My daughter has a 1987 Savage with 11,888 miles on it. We bought it with 6,700 miles on it and to my knowledge there have been no modifications to it. We live in Ocala, FL (north central). I raced motocross in the 70s & early 80s and have a lot of experience with 2 stroke engines. I work on cars, have a lot of tools, including a multimeter, but electrical stuff is my weak area. My daughter and I replaced the plug under the head cap about 1800 miles ago and have seen no indication of leaking. The oil and filter were changed about 1500 miles ago. A different daughter needed transportation at college and took it to school. Several times she left the key in the wrong position and it killed the battery. I took and put a new battery in it about 2 weeks ago. While I was there I check the oil and it was almost 2 quarts low. There are no signs of leaking from the engine and no oil on the ground where she parks it. I put oil in it, started it and it ran fine. Last week she rode it about 70 miles and she said that a car turned short in front of her, she down shifted and then it was hard to shift up. When she did shift up, she said it made a crunching noise and quit. The battery is charged and it turns over without making any bad noises. I pulled the tank and watched the decompression solenoid and it appears to be operating correctly. I pulled the plug, it is black instead of the typical brown and it doesn't have any spark. I am looking for some guidance as to what I should be looking at next, Thanks.

There's no compression - none of this sounded like good news to me either.

When she down shifted to avoid the car she may have over-revved the engine. This can result in all sorts of issues with the valve train. I would start with a proper leak-down test to determine if there is a compression problem and where it is coming from, ie air from the breather is a ring problem and air from the carb or exhaust is a valve issue.

FLDoug wrote on 02/09/15 at 16:03:16:

I'm afraid she's probably dropped a valve.
you can take off the header and the carb to see the valves.
one missing or bent is bad news.

Hmmmm, 2 quarts low, crunching noises.. Sounds fatal,But,

Before you pull the plug,clean out the cavity it is in.
Then you can see if it's gonna live.
If you have to buy a can of air or Berrymans you can blast around the plug, pull it, add oil, pull the oil fill plug, blast into the cylinder, and if you feel it come out of the oil fill hole,the piston is not okay.

2quarts, that's pretty much all there is... just good she was not running highway speeds and sieze up. Could have been a lot worse than messing up a motor. Congratulations, you can hug your undamaged daughter and laugh about it.
SERIOUS learning moment. She got away with it. Anyone who has really run 2 stroke dirt bikes Knows about keeping a finger on the clutch, just in case it locks up, rarely do the daughters know that. Oil levels are critical, not just because of the small amount of lost oil that will ruin an engine, but also because a locked up engine equals a locked up rear wheel if it is in gear and the rider doesn't know to grab the clutch,, ugliness ensues.

FLDoug wrote on 02/10/15 at 14:20:15:


What is the compression release doing while you are turning the engine over?  If you have not disabled the automatic compression release before you hit the starter button (remove the small cable).....you most likely will not feel any compression at the spark plug hole.

Fellows I really appreciate all of your input. I disconnected the decompression cable and I still didn't have any compression at the spark plug hole. It did still push a lot of air out the exhaust. I removed the carb and looked at the intake valves. They are there (which is a start) and they appear to function ok when I turn the motor over.

I will try to get some air tomorrow and try both Justin's air test for the piston and Gary's leak down test.

Thanks again guys - I will keep you posted.

The ball and roller bearings on this bike are pretty durable, and do survive the low oil issues better than a few other parts.  The piston/cylinder being one area - the cam/rockers are the other.

Since the engine made a crunch and stopped....and now apparently has no compression, I would suspect the piston/cylinder may have become damaged.  It does seem a bit weird that this would have become terminal a while after the low oil issue, and the bike did run after you installed the oil.....I can't explain that one.....or why downshifting might have broken something (unless she just overevved the engine and floated the valves and bent them...which doesn't seem likely).

This one is just going to take some investigation to see what is wrong.