Yamaha RST90G Owner's Manual page 110

Troubleshooting
3. Compression
 Insufficient
• Loose cylinder head nuts:
Tighten nuts properly.
↓
• Worn or damaged gasket:
Replace gasket.
↓
• Worn or damaged piston and cylin-
der:
Ask a Yamaha dealer to check.
Discharged battery
If the battery is discharged, the engine can be
started using a fully-charged 12-volt battery
and jumper cables. Two connecting leads
have been provided for jump-starting the
snowmobile. Due to the rubber engine
mounting, the snowmobile frame is not a suit-
able grounding point for jump-starting the en-
gine.
EWS00571
WARNING
 Connect the jumper cables only to the
connecting lead terminals. Do not con-
nect them to the frame or any wire or
other lead.
 When connecting the jumper cables, do
not contact the jumper cables or con-
necting lead terminals to each other or
to the frame or any metal part of the
snowmobile. This can cause electrical
system damage or A FIRE HAZARD.
 Be sure to pull the lead covers back over
the terminals completely. If the termi-
nals are exposed, they could come into
contact with the frame or a metal part of
the snowmobile and this can cause
electrical system damage or A FIRE
HAZARD.
104
ECS00651
NOTICE
Use the connecting leads to jump-start
the snowmobile only. Do not use the con-
necting leads for any other purpose.
To start the engine using the booster battery
1. Apply the parking brake and turn the key
to the off position.
2. Remove the shroud and the right side
cover [RST90TF /
RST90TFY (see page 60 for the proce-
dures)], or open the shroud [RST90 (see
page 62 for the procedures)].
3. Remove the red (+) connecting lead from
the lead holder and move it away from
the black (–) connecting lead. NOTICE:
Be sure to connect the red (+) jumper
cable to the red (+) connecting lead
and the black (–) jumper cable to the
black (–) connecting lead. Do not re-
verse the connections.
RST90TFL /
[ECS00662]