Adjusting Carburetor; General Adjusting Rules - Yamabiko ECHO PB-2520 Service Manual

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6-6 Adjusting carburetor

6-6-1 General adjusting rules

A. Before adjustment, check the following items.
1. The correct spark plug must be clean and properly gapped.
2. The air lter element must be clean and properly installed.
3. The muf er exhaust port must be clear of carbon.
4. The fuel lines, tank vent and fuel lter are in good condition and clear of debris.
5. The fuel is fresh ( > 89 octane :
M345-FD" 2-stroke oil.
6. All blower pipes are installed for proper engine loading.
B. Preliminary adjustment : Adjustment by Throttle adjust screw of carburetor.
Start and run engine for 10 seconds at idling and then run for 180 seconds at WOT. Verify idle engine
speed ranges from 2,800 to 3,200 RPM, and WOT engine speed is over 7,150 RPM. If idle engine speed
is out of range, adjust throttle adjust screw to 2,800 - 3,200 RPM. Make sure WOT engine speed is over
7,150 RPM again. If engine does not run correctly after this adjustment, proceed to the next step 6-6-2.
6-6-2 Initial setting Throttle adjust screw, L mixture needle and H mixture needle
D
1)
RON+MON
2
A
B
C
2) 3)
FUEL SYSTEM
) and properly mixed at 50 : 1 with "ISO L-EGD" or "JASO
Tools Required: P/N G310-000050 Tachometer
PET-304, P/N Y089-000094 Carburetor adjustment
tool KIT (Driver(2.5mm)), P/N 91077 Limiter cap
remover KIT(Limiter plug tool)
Parts Required: (2) limiter plugs P/N P005-001270.
1. Remove plugs from L mixture needle hole (A)
and H mixture needle hole (B) using limiter plug
tool (C) as follows.
1) Put limiter plug tool (C) on limiter plug in mixture
needle hole.
2) Screw limiter plug tool counterclockwise (CCW)
2 turns into limiter plug pushing the tool against the
plug to engage tool threads.
3) Pull out limiter plug tool, with the limiter plug,
from mixture needle hole.
4) Repeat plug removal procedure for the other
mixture needle.
NOTE: If the plug is damaged and left in the hole,
use a needle or pin-shaped tool to remove de-
formed plug pieces.
PB-2520
EB252