GoneRogue Posted April 28 Share Posted April 28 Hey all, Just got this tmaxx and the carb is spitting when I hold down the exhaust and turn it over. Here is a video: Im pretty sure it's not supposed to do this. Is the carb ****ed or something else? Thanks. Quote Link to comment Share on other sites More sharing options...
locky Posted April 28 Share Posted April 28 What is hold down the exhaust mean? Is this brand new? Quote Link to comment Share on other sites More sharing options...
markymarky Posted April 28 Share Posted April 28 Why are you trying to start it without the air filter on? Quote Link to comment Share on other sites More sharing options...
GoneRogue Posted April 28 Author Share Posted April 28 Plugging the exhaust to get fuel through the lines. No not brand new. Not trying to start it here just showing you the fact that it's spitting fuel from the filter, otherwise you can't see it. My other nitros don't do this Quote Link to comment Share on other sites More sharing options...
locky Posted April 28 Share Posted April 28 If the exhaust is blocked then some of the atomised air/fuel mixture will be forced out the carb due to the crank creating positive pressure as the exhaust port is blocked. Quote Link to comment Share on other sites More sharing options...
GoneRogue Posted April 28 Author Share Posted April 28 Hmmm but why does this not happen on my other nitros Quote Link to comment Share on other sites More sharing options...
locky Posted April 28 Share Posted April 28 Are you using electric starts on the others? Quote Link to comment Share on other sites More sharing options...
GoneRogue Posted April 28 Author Share Posted April 28 Yes, the traxxas ez start Quote Link to comment Share on other sites More sharing options...
Nitroholic Posted April 29 Share Posted April 29 If your fuel lines are full of fuel, and you block the exhaust outlet and spin over the engine, the overlap on the port timing will blow pressure back through the crankcase. It's only exit is the carb. Well...assuming your engine is properly sealed anyway. If your crankcase has a build up of fuel in it, say...from starting attempts or rich running, then fuel will spit back through the carb. the carbs on these things are very simple affairs. Just a slider or rotary valve really, to control the air flow. If your carb is at idle, there should be a small gap open for the air inlet, around 1mm or so at it's widest point. That means the air is going to come out under reasonable pressure. Enough to spit fuel. Take out the glowplug, turn the car upside down, and give it a few cranks with starter. Put a cloth down to catch whatever spits out. The previous owner may have had the car in storage with a big dollop of after run oil in there to prevent gumming or corrosion, or there could be a load of unburnt fuel in there. I'd give it a good clearout and see if it still does it. Quote Link to comment Share on other sites More sharing options...
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