I recently low-sided the bike on a particularly slippery corner on my way to work. Apart from some bumps and bruises I was fine, but the bike didn’t like being dropped very much. I ended up having to replace the steering stem bearings to get the handling back to normal. Aside from that there was the usual cosmetic damage. I needed a new windscreen, and the exhaust shroud was all messed up.
Instead of replacing that annoying plastic exhaust shroud, I decided to try a cheap aftermarket exhaust on the bike. I ended up ordering the below from Aliexpress for around NZD $60.00.
https://www.aliexpress.com/item/1005006863899177.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.1.51b4CKPNCKPN3W&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=18d1b2f5-0d1e-48ea-8d80-d185a3dcce03&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:18d1b2f5-0d1e-48ea-8d80-d185a3dcce03,tpp_buckets:668%232846%238108%231977&pdp_npi=4%40dis%21NZD%21129.80%2164.90%21%21%21559.50%21279.75%21%40210318ec17270487012103333e5a8c%2112000041506297833%21rec%21NZ%214271177227%21X&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_from%3AIt was extremely easy to fit and I was happy with the look of it. It’s also significantly lighter than the stock exhaust. At a guess the aftermarket one weighs about 0.5kg while the stock exhaust must weigh close to 3.5kg. Unfortunately, it quickly became apparent that the new aftermarket exhaust wasn’t going to be usable in its initial form. It was simply way too loud for a scooter. It comes with a “db killer” installed in the rear, but even with that in the noise is obnoxious. I didn’t dare run the thing without the db killer installed. The second issue was that with a much more free flowing exhaust system, the bike was now running on the wrong side of lean. This was most noticeable diving in traffic at 55-60kph when you are barely on the gas, in 1%-5% throttle area. The bike was a little boggoy and simply not happy there. It was fine when giving it more throttle, but as I spend a lot of my time commuting in traffic only barely on the throttle, it wasn’t going to work for me.
So I did some research and came up with a couple of additions to hopefully help the noise and the running lean issue. I ordered a couple of extra silencers to try out, both of which slot into the front of the exhaust. These made a massive difference to the sound, dramatically reducing it to where I was happy riding it in public again. They also helped create a bit more back pressure in the exhaust and the “low throttle” bogging was a lot better. But the other thing I purchased was this little unit from Malossi.
https://www.malossistore.com/en/nz/tc-unit-o2-controller-lambda-emulator-kawasaki-j-300-ie-4t-lc-euro-3-ws60-5516341b-kaj300-M-PFrom what I could find online, it seems this ticks the ECU into dumping more fuel in the system by adjusting the values the O2 sensor sends back the ECU. It took 6 weeks to arrive, but I finally received it last week and went about installing it. My first impressions are positive. It does feel like the bike has a bit more power. I didn’t set out trying to improve performance, I just wanted a better looking and sounding exhaust. But it’s a definite positive to have the bike feel like it’s got a bit more pull. The bike is now smooth throughout the rev range and when I do open it up it’s a little more fun than it was before.
There are a couple of other things I’ve noticed since installing the Lambda Emulator. Firstly, the bike takes a bit longer to get up to operating temperature now. I’ve done 80,000 km on this machine commuting to and from work. I know exactly the point in the early part of my journey each morning that the second bar on the temperature gauge lights up. Initially I thought I might have a temperature sensor problem as the bike hadn’t warmed up in the normal time, but about half a kilometer further down the road from normal the bike eventually reached normal operating temperature. It’s consistently now taking this longer time to warm up, and this is even as the outside temp is warmer now than in mid winter. So I can only guess that running richer is making the bike run a bit cooler?
Secondly, there seems to be less “engine braking” resistance when off the gas and “free wheeling” so to speak. I really wasn’t expecting that, but it’s been noticeable from the first ride with the Lambda Emulator. My bike did seem to have a fair amount of “engine braking” before. I’ve ridden identical machines which definitely coasted along off the gas much easier than mine, but I’ve now seen an improvement in that area which is a nice bonus.
Overall, I’m pretty happy with the current set up. I’m enjoying the daily commute on the bike as much as I ever have, and that alone is worth the cost. This bike has been my daily driver for the past 5 years and hopefully I’ll get a couple more out of it yet.
