MaximusAcordius

What's going on everyone!,
Just broke in my HPI F 4.6 engine on my Savage X. The next day I changed the glow plug, ran the car, and tuned the engine. I'm currently using Torco 20% with a medium glow plug.
Had no problems breaking it in and tuning. I made sure to leave it slightly rich since I will be bashing. After run maintenance was performed after tuning using 3-in-1 in the glow plug hole and WD40 in the crankshaft via carb opening.
The next day however, I was priming the engine and accidentally flooded the engine. I then attempted to un flood the engine and noticed runny black oil coming from the glow plug hole when I turned the engine upside down followed by the same black oil coming from the exhaust when I turned it back which had a somewhat fishy odor. I then started the engine, but noticed the engine kept dying right before it would shift into second. It was a hot day so I leaned HSN a bit to compensate which seemed to help a bit. I also leaned the LSN slightly but was still unable to run half throttle without the engine dying. When the engine dies, it made a sucking noise similar to that when you put your hand over a hand held car vacuum.
Frustrated, I went home and noticed the black oil on the floor in my garage. I then took the engine apart, cleaned it, and inspected the parts. One thing I noticed was that the retaining pin holding the con rod to the piston was loose. There was quite a bit of play when I move it up and down despite the wrist pins being there.

Can anyone explain to me what the black oil is, why one day the engine is running strong and all of a sudden barely runs, and is it normal for there to be play on the con rod and piston even with a brand new engine?

Jowers

iTrader: (6)

That is probably the 3 in 1 and wd40 making the black oil and fish smell. That is probably also why the engine ran great before then poorly afterwards. I would take it apart, clean it, reassemble, replace glow plug, replace air filter, and not put anything in it but fuel.

iplaygames

Standard 3-in-1 oil is fine inside the engine and will make it a little hard to start but will quickly burn clean. lots of people in cold parts of the world HAVE to use ARO to prevent rust from the fuel.
WD-40 is mostly solvent so it will of cleaned the carbon out, hence the blackness, clean engine out.. run it and when finished for day, run it dry and just use 3in1 as aro, take filter off and pour a decent amount in and turn engine over a couple times.. ta da no rust and no issues

mikesd1980

iTrader: (76)

IMHO i would not use ARO or WD40. Your 20% nitro fuel have 14% oil and that's should be good to keep internals lubricated till you run it next. If you do use it, i would only for storage for a couple months.