I thought I blew it up today !!

[Tin Lizzy]

started the coach today to put in shop and finish off my new square headlights. Let it warm up and then tried to move it. I think the wheels were frozen to the ground as it would not move. I gave it a little fuel and slipped the clutch a little to shake it free and then all hell broke loose!! Engine took off like a scared rabbit and I am sure the rpm's were maxed out and then it died.
Left it for 15 mins and then tried to start it. It started again with o problem and idled perfectly.........??
What in the world happened?
I had this a couple times before when I touched the gas paddle while the fast idle was on and it raced and died but this time no fast idle.
Does anyone have any suggestions?
thanks
Harry

[luvrbus]

2 strokes will build up excess oil and fuel if not driven under a load just turning on the fast idle won't burn all the fuel and oil and they take off big time

[Barn Owl]

I'm not an expert on this matter but I will throw this out there and see where it lands. Could your engine be drawing and running off of its oil that has seeped in it from somewhere? Possibly bad blower seals? When all of the excess oil is gone then it shuts down. My brother one time owned an old VW diesel, it would collect oil in the intake/air box area and every once in a while the oil build up would cause a run away condition. When this condition occurred that car would lay down a smoke screen that would make James Bond proud. When this happens with your DD, there is nothing that can be done to stop it unless you activate your emergency shut down. That little VW didn't have one so you just had to hold on and ride it out. Am I blowing smoke here or what? Anyone else have any ideas?

[DavidInWilmNC]

I had this a couple times before when I touched the gas paddle while the fast idle was on and it raced and died but this time no fast idle.
Does anyone have any suggestions?
thanks
Harry

When my MC-8 is on fast idle, the throttle pedal is pretty much disabled.  As soon as the fast idle is switched off, there is a 'bump' in the throttle pedal and it will function normally.  I guess one could push it, but it sort of locks out and I've seen no reason to fight it and break something.  Perhaps whatever keeps my throttle from being active is letting yours slip and hanging up somehow?  I don't think I described this very well, but I do know if you're on fast idle, you shouldn't need to press the throttle.  You also mentioned 'no fast idle'.  Mine requires the air to build before fast idle will kick in.  If it only happens when you're on fast idle and push the pedal... it's kind of like "Dr, it hurts when I do this!"   

David 

[Tony LEE]

There may be two air cylinders associated with fast idle. One that connects with the injector rack and one on top of the engine that locks the throttle linkage. Both need dismantling, cleaning and lubricating to keep them moving freely. If the linkage lockout one sticks and the throttle is depressed then the engine will race -- although it probably is still limited by the governor setting (). Even if the throttle is not depressed, the revs will gradually build up and up well beyond the fast idle setting.

Applies to my DD 8/71 in an MC*