Questionhi I was riding my bike this am and pushed it to 70 mph in 2nd gear now it has a kind of knock on the right hand side of the engine in the bottom of the crank case it only makes this noise at low rpm and idle. It also seems to have lost power unless you get the rpms up above 3000 rpm it I pulled the plugs they looked good no oil or fouling evident. any ideas? please help if you can
AnswerHi Jeffrey,
There is only the starter drive unit and clutch on the
right side for the most part.
Any other noises would have to be from
the engine main bearings.
The alternator flywheel is on the left side.
The clutch and right side drive gear and starter
drive unit could be checked by pulling the
right engine case off.
You could also check the oil drain plug for signs
of metal or metal filings.
If you see aluminum particles in the oil or
oil filter it may mean one of the engine
bearings is going bad.
A compression check will tell you if the compression
is reading okay on all cylinders.
These engines use bearing shells similar to automobile
main and rod bearings. They are sandwiched inside
the engine crankcases so the engine has to be split
to change them and check the crankshaft etc.
If nothing looks loose in the side cases
then it may need engine bearings which is
a big job unfortunately.
Sometimes a bearing shell can last awhile even
when loose if it is on the crankshaft mains.
Rod shells are likely to hammer out more quickly.
Check the clutch hub nut and front gear or
try to pinpoint the noise with a long screwdriver
or mechanics stethascope first just in case the
noise is travelling from another part of the engine.
Good luck!
Wayne S.
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