Hello guys - There is a lot of post out there giving the MP3 500ís engine a bad wrap on dependability. On the other hand, there is numerious posts of owners having great results and thousands of miles of trouble-free use.
I personally feel the biggest problem with the MP3 engine is; its like being stuck in 6th gear all the time - by that I mean; the engine is always lugging and torquing which is hard on any engine, much less a single cylinder thumper. The MP3 is essentially in jail with its CTV clutch that never lets the engine catch up or operate in its power band like a standard shift transmission does. As we all know, on a standard shift, as an engine winds up in speed as it tops each gear, its that kinetic energy of that rpm that launches enough power to deal with the next higher shift ratio. Regretfully, the MP3ís belt tranny never offers the engine this opportunity to peak in rpm, its captured and canít get away. The MP3 engine is bogged and constantly under load, it needs to breath. Running at around 4000 rpm (most of the time) while accelerating, riding two-up, or climbing an incline, this forces this engine to work twice as hard as a manual shift bike. As I mentioned, I really feel this is why these engines are having problems.
The ultimate MP3 would have a transmission like Hondaís DCT Dual Clutch transmission where there is no power loss and the transmission shifts by itself, or the rider can shift it. Iíve been running Hondaís DCT bikes for years, on their NC7,CTX and still own my NM4. In brief, the way it works is there is a clutch for 1st- 3rd & 5th gear, then another clutch for 2nd,4th & 6th gear. When it or you shift, all it does is disengage on clutch and engage the other instantly. This is the same transmission principle as million dollar race cars use, because unlike a hydraulic tranny there is no loss and it shifts faster than any transmission made. Anyhow the future of scooters is already out and its called the Honda X-ADV which uses this same exact DCT transmission which is pushed by a 54 hp 745cc engine. This is ultimate scooter / dual sport or what ever you want to do bike. There is tonís of videos on this bike hereís a few. Iím waiting for this bike to be released to the US!
Anyhow, getting back to the MP3, it appears the only fix is to drop the gearing and up the rpm. So Iím putting this post out there and hoping some of the MP3 experts on this great forum could help me make the right decision when I change my clutch performance.
I went out today and recorded some GPS speeds verses engine rpm in hopes of a few guys sharing their data after they changed the clutch. Below I listed 3 different speeds. Mine is a bone stock 2018 500. It was difficult getting these speeds since the clutch takes time to settle at one rpm.
30 mph = 3600 rpm
45 mph = 4300 rpm
50 mph = 4600 rpm
55 mph = 48-4900 rpm
If anyone has changed their ratio and could take the time to record some figures it would be great. For myself, I donít want the engine screaming at 65 mph, so Iím going to go with a mild change on my first try. Iím thinking if I could get another 500 rpm, it would make a big difference on both off the line and improved climbing.
Thanks - Mike