Help! Bike cranks fine but won't start.

[patrick_777]

He said he already changed the oil.

[DSmithjr]

Well, they're all good suggestions, but all to no avail. I'm very close to declaring this bike dead on arrival. I've changed the oil again, and this time it was only filled to the proper level where I filled it before. I've redone the carb again, setting everything I possibly could to the specs recommended in the manual. I've inspected the spark again, nice and blue and cleaning bridging a properly gaped plug. And after all of this... nothing. Not one little sputter, shutter, backfire, hiccup, burp, nothing. Just endless cranking over and over.

I removed the airbox and place my hand on the intake side of the carb while cranking the motor and I could feel a nice strong suction from the motor. I could literally see the carb pulling the starter fluid into the motor. It won't do anything. At this point, I'm not sure if it's getting fuel. The spark plug never gets wet with fuel the way it used to, but it should still at least sputter from the starter fluid. When the motor's cranking, I can place my hand over the tail pipe and feel the exhaust coming out.

As it sits right now I think it's one of two things: first, I got a compression gauge today but I didn't get the necessary adapter (I think it's a 12mm). I'll get the adapter tomorrow and check the compression. One of my friends told me he thinks it could very well be the compression. Second, I suppose it could be possible that the ignitor went bad and is sending out the wrong ingtion timing. I'm not sure if this is even possible but I guess it could happen :??: .

Anyway, all of the comments have been great. Please keep them coming. I will keep trying for awhile with this bike, and if I'll get fixed, I post about it here right away. It's beginning to raise my blood pressure to uncomfortable levels, and if I can't get it under control, I'll probably roll it out to the bulk trash pickup. Hopefully it doesn't come to that.

[music man]

Just going strictly off of what he is telling us, I am going to say that it doesn't have any compression, (or I should say not near enough) I guess we will find out when he checks it.

[Water Warrior 2]

Originally Posted by patrick_777

He said he already changed the oil.

My bad. Only read back a few posts to refresh my memory.

[Water Warrior 2]

This may sound totally off the wall but why not try something silly. Find a long fairly steep hill and coast down till you have enough speed to ease out the clutch and give the engine a real whirl without the starter drawing power. If that fails(probably will) you just need a friend and a truck to get back home. Or just tell me to shut up cause my mind is wandering in LaLaLand.

[DSmithjr]

That's actually not that silly at all. It's excatlly what my friend told me to do. He said he's seen bikes with low compression that wouldn't start on the starter but would start and run (not that well) by being push started. Granted, he said they were 2 strokes, but he suggested I try it out anyway. My problem is finding the hill. :biggrin:

[adrianinflorida]

Originally Posted by DSmithjr

That's actually not that silly at all. It's excatlly what my friend told me to do. He said he's seen bikes with low compression that wouldn't start on the starter but would start and run (not that well) by being push started. Granted, he said they were 2 strokes, but he suggested I try it out anyway. My problem is finding the hill. :biggrin:

A decent sloped driveway, with some runoff area at the end should suffice, especially if you have someone who can give you a bit of a push start.

[Easy Rider]

Originally Posted by DSmithjr

That's actually not that silly at all. It's excatlly what my friend told me to do.

I'm about out of ideas too but let's take one more whack at it.
Be sure your battery is fully charged on each attempt. Maybe even better, jump it from a larger car battery. The electronic iginition is known to be picky about low voltage.
AND after all this, I'd put in a new plug one more time.....just for grins; only about $3.

[Water Warrior 2]

Maybe just maybe. When there was excessive fuel going into the cylinder could the rings(especially the oil ring)be washed clean and lowered the compression ? A good hill could pump up the oil pressure and reseal the piston to the cylinder wall. Maybe 2 drops of oil into the spark plug hole before the hill test would help seal things.

[DSmithjr]

Well, someone also told me that spraying too much starter fluid into the motor can wash the cylinder clean as well and possibably have a negative effect on the rings. But I've got the bike project on hold for right now. I couldn't find the 12mm adapter for the compression gauge locally so I had to order one online. It will probably take at least a week to get here. I've been toying with the bike a little, but I'm really beginning to think I might have a compression problem. Could be stuck or gummed up valves, bad rings, or worse. Once I get the adapter, I'll be able to do a compression test and a leak down test if I do indeed have low compression. That might point me in the right direction. Just for fun I called a local Suzuki dealer today and asked them how much they'd charge to rebuild this little 250cc engine if I brought it in with bad compression. The guy said it would be around $1000 :lol: That ain't going to happen. I can't believe these dealers are actually charging people a grand to rebuild a little single cylinder 250cc motor. If it is a compression problem, I'll either have to fix it myself or sell the bike as is to someone who's looking for a little project.

I'll post the results of the compression test once I get the adapter.