Echo SRM 2400 won't stay running

[cylon]

My echo srm 2400 only want's to run with full choke on for a few minutes then dies. Tested with spark tester and has spark while dying. Have already rebuilt carb twice. No air in fuel lines when engine quits. Since it only wants to run with full choke it has to be getting air from some where. Is this most likely a problem with wear around the front and rear oil seals in the crank case allowing air to be sucked in?

[hardboiled]

You may have bent the fuel inlet lever during the rebuild, upsetting the operation of the diaphram(fuel pump) and inlet needle. This happened to me on a stihl blower. The pump end of the lever was to be set at level with the surface of the carb body. I had unknowingly tweaked it ou of adjustment, causing the same running symptoms. You might look at that if this only started after your carb rebuild.

[cylon]

It started before the original carb rebuild. I think I'll have some fun with it and run it on model airplane fuel until it blows up and then buy a new one.

[RRS]

Sounds like the carb is on backwards. Seriously!

[bobbo]

The carb has a bushing on the throttle valve . this becomes worn and lets air in which makes it run real lean . only runs with choke. if you rebuilt the carb and changed the plug and filters that may be the probblem.. Will it run on 15% nitro fuel???

[cylon]

will run on 15% nitro only when diluted with gasoline. Those gas powered 2 stroke trimmers running with nitromethane will produce so much power it's scarry to hold one in your hands at WOT. I have NEVER used nitro in this particular trimmer. Carb is in perfect shape and will not go on backwards. The rubber oil seals around the crank shaft ends in the case housing look worn (part # 13 page #3 doc SRM-2400 Type-E on Echo's web site showing parts diagram).

[bobbo]

Im gonna have to try that one day

[TRANSMAN]

If you experiment

Im gonna have to try that one day

Try running in both clockwise, and counter clock-wise directions...

Most 2 strokes should run either way...

TRANS........

[cylon]

A Cox .049 Glow engine will run both ways but the nicer R/C 2 strokes have a rotary valve under the carb that is cut into the crank shaft so they will only run CCW. I dont think the Echo 2 stroke will run backwards because the spark plug would fire after TDC instead of before TDC. All things considering, I doubt it could run, not to mention the difficulty of spinning the engine backwards in the effort to try and start it.