Originally Posted by btsom

Several different problems blended together here, first the OP. If your starter is having trouble getting through the first compression stoke but NOT accompanied with any bang or grinding noise, it is a weak battery or bad connections in the starting circuit. You need to check both ends of both battery cables for clean and tight connections. If they are good, put a digital volt meter on the battery and watch it as you hit the starter. If the voltage drops below 9.6 the battery is "tired" (needs to be replaced) or undercharged. If you have about 14.5 volts going to the battery while the engine is at 2000 rpm or above, the charging system is good and it is pretty solid that the battery is on the way out., UNLESS most of your rides are of short duration and there isn't enough time to fully recharge during each trip.

Now for the bang and grind. From 07 through 10 with the 96 and 103 engines, the compensator was a design left over from the smaller displacements and in most cases just wasn't up to the job. When the starter engaged, the weak compensator would run right to its limit and slam against its stop placing a heavy shock load on the crankshaft and back through the primary chain into the starter drive. That bang was the comp slamming its limit. The starter drive includes a sprag over run clutch. The design consists of some short, fat needle bearings sitting on ramps in the drive hub. When the hub is driven (starter engaged) the needle bearings run up the ramps until they are jammed between the ramps and the clutch housing. It is a simple design that works pretty well until it gets "beaten to death" by the repeated shock caused by the weak compensator. When it slips, it makes that terrible grinding sound as the needles rapidly try over and over to get a grip on the housing. If the starter drive is replaced without replacing the compensator, the beating to death process starts all over again. If the compensator only is replaced, you still have a well worn starter clutch which will fail fairly soon. Replacing both is needed for a long term fix.

Failure to energetically crank through the first compression stroke is an electrical problem, while the bang and grind are mechanical problems. The first is most commonly fixed with a new battery, while the second requires some expensive replacement parts.

Originally Posted by btsom

Several different problems blended together here, first the OP. If your starter is having trouble getting through the first compression stoke but NOT accompanied with any bang or grinding noise, it is a weak battery or bad connections in the starting circuit. You need to check both ends of both battery cables for clean and tight connections. If they are good, put a digital volt meter on the battery and watch it as you hit the starter. If the voltage drops below 9.6 the battery is "tired" (needs to be replaced) or undercharged. If you have about 14.5 volts going to the battery while the engine is at 2000 rpm or above, the charging system is good and it is pretty solid that the battery is on the way out., UNLESS most of your rides are of short duration and there isn't enough time to fully recharge during each trip.
Now for the bang and grind. From 07 through 10 with the 96 and 103 engines, the compensator was a design left over from the smaller displacements and in most cases just wasn't up to the job. When the starter engaged, the weak compensator would run right to its limit and slam against its stop placing a heavy shock load on the crankshaft and back through the primary chain into the starter drive. That bang was the comp slamming its limit. The starter drive includes a sprag over run clutch. The design consists of some short, fat needle bearings sitting on ramps in the drive hub. When the hub is driven (starter engaged) the needle bearings run up the ramps until they are jammed between the ramps and the clutch housing. It is a simple design that works pretty well until it gets "beaten to death" by the repeated shock caused by the weak compensator. When it slips, it makes that terrible grinding sound as the needles rapidly try over and over to get a grip on the housing. If the starter drive is replaced without replacing the compensator, the beating to death process starts all over again. If the compensator only is replaced, you still have a well worn starter clutch which will fail fairly soon. Replacing both is needed for a long term fix.

Failure to energetically crank through the first compression stroke is an electrical problem, while the bang and grind are mechanical problems. The first is most commonly fixed with a new battery, while the second requires some expensive replacement parts.

Originally Posted by kneesinthebreeze24

I know this is an old thread, but I post up my results anyway for future reference.
BTW, my bike symptoms were the same as OP. Hard time starting ONLY after the bike was hot. Ends up , bad compensator. Replacing with the screaming eagle comp.