Excessive engine rpm's when running out of fuel

[mackmanj]

I have a 76 Suzuki TS100 that i recently got running. I have noticed that about 15 to 20 seconds before the fuel tank runs out of gas the the engine revs up excessively until the tank runs out. It revs to the point that it almost runs away with itself. After you refill with fuel it will run fine until it starts to run out of gas. I,m afraid to let my kids ride the bike because i'm afraid they will run it low on gas and it will run away from them. This is my first 2 Stroke bike and i'm still learning all the little tricks of it. Is there something I missed when i cleaned the carb. It starts and runs fine as long as you keep the tank topped off with gas. Thanks for your help. Jay

 

[_JOE_]

That is normal. You need to keep it from running dry.

 

[2strokerfun]

It's just Mother Nature's way of telling me I'm a really, really a far distance from my truck and fuel can.

 

[Someone]

I don't think that's good for your engine either, I believe it creates a very lean condition when you run out of fuel.

 

[russdaddy]

ok cool my KDX does this too i was hoping it wasnt anything serious,its a bitch to shut off though even with the killl switch.

 

[dirt bike dave]

ok cool my KDX does this too i was hoping it wasnt anything serious,its a bitch to shut off though even with the killl switch.

That's because things in the combustion chamber have gotten so hot, the motor is self igniting what little fuel it is getting, and it no longer needs a spark from the plug.

The good news is a motor that is over-revving due to an extremely lean condition is not going to make much power, so putting the brakes on and dropping the clutch in gear should kill it instantly. The bad news is that without lubricating oil and cooling fuel, you can damage things in a hurry.

 

[mackmanj]

Thanks for the input. I have ran 4 strokes for years and this is my first 2 stroke. I'm learning that there are different characteristics between the 2 styles of engines. Makes for a good learning experience for my kids and me. Thanks again, Jay