Found myself reeled into this discussion on the other forum, figured I'd bring it over here as well. A big part of what makes the modern Indian Scout an exciting motorcycle is the unusual performance characteristics of its engine when compared to most other v-twin cruisers. Being a liquid cooled, dual overhead cam, short stroke engine means it was designed to rev high and maintain consistent torque across a wide rev range. This is a departure from traditional American cruiser design. Most Harley-Davidsons and many of the Japanese competitor models that have appeared over the years were air cooled, overhead valve, long stroke, push-rod engines designed to make peak torque at a relaxed cruising RPM. For example, the Harley-Davidson Fat Boy makes its peak torque at 3000 RPM. The Indian Scouts make their peak torque between 5500 and 6000 RPM, twice as high in the rev range, and are still over 2000 RPM away from their upper redline of 8300 RPM. For most cruiser riders, that is a very different power band than what they are used to, and it's difficult to adjust when transitioning from a traditional cruiser to a sportier creature like the Scout. Since a lot of Scout owners did transition from traditional overhead valve cruisers, a lot of them are riding the Scout the same way they rode their previous bikes. While this is not immediately problematic, as the Scout's power band does begin around 2500 RPM, and it will ride smoothly at that RPM, it does mean that the Scout is at a higher risk of being "lugged" than other cruisers, which may lead to premature engine failure for some riders. This post is an effort to explain why it is beneficial and safe to ride the Scout higher in the rev range than most typical v-twin cruiser style motorcycles. The primary reason that we ought to avoid cruising at an RPM of 2500 is that it is right on the edge of "lugging" the engine. If you're cruising in the 2500 RPM to 3000 RPM range all it takes to accidentally fall below 2500 RPM is letting off the throttle for a second or two. Once the engine RPM falls below 2500 it is no longer running within its power band and it has to work harder to carry its load. It probably won't stall, but it will require more throttle than usual to climb back into the power band. This isn't an immediate problem, but over the life of the bike, if this is something that happens every time it is ridden, it will shorten the life of the engine. The easiest way to imagine what "lugging the engine" feels like is to compare it to riding a geared bicycle. If you're pedaling along at a low speed with the bike in a high gear and you try to accelerate quickly it's going to require much more leg strength to get the bike moving than it would if you were in a lower gear. You'll sweat, your legs will get sore, and you'll become exhausted very quickly. The same thing is happening to an engine when it tries to take off from below its power band. More specifically: - Combustion chamber temperatures rise (risk of overheating parts) - Timing accuracy decreases causing uneven combustion (risk of engine knocking/pinging/"piston slap") - Piston slap causes cylinder wall and piston ring damage - Piston slap ripples excess forces throughout the bottom end and power train - Cylinder wall and piston ring damage causes oil burning - Oil burning causes loss of lubrication and carbon buildup - Carbon buildup further decreases engine efficiency and increases heat causing all of the above Cruising higher up in the rev range allows you more leniency to let off on the throttle without accidentally falling below the power band and lugging the engine when throttle is re-applied. The dyno chart below from Fuel Moto shows the torque curve of the stock Scout 69 engine. You can clearly see that the torque curve dives downward below 2500 RPM. The dyno runs will never measure as low as 2000 RPM because it is inefficient and harmful to run the engine that low for the reasons stated above, the same applies in the opposite direction when revving the engine above 8000 RPM (which is why the ECU is programmed with a rev limiter, preventing that from ever happening). A comfortable cruising RPM for the Scout engine is a number of your choice between the green lines below. The lower that number, the higher the risk of falling below the power band during deceleration. The higher that number, the higher the amount of vibration in the foot pegs and eventually the handlebars, but the engine will not care. It's up to the rider to choose a cruising RPM that balances comfort, risk of lugging, and accessible power. For some that will be 3000 - 4000 RPM, for some it will be 4000 to 5000 RPM. The engine will be happy and safe at any of those numbers, but it will not be happy below 2500 RPM. The curve is almost identical for the Scout 60 up until a little over 6000 RPM where the factory ECU configuration causes it to dive. With a PVCX Scout 60 tune the higher end of the torque curve is restored and very closely matches the curve above (in shape, not peak torque). I apologize for the wall of text but it has to be shared. I fear that there are a lot of Scout owners out there used to low revving air cooled pushrod cruiser engines that simply don't know how different the Scout engine is. Knowing the difference and why it must be ridden differently to maximize the life of the engine will cause the owners less grief in the long run and will improve the quality of the second hand Scouts out there in the used market.