while riding the bike just stopped, no wierd noises, just stopped running. stroking the kick-start is too easy, like there is no compression. I removed the valve inspection cover and they move as they should. i removed the side cover and noted that all gears are rotating, so the T-chain is ok. i pulled the spark plug and the piston moves up and down smoothly. I ordered a compression tester kit, and a boroscope (to see inside the combustion chamber through the spark plug hole) but they won't be in till the Snap-On tool guy delivers them in a couple of weeks. In the mean time does anyone have any suggestions as to new ideas or directions to pursue in diagnosing this issue? (FYI: the XR250R is a 4-stroke dirtbike)
2006-09-30 15:28:46 · 5 answers · asked by Anonymous in Cars & Transportation ➔ Motorcycles
Could be a holed piston.
A thumb over the spark plug hole will tell you if you have "some" or "no" compression.
"no" compression, without any accompanying clanks or clacks makes me think the piston has a neat hole blasted through it (from detonation).
However, it is a Honda. Never heard of them doing that.
Does this engine have the weird gizmo that lifts one of the exhaust valves when you kick it to make it easier to start? If that was stuck open that would explain it.
Seems like if the timing chain had slipped enough to cause this you would be hearing awful noises.
2006-10-03 20:21:16 · answer #1 · answered by SLamBob 2 · 0⤊ 0⤋
Well, sounds like you are on the right track, tracing it down.
Due to kicking it over being so easy, sounds like a broken piston rod. Sometimes it will still push the piston up and down and still be broken. Sounds like a compression issue.
As you know only a few things make an engine run.
Gas/air/spark. compression, timing, correct carb settings.
2006-09-30 23:15:07 · answer #2 · answered by Anonymous · 0⤊ 0⤋
pull the exhaust pipe off see if you can see the piston that way? use a flash light look in at the piston threw the clynder maybe a broken ring? other wise did you see if maybe you blew a hole in the top of the piston? darn should have said maybe a blown head gasket as well
2006-09-30 22:37:58 · answer #3 · answered by hackstudio 4 · 0⤊ 1⤋
check for spark, then check for compression by kicking it over with your thumb in the hole, it shold blow it out. Then check and make sure it has fuel getting to the cylinders. It should run if it has all three. :)
2006-09-30 22:37:00 · answer #4 · answered by Anonymous · 1⤊ 0⤋
i just had a 86 in the shop for the same sounding problem and the crank had broke on it.
2006-10-01 08:49:22 · answer #5 · answered by space_cowboy 2 · 0⤊ 0⤋