Jan 01, 2003, 09:02 AM
Re: Nearly another 'how to tune my engine' question
Thanks for your great help...see in body of text below....
"Mr R. Laramee" <firstname.lastname@example.org> wrote in message
> ok its like this there can only be one thing wrong with it.
> let start from the beginning and work from there.
> 20% good fuel not something been setting for a year!
Fuel is about 2 months old but I have bought some new stuff - will try the
new stuff ASAP
> ok check plug.
I have changed the plug once (for a Traxxas plug) and it did not seem to
make a difference. The new plug did foul up quick though. Or at least I
think it did, what should a good plug look like? I could try and post a
picture of the plug in the binaries if it helps.
It does glow anyway!
> check fuel line free from crap and residue pin holes.
Fuel lines replaced to prevent any pinholes
> check fuel line going to exhaust pipe make sure its fitted properly and
Made sure the split pipe was not leaking/loose, and changed the tubing from
the pipe to the tank.
> check fuel tank (this is good possibility) make sure o ring makes good
> around lip of opening. no cracks in tank or anything that could impede its
We might have something here - there is possibly a crack in the top of the
tank. I know it sounds funny but its a bit difficult to decide if it is a
crack or not. I blew a small compressor into the tank from the fuel nipple
and blocked the pipe nipple with my finger and the lid popped off! Seems not
to be leaking air but I will replace it anyway since I have one.
> make sure the plug has its copper seal ring in place and tight enough.
I assumed this to be OK because the compression was good. The copper ring
looks undamaged too.
> next. start engine and look for fuel that may be coming out of a spot like
> anywhere it should not,
> eg, back plate to crank case, front bearing( this is anther good choice),
> head, glow plug.
After a run today there seem to be no leaks on the engine, carb seal front
bearing etc but the tank did seem a bit "wet" with fuel on the outside -
perhaps the tank is leaking...
> if it all checks out my friend that only leave one thing!
> that there is something wrong inside and the only things that can go
> inside are the piston, piston rod, wrist pin, crank shaft, ballbearings,
> lastly the liner. that's it for the engine end.
Oh no! Not inside the engine. Would I be looking for scoring/play in the
engine? In my (short) experience bearings will tighten/sieze or break up so
should be easy to spot. Would I see wear on the piston or the sleeve or
would it be too small to see?
> as for the carb look to make sure all your needle valves are well still
> needles. and that the crab is still under seal that's it for the carb.
The carb seems in very good condition and is sealed OK to the crankcase, in
which case I hope the fault is with the fuel tank!!
> good luck
Sounds like I might need it...
Funny thing is though it ran perfectly today for about 45mins non stop
showing non of the previous symptoms.
I will probably leave the things as they are for now to see if it has the
problems next time I use it with the new fuel. If they come back I will
change the tank and see how it goes. I would still like to know what it
was/is though - I don't like it when things mend themselves.