Twobeers
Key Veteran
Location: Toronto, Canada
| More than likely while refueling or attempting to start it up you have inadvertantly flooded the engine and hydrolocked the piston (filled the combustion chamber with excess fuel.) As a result while attempting to start it up the nut on the crankshaft holding the fan in place has spun loose. This action will allow the crankshaft to move in and out and the connecting rods crankshaft pin will bind on the crankcase coverplate. Drop the motor out and grasp the fan in one hand and the motor in the other, if you have any in/out movement (don't let it get you excited.)that's what has happened. Remove the nut & the carburator. Insert a toothbrush handle thru the intake manifold to hold the crankshaft. Tighten the fan back on (its threaded onto the crankshaft) as tightly as you can by hand. Replace the nut (use a drop of 242 locktite on it) and tighten moderately. Remember this isn't a Ford V8 so take it easy on it.
This happens quite frequently to many beginners and the fact that it spun loose may have saved you from bending or breaking the connecting rod or piston. Chaulk it up as a learning experience. The next time you try to start it up and it feels that the compression is to high, close the fuel line, remove the glo plug and spin the engine over for a few seconds to clear out the combustion chamber of excess fuel. Get yourself something to close the fuel line to the carburator when refueling. I myself after having this happen to me twice in one week when first starting out in this hobby not to long ago decided that simplicity was the ounce of prevention that has worked for me. I got rid of all the "T" fittings on all of my R/C toys. I have onedoohickey for closing off the fuel line to the carburator. When I refuel I simply pull the fuel line from the fuel filter to the carburator and plug the line from my refueling pump to the filter and fill up that way. No more hydrolocked pistons.  |
