Engine Lacks Power - Honda 1998 VT750C Service Manual

TROUBLESHOOTING
ENGINE LACKS POWER
Possible cause
1. Raise wheel off the ground and spin b y - - - Wheels do not spin
- - - - - I .....
Brake dragging
hand f r e e l y · Worn or damaged wheel bearing
I
Wheel spins freely
+
2. Check tire pressure - - - - - - - - - - - Pressure low
- - - - - - 1 ......
Faulty tire valve
I •
Punctured tire
Pressure normal
+
3. Accelerate rapidly from low to second - - - - Engine speed doesn't - - -
I
change accordingly
Engine speed reduced when clutch is when clutch is released
relased
+
• Clutch slipping
• Worn clutch discs/plates
• Warped clutch discs/plates
• Weak clutch spring
• Additive in engine oil
4. Accelerate lightly - - - - - - - - - - - - Engine speed does
- - - - - i .....
SE valve ON position
I
not increase • Clogged air cleaner
Engine speed increases • Restricated fuel flow
I .
Clogged muffler
• • Pinched fuel tank breather
5. Check ignition timing - - - - - - - - - - Incorrect
- - - - - - - - - 1 .....
Faulty ignition control module
I .
Faulty ignition pulse generator
Correct
+
6. Test cylinder compression - - - - - - - - Incorrect
- - - - - - - - - 1 .....
Valve stuck open
I •
Worn cylinder and piston rings
Normal • Leaking head gasket
+ .
Improper valve timing
7. Check carburetor for clogging - - - - - - - Clogged - - - - - - - . . . . . . . • Carburetor not serviced
I
frequently enough
Not clogged
+
8. Remove spark plugs - - - - - - - - - - Fouled or
---------1....... .
Plugs not serviced frequently
I
discolored enough
Not fouled or discolored • Spark plugs are the incorrect heat
+
range
9. Check oil level and condition - - - - - - - Incorrect
- - - - - - - - - i..
~
.
Oil level too high
I .
Oil level too low
Correct • Contaminated oil
+
10. Remove cylinder head cover and inspect - - - Valve train not
- - - - - - l ...
~
•
Clogged oil passage
lubrication lubricated properly • Clogged oil control orifice
I
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