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Super BN
Troubleshooting Guide
Problem
Possible Causes
Correction
Hard Starting
Incorrect use of primer
Review primer operation
Fuel lines improperly connected
Reconnect in correct sequence
Intake air leak
Check manifold connections
Ignition problem
*Repair or replace as necessary
Low cylinder compression
*Repair or replace as necessary
Idle speed set too low
Adjust idle speed according to
speciications in owners manual
Clogged idle circuit
Remove carb and chemically clean
Improper adjustment of low speed
adjuster
Adjust low speed adjuster for a
smooth idle
Slow return to idle
Idle speed set too high
Adjust idle speed according to
speciication in owners manual
Throttle linkage sticking
Clean and inspect linkage, lubricate,
repair or replace as necessary
Throttle cable sticking
Correct routing or replace as
necessary
Engine idles but won’t rev up
Pop-off pressure too high or low
speed jet too small
Adjust pop-off or low speed jet per manual
Engine “loads up” during extended
idling, i.e., in 5 mph zone
Leaking anti-siphon valve
Replace Valve
Leaking needle valve
Clean or replace needle valve
pop-off pressure to low
Increase pop-off pressure - See “Low Speed
Adjuster” section on Super BN tuning page
Low speed jet too large
Replace low speed jet with smaller size jet
Engine surges when cruising at con-
stant throttle setting
Incorrect air/fuel mixture
Mid range - change low speed jet
High speed - readjust high speed
adjuster
Engine does not develop full power or
misses during acceleration
Clogged air cleaner/lame arrestor
Clean as necessary
Throttle not synchronized (Dual carb
applications)
Re-synchronize carbs
Clogged fuel ilter or water separator
*Clean as necessary
Components loose in carb, i.e., jets
Tighten as necessary
Ignition problem
*Repair or replace as necessary
Low cylinder compression
*Repair or replace as necessary
Carburetor is too lean at full throttle
and turning out high speed adjuster
has no effect
Needle valve size is too small for
engine needs
Replace jet with larger size
High speed jet too small
Replace jet with larger size
Carburetor too large for engine
Use more restrictive lame arrestor for
smaller carb
*Refer to Shop Manual for your craft
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