Question about running out of gas...

[mmz77]

Hi all, it has been quite a while since I been on here. Anyway, the last ride that I took my CR250 out on I laid it down on a hill and shut the gas off. After several attempts I finally made it to the top. Turns out about 15min later into the ride my bike seemed as if it was fouling a plug (and the first reaction I know if is to rev and clear the bike out a bit), well it was just that I forgot to turn the gas back on! :bang: My question is, do you think I might have damaged the top end in anyway? (I am sure this has happened to a lot of people over time). The bike still runs great and has good compression. The only thing that I notice that I'm not sure if it was there before but if I slow turn the bike over with my hand it feels kinda choppy through the compression stroke (doesn't get hard or hung up at any point), not sure if that is any indicator of damage or such but it kicks over smooth... I have about 25hrs on the top end currently and run Maxima Super M 40:1. Let me know what you think :whoa:

 

[arnego2]

While its not really good to run a 2 stroke with out gas due to lubrication it should take no harm from ones or twice, just don't do it on regular basis.

 

[mmz77]

Yeah this was the first time it ever happened to me. The bike ran out of gas and as soon as I had my new plug ready I looked down to see the gas was off. I was cussing up a storm knowing it was not good to let them run out of gas. When I finally turned the gas on, it started first kick no trouble.

 

[ws6transam]

I ran out of gas in July; well actually I had a fuel blockage. I was on the throttle hard; doing about 60 MPH through deep sand. It was 97 degrees out. The engine started to ping, then started to bog, and as soon as I felt the power loss I let off the gas and the engine locked up. My clear fuel filter was empty. I jiggled the fuel line and it started filling up again. However it was an hour before the motor finally released the piston, and another thirty minutes before the piston let go of the rings. So 90 minutes later I got it to start and was able to ride out of the federal forest. As a result, I had welded some aluminum onto the cylinder wall, and etched a notch on the edge of the piston due to lean-out.

So yeah- My question is, while running out of fuel, were you hard on the throttle? Did you experience any soft lockup? If not, you are probably okay. If you suspect that you did have a soft sieze, then you may want to pull the head and take a look at the bore for any scoring or deposited aluminum.

 

[mmz77]

I was just revving the bike because I thought I was fouling a plug. The bike just died as if I had hit the kill switch. I turned the fuel on and it started up first kick like it normally would any other time. I rode the bike for about 45 minutes with no problems to finish off the day as well. My only concern is, is that if this happened, does that always mean damage has been done?

The bike did not lock up one bit, it kicked over smooth after I turned the fuel back on...

 

[pesky nz]

My guess is no damage done as you didn't run out at full throttle and high speed and a hot motor and knife edge jetting.

 

[rmc_olderthandirt]

If you could ride for 15 minutes with the gas shut off then I submit that your fuel valve isn't working very well!

I have forgotten to turn the gas on a number of times and had the bike die with no damage. There is a significant difference between our situations, however.

When I forget to the gas on it is because I turned the gas off, which generally means that the bike had been not running for a while. This, in turn, means that the engine is NOT hot when I start it back up and it generally doesn't have time to get hot before I run out. Since I am normally just outside of camp (generally still in view of those who will heckle me later) I haven't even opened it up to get it warm.

In your case, you rode for 15 minutes, including climbing a hill that was causing you difficulty. This sounds like it could be a hot engine situation.

What's more, is that there is no way the carburetor bowl held enough gas for 15 minutes of riding. The petcock had to be leaking, which means that it didn't just run out, it ran lean before it finally died. This could be a worst case scenario.

If something doesn't feel the same, I would recommend freshening up the top end. If there is no damage then you are looking at a few hours of work, a set of rings and gaskets.

If you continue to ride it and the top end seizes you could be looking at a lot more $$$

Rod

 

[mmz77]

Yeah I'll probably get one done before next season just to be on the safe side. How does $350 sound for a top end? That includes new piston, rings, gaskets, etc and it is a local shop near me. That is labor included in the price. :nod:

 

[reepicheep]

If that includes a cylinder rebore and replate, that is awful cheap. If not, it sounds like full retail, and that's assuming it is a good quality piston like a Wiseco. $150 to $250 worth of parts, the rest labor.

I could do my KDX-200 (without rebore / replate) for about $200, probably over a long lunch.