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Old Dec 30, 2002, 09:12 PM
n/a Posts
Re: Nearly another 'how to tune my engine' question

The clacking sound makes me think either the piston and sleeve are worn, or
the con rod is trashed.......

"" <> wrote in message
> Hi all,
> I really need some advice on this.
> I have 3 Traxxas nitro cars, a Rustler, 4TEC and of course the TMAXX. All
> have the TRX 0.15 engine in them.
> The Rustler runs great - very fast very powerful - it is also the oldest

> 3 years old...
> The 4TEC is not bad - but seems to have (and always has had) huge amounts

> compression compared to the other two - once running it tunes in and runs
> very well, it is just a bit of a pig to start sometimes.
> The TMAXX though is odd. When I first got it (about 9 months ago) I could
> run it all day with no problems at all, I would have said it was the best

> the 3.
> It now starts very easily and will run quite well for about 5 minutes. It
> then starts to sound as though it is running hot (clacking sound, uneven
> tickover) and the water drop test suggests that it really might be a bit
> hot. To compensate for this I richen the mixture (top end) and obviously

> makes a difference to the power, but does not seem to cool the engine down
> and I still have the uneven running at tickover. I have tried adjusting

> bottom end mixture instead and all I do is get a truck that will stall if

> accelerate too hard and is still hot. The basics of this problem are if I
> set it rich enough to keep cool the thing has no power and splutters like
> mad.
> The driving I do is a mixture of high speed and low speed - not that this
> seems to change the symptoms.
> All the engines were run in the same and exactly as per the instructions.
> So far I have done/ checked for...
> Dirt in the fuel line
> Dirt in the carburettor (disassembled and cleaned)
> Damage to the mixture needles
> Dirt / damage in the engine (not disassembled - just looked for score

> on the piston and crank)
> Ensure the air filter is clean
> Leaks in the fuel line etc
> Binding gear train
> Binding clutch (at tickover)
> Avoiding driving on grass (not that I have done this much anyway)
> Reset to factory tuning settings and start again
> I use 20% blue thunder fuel in all the cars and wonder if fuel is
> contributing to the problem (not that I have had any problems before), but
> why would it work in the other 2 cars?
> Sorry to post another subject on 'how do I tune my engine' but I am

> very frustrated with this now.
> Please, please help me with this, it is spoiling my fun!!
> Thanks
> Garry