Old Xr250

[jakescott]

I got an old 86 XR250 that will not crank over. Its not that it wouln't start, the kick starter gets jammed. I pulled the side case off and nothing looks out of place. I can also turn the crank with a ratchet no problem so I know its not seized. Has anybody ever run into this problem before?

 

[TobyS]

Check how the decompression cam is set up. It might be in the wrong place and jamming, or not lined up right when you put the case on.
-Toby

 

[jakescott]

I thought about that but I don't have any pictures to show me how the decomp cam goes in. Just to be sure, are you talking about the small cam that attatches to the inside of the side case cover and is seated over the kick starter?

 

[TobyS]

There is a cam on the kickstart shaft.It has an index dot on its outboard face. This lines up with a dot on the shaft. Also, you have to pull the outside lever counterclockwise a ways to get the case started. This is on my '86 XR250R.

 

[jakescott]

When I had the side case off, I put the kickstart lever on and tried to turn it over that way. It got jammed just like when the case is on. Is that normal or am I looking at a more indepth problem?

 

[bake]

I just finished fixing a xr200 with the same symptoms, my sons bike had sheared teeth on all 3 kickstart gears. If that is your problem you will need to split the cases.

Did you notice any metal bits in the clutch side case?

 

[jakescott]

No, I didn't notice any meatal at all. The inside of the motor is very clean. If it were striped teeth on the kickstart gears, I would think it would grind and still kick through, just not turn the crank. I'm going to open it up again tomorrow morning, and take another look at the kickstart cam. Hopefully I'll find something out of place. I'll get back to you.

 

[njskiatomic]

Myself and a friend of both own 1986 XR250s, and we both had the same problem. I rebuilt his, but I haven't looked at mine yet, but I think my bike has the same problem. It may be common with this year. The problem with the bike that I rebuilt was that the timing chain had stretched and the chain tensioner could no longer make up for the slack. Because the timing was off the piston was hitting the valves and jamming the kick start. Later the kickstart would not jam, but there would be no compression. I had to replace:

Timing Chain: It was stretched
Chain Tensioner: It couldn't make up for the stretch of the timing chain
Valves: They were bent from hitting the piston. I think I probably replaced the valve seals and springs. No sense in using the old ones. Replace them when you have the motor apart.

Piston: The piston may have been good, but it had a big dent in the top of it where the valve hit it. From experience, it's easier to replace these parts than to rassemble the engine and realize that you have to take it apart again.