My first seize!

[jeffp83]

The dents on top of the piston are from the hammer job I had to do to get it out of the cylinder lol.

 

[Trip..]

That's not from running the tank dry. You have/had other problems that caused the seizure. I run 50:1 and I've ran out of fuel at full throttle many times and never had a problem. What does the plug look like?

 

[jeffp83]

Plug indicated a lean setting, which I thought was because of the tank drying up. This was after about 40 minutes of full throttle runs in 30+C weather.

 

[Deluge]

Yeah, I run my tank dry all the time, as well. Haven't seized an engine, yet. Gnarly pics, though!

 

[jeffp83]

Hmmm... was I running too lean or was it the darksoul/marine setup running too hot? I figured it was because I was doing 16+k on fumes lol. I've never blown a 2-stroke before.

 

[Deluge]

My guess would be too lean.

 

[Guest]

Too lean man. I run my tanks dry every outing. I don't like to leave fuel in them.

Sorry. I guess you have a good reason to upgrade.

 

[jeffp83]

Ok thanks guys. I just figured i ran it out and it burned up. It was running the same way for ages.

 

[jeffp83]

Sorry. I guess you have a good reason to upgrade.

thanks! On to my next engine. Lesson learned!

 

[Deluge]

Any ideas for your next engine?

 

[Obeast44]

Hmmm... was I running too lean or was it the darksoul/marine setup running too hot? I figured it was because I was doing 16+k on fumes lol. I've never blown a 2-stroke before.

That could have been a contributing factor. The DS heads are known to run a tad on the warm side.

 

[jeffp83]

I noticed the ds marine setup always ran hot but never ran into a problem until now.I did read some stuff about them not lasting long though. Anyways, i will put the blame on myself. I was thinking about going to a 4 bolt.

 

[Deluge]

I believe I read on HBF that DS uses thermal paste on their cylinders to improve cooling efficiency.

 

[jeffp83]

I did use thermal paste but there is a big enough gap between the heatsink and the cylinder that it wouldn't do anything at all.

 

[Deluge]

Well, that sucks.

 

[TerraKill]

that looks like a heat seziure to me, seen pistons and barrels go like that many times on MX bikes on very hot track days.(common problem my honda cr125, i need bigger rads on tht bike, or i got a blockage i cba to sort)

and if you was running lean aswell, well.....

 

[jeffp83]

I checked the settings on my carb (668) after I got it apart... just over 1.5 on the high and 1.25 on the low. I think that's around stock settings?

 

[Trip..]

Carb settings mean very little. You could have the needles out 3 turns but if you have an air leak, it will still run lean.

 

[Guest]

Yeah, that is the base setting which should be rich. Air leaks can also cause a lean seize.

 

[jeffp83]

Carb settings mean very little. You could have the needles out 3 turns but if you have an air leak, it will still run lean.

True... i'm kind of scratching my head now as to what happened. I am for sure that I didn't have an airleak as I know what the engine sounds like when that happens. Going to grab a new carb as well, just in case. Maybe I will just go back to nitro, this may sound crazy but i've had less problems with those little engines than I have had with gas (plating failures, gasket blowouts, bad bearings and now a seize) lol.