle, the top half there was no resistance at-all.

have you tried towing the bike to see if you can get it to fire up, as you will only be getting half of the actual stroke that is required to start the thing.

i managed to find a way to kick mine and that was to get to the ignition stroke (where it goes hard) then just push the kicker gently down another inch to move the con-rod over tdc then bring the kicker back up again then try to kick it.

i find just turning the tick-over dial just a quarter turn clockwise helps to start the bike as well.

are you getting any kind of kick back at-all, if so that is where you aint pushing the kicker that extra inch once you have found the compression stroke.

let me know how you get on eh..

good luck

[Pieeyedpiper]

Thanks Kempouk,
you might be spot on the money about a tooth missing on the kick start shaft. I spoke to a local bike shop who has some experience with XRs. They said it sounds just like that and had it happen to a bike they had. Apparantly the shaft can come out without stripping the whole engine.
If not the shaft, they said it might be the bearing, in which case it is a strip. Mine has only done 2k and they say its irrespective of milage, just faulty bearings.

I will try the method you explained to get it to turn over and cross my fingers.

Thanks again for your help. Al.

[kempouk]

yes that is right, you don't need an engine strip but you do need to remove the clutch box to be able to remove the spleen to get to the missing tooth.
apparently the hardest part is re winding the kicker return spring, there can be some scuffed knuckles so watch out.

click this link, (4.6 meg .pdf) it is from the xr manual and shows you how to remove the kick start spleen. http://xrrider.web.officelive.com/Do...0kickstart.pdf

the file is i 3 languages so just scroll down to the UK language.

[Pieeyedpiper]

Well took the right hand engine cover off and inside found..... Nothing that I can see wrong. No broken teeth in the bottom of the casing, no obviously worn teeth, nothing.

There did seem to be a bit of end play along the length of the shaft, only about 1 -2 mm at most, and when taking the casing off the thrust washer wasn't over the hole, just slightly to one side. My first thought was someone had had the casing off and not put the washer back properly, allowing the end play.

The end play meant that the pawl teeth didn't engage straight away, but half a tooth later, which put the kick pedal half way through the stroke.

My next thought is this. As the bike is ex Army, a '97 with only 2k on the clock means that it has been stood for a good long while. Would this mean that the pawl engagement spring would be slightly compressed, not giving it enough power to engage the pawl soon enough?

I can get a second hand shaft complete with all gears, springs, washers etc for £35, but don't know if I need it or not.

Think I'm going to have to bite the bullet and get it into my local bike shop.

[Pieeyedpiper]

Met a fella a couple of weeks back, when I was buying a lift stand from him. Turned out he used to have a 400, and if left too long was a pig to start. An old chap who used to run BSA's told him to tip the bike right over to the left until petrol runs from the carb overflow. Stand the bike upright and he said it would start on the 3rd kick.
On my 3rd kick it spluttered, then with 4 more kick she fired up and ran fine. Smoked a bit at first then settled down, no smoking.
I think with being stood for so long the petrol in the carb had evaporated leaving an airlock!
Just glad I didn't have to pay a bike shop to figure all this out.
Now its running, its getting all stripped down for a re-furb.