User Manual

Run-in the engine
- Follow the cold start section as below
- Idling with throttle on radio in neutral position:
o Engine idles well; this is the case if the car does not roll for-
ward
with the engine running and the throttle in neutral > leave it as
it is.
o Engine stops when in neutral > Adjust the idle screw
with ¼ of a turn in (clockwise) at the time, and start again;
repeat as needed
o Engine idles too high; in this case the car moves forward
with throttle in neutral > Adjust the idle screw with ¼ of a turn
out (counter clockwise) at the time until the car does not move
forward anymore and engine idles well
- Run the car one tank of fuel with this setting. When you run
the car apply max 70% of total power and do not run at 70%
or more for longer than a few seconds.
- After 1 tank of fuel, screw in the high speed needle
1/16 turn and run it for 1 tank again.
- Repeat this 5 times in total. Do not lean out the engine too
much, as this will cause overheating and breakage.
1/16 turn out (anti-clockwise) is the minimum necessary.
- Run the engine with same setting for another 5 tanks and
apply max 90% throttle .
- After the 10 tanks in total the engine is run-in and can be
run at full power.
Cold-start
- Make sure the fueltank is lled to 90% with a high quality
commecially available rc car fuel with 25% nitro.
- Perform 5 pulls with the pullstarter without using the
Glowstarter and closing the outlet-pipe of the exhaust with your
nger, this will allow gas-mixture to enter the engine
- Apply the glowplug starter and pull the pullstarter with
short fast pulls.
- As soon as the engine runs, then lift the car up and apply
short strokes with the throttle lever of your radio to warm up
the engine. Remove the glowplugstarter.
- Mount body-shell and start running the car.
- Try to avoid the fueltank from going empty during the run.
A tank of fuel will last between 10 and 15 minutes, so refuel
before it’s empty, so you continue driving without restarts.
- To stop the engine, press a proper engine stopper with
rubber top against the ywheel from the bottom of the chassis.
NEVER use your ngers!
Hot re-start
- Apply the glowplug starter, apply a little bit of throttle on
the transmitter, pull the pullstarter few times until it restarts.
- If after few pulls the engine does not start then let it cool
down for 5 minutes and try again.
- In case it still does not start than follow the instructions
in section: Engine does not start.
Setting the carburetor for best performance
Follow the section: start the engine (cold or hot re-start)
1. High speed needle setting:
- Adjust the settting with max 1/16 turn in or out per time.
- After changing the setting apply throttle few times with car
of the ground, to allow the engine to adapt to the new setting
- Run the car again and check carefully the result.
- By turning-in the needle (clockwise) the engine will run leaner
(will get less fuel) and the speed will increase, if you lean the
engine too much, the engine will run too hot and damage if
continued too long. If the engine runs too rich (too much fuel)
the speed will go down and the engine may shut down, as the
plug cannot ignite the gasses anymore.
- You can also check the correct running with an optional
infrared temperature gauge; optimal temperature
is around 100˚C.
2. Low speed needle setting
- Adjust the settting with max 1/16 turn in or out per time.
- After changing the setting apply throttle few times with car
of the ground, to allow the engine to adapt to the new setting.
- Run the car again and check carefully the result.
- Watch closely for the smoke coming from the pipe.
o Small amounts of smoke, regular engine sound and fast
reaction on throttle > setting is ne, no adjustment needed.
o A lot of smoke and ‘4-stroking’ sound > mixture is too rich,
turn in (clockwise) the low speed needle with 1/16 turn.
o Engine stops, very little smoke, rpm/revs go up and down
> mixture is too lean, turn out (anti clockwise) low speed
needle with 1/16 turn per time and try again.
After Running the engine
- Remove fuel from fueltank
- Restart the engine to burn any fuel still left in the engine.
- Remove the airlter to clean/wash out and re-oil or replace
the foam fully.
- Insert a few cc of normal engine oil or after run oil in
the carburetor and pull the pullstarter 5 times, so the oil can
move inside the engine and lubricate and protect the engine
against corrossion; apply a rubber cover over the carburetor
intake (in case you do not remount the airlter yet) to prevent
any debris to enter the carburetor during car cleaning
or maintenance.
- Wipe of oil and dirt carefully
- Disconnect the receiver battery / switch off.
Engine maintenance
Its best to leave the maintenance of the engine to a service
center/rc dealer or experienced user if you lack experience by
yourself. You can learn by following the guidelines of the expert
user, or check out the online video’s on rc car engine
maintenance.
Problem solving Issue and >Solution
Engine doesn’t start.
- Too much fuel in the engine. >Remove the glowplug, then pull
the pullstarter, so the fuel will be pushed out. Be carefull for
fuelspray and use protective gloves and eye protection.
- No fuel in the engine. >Pull the throttle 5 times quicly and start
again. >Check if the pipe-outlet is not hot anymore, then apply
your nger to close the outlet pipe and pull the pullstart
5 times, check if fuel moves in through the tubing to
the engine.
o Check the silicone tubing and connections to the carburetor,
tank and pipe.
- Carburetor is not open for more than 0.3mm. >Re-adjust
the idle screw to allow 0.3mm or more opening = turn in.
- Glowplug does not glow red when applying the glowbooster.
Try another plug.
- Check if the glowbooster battery is charged.
Replace or recharge as needed.
Low outside temperature
Warm up the engine.
- by leaving the car in a warm room for an hour.
- by using a hairdrier.
Engine is overheating
Wait until engine cooled down, turn-out the high speed
needle with 1/8 turn and retry. The carburetor is blocked
or dirty > Clean with cleaner spray. Dis-assemble and clean
overall.
Air lter is blocked. Remove airlter and check for dirt;
clean or replace foam element as needed, and make sure to oil
before use.
Engine adjustment is not correct.
>Go back to the standard settings section and re-read
the engine tuning section as above.
For more information on engines and maintenance look
in the Serpent website section downloads and tech-tips.
www.serpent.com
Starting the engine
Notes before to start:
- Before you start the engine, rst switch on the receiver and then the radio and perform all checks as above.
- When pulling the pullstarter, make sure not to pull out more than 20cm. If you pull out more the device inside may damage
and the rope will not return into the case.
- When the engine is new it need a session of run-in, before the engine can be run at high speeds, follow the instructions as per below.
- If the engine does not start after 10 pulls, then stop and follow procedure as per below with title: Engine does not start.