XR help and valve adjust ?

I have a 2001 XR250r that has always been hard to start. All stock. The first ride this year, the bike was hard as ever to start, then kept dying on me. I ran the carb dry before I put it away, but figured that it was from bad gas. I pulled and cleaned the carb and also wanted to check what jets were in it.

Stock 132 main, needle on middle clip, pilot set per the book.

While I was at it I adjusted the valves. One exhaust was very loose, the settings called for .004 and .005 but I didn't have that shim, the thinnest I had was .006 so I set them all to that for now. I plan to buy a shim, .135 main and new plug this week and reset the valves.

The plug looked good, running lean but no build up. Set the gap,per the manual and the plug is the standard plug per the book.

I put it all together and it still won't start for crap. The bike feels like there is almost no compression. I can kick it 6 or 7 full strokes slowly and never get a good compression. Then for no reason it will firm up.

I have read a bunch of tips/tricks for kicking the bike over, my trick is to once I get the good resistance, kick slightly to move just past TDC and then give it a good kick with no gas. When it was warm and I got the resistance, it started.

I have the manual decompression adjusted and even unhooked it. I kick the bike slowly to find TDC. How do I check to see if the auto decompression is not hanging up? I am thinking that this is where my issue is.

I know that there is a 150 page thread on ADV for XR250s, but every time I start to read thru there I waste 2 hours and wind up on craigslist looking for XR400 forks.

also, when adjusting valves, I always adjust them so I can feel slight drag on the shim as I pull it out and lock the jam nut with the shim still in place. But when I pull it out, I can never get the shim back in. Is that normal? Or am I tightening it too much?

You wan't light drag AFTER locking everything down, I like to check by inserting one size down and one size up after.

If you can't get the feeler gauge back in, you've got it too tight. Locking the jam nut does change the clearance, you've got to compensate for this.

Erratic feeling of compression indicates a problem with your decompression thingie. By their design, they can get goofy and out of whack under the valve cover. I'd suggest watching it there. It can also be a problem with a sticking valve. Again, watching the action under the valve cover would help identify this.

You can't kick a bike over past tdc slightly with any accuracy. It'll tend to go flinging right on past.

Generally speaking, you want to spin the engine over as quickly as possible when kicking over. A little initial resistance tends to help achieve that. That's why the general kick start instruction is to bring it up to compression, then kick it over.

foxtrapper wrote: A little initial resistance tends to help achieve that. That's why the general kick start instruction is to bring it up to compression, then kick it over.

Hmmm. That makes sense now. Never understood why that was the preferred technique!

In reply to doc_speeder:

Also makes it easier to use the stand on it technique. Ratchet the lever at the top of its travel till you get into compression, then put all your weight on the lever, easier on the leg.

OK, I got some new feeler gauges in the correct thickness, readjusted the valves. It starts better, but I still have issues finding compression on the kick starter. I can kick the bike slowly 8 or 10 times and still not feel any compression. Then for no reason, there is compression.

I unhooked the bar mounted compression release cable. There is no mention of adjusting the auto-decompression mechanism in the Honda service manual. No real mention of it during head reassembly and noting in the back of the book.

Online all I can find is how to remove it, which I don’t really want to do.

Also – the manual lever – I can’t adjust it to the point that the manual states – there should be a few mm of free play at the lever. Playing with the cable at the cam cover – I can’t get ANY free play.

Also – the manual states to make sure you are at TDC on the compression stroke when adjusting the valves or manual decompression lever. That seems to be the mistake I made the first time, I think I was TDC at 360 degrees later.

Decompression is either manual or automatic, not both. The automatic type is connected to the kick starter. The manual type is connected to a little lever in front of the hand grip.

If you're getting inconsistent bumps on compression I'd say you've still got a problem with your compression release. As I recall, I had troubles with mine, overadjusting it and causing it to flip inside the head, holding the valve down (no compression) except for those few times it fliped the other way and gave me compression. Take a look inside the engine at it, it's pretty simple, and clearly understood after a moment of looking.

With the manual system, you want it to be free and clear and full compression unless you pull the lever. Then it should hold the valve open slightly.

Similar the automatic, though it's timed to the pulling action of the kick starter. Again, enough slack to let the valve fully do its thing. Lightly keep the valve open when actuated.