Motorcycle Repair: 99 low mile shadow wont turn over, jumper box, starter solenoid

Question
Hi my name is joey and here is some basic information. I am 25 years old and im a ford automotive tech and have been a mechanic for about 8yrs so i do have basic knowledge on mechanical and electrical items and how they function. I recently purchaced a 99 shadow 750 ace w/4k miles bought it on Friday bike sat so I changed oil/filter (oil smelled like fuel) with honda approved products flushed cooling system checked all fluids and rode about a total of 65 miles performed well all weekend did hear a silght clicking/tapping?  sound coming from motor sound followed/matched motors rpm upon acceleration and stopped when clutch was engaged  and load was taken off motor .engine also bogged and hesitated til about 800-1000rpm then motor performed good once out of the lower rpm range owner hollowed out factory ehsaust  he claims that the carbs were adjusted???? went to start on monday and when i pressed the start switch it started to crank normally for about 2 sec did not fire then a pop/clunk mechanical noise came from left side of motor "trans drive side" went to start again and had nothing but a clicking noise coming from starter or solenoid? everything has power and headlight does dim indicating that there is a electrical load tried tapping on starter solenoid still nothing tried directly jumping starter and performed all test will a jumper box just makes a sound like it wants to engage but does not do anything what do you think?"

Answer
Hi Joey,

The clunking sounds like a problem inside the engine case
where the starter drive assembly is.

However,
If it is just electrical then it might just
be a sticky starter button or starter
solenoid relay.

It might be possible that the alternator rotor
has come loose or some starter drive parts
are hung up somehow.

I would remove the left footpeg, shifter
lever etc and carefully remove the left
engine cover to see if something is wrong.
The alternator stator is also under
that side. Pull the cover off straight
and carefully to avoid stator coil damage.

The starter drive assembly is like a one-way
clutch bearing. It grabs in one direction
only. It is under the flywheel or rotor.
The rotor requires a puller and is left
hand threads unless you find it has come loose already.

If the engine will not turn over then something
could be jamming the starter drive or
alternator rotor.

If all looks okay under there then
gently try turning the engine by hand
to see if it can turn.

If it is just a starter problem then
you can check the battery condition,
starter and cables first, then
the starter button, relay solenoid
and the starter drive assembly last.

If you need more info let me know
with a follow up.

Wayne S.
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