“You know nothing, Jon Snow.”
I am actually a Stannis Baratheon fan, but this one dialogue from the Game of Thrones fits this Yamaha R15 V3 build pretty well.
To get a bit more power from this 155cc bike, I had to go beyond the wall (outside India), completely clueless about what to do or where to even begin. Okay, enough of the silly GoT references.
With performance build options extremely limited in India, I started exploring Thailand and Indonesia. Parts arranged (detailed in the last video), my good friends at Speedmonks Performance Centre in Gurgaon agreed to build the bike for me.
First, the easy part. Fitting the Kawahara racing coil was a piece of cake as well as the aRacer spark plug and SKA air filter. The new 49 tooth rear sprocket (stock is 48), and the new Asahi golden chain was simple enough too.
And then we started opening up the engine (Just the top cover from where we can access the camshaft and valve springs). The BRT Camshaft that I bought from Indonesia did not come with a bearing - you apparently have to buy it separately - and so we had to press fit a bearing onto the new cam.
Thankfully, Atul (Technical Head at Speedmonks) has extensively worked on the R15 V1 and knows that machine inside out. He had a stock of the R15 bearings lying around and we made use of one.
Some jugaad and a few hours later, we had a camshaft that we could finally use. The new cam has slightly aggressive lobes that will keep the valves open just a fraction longer, resulting in more air and fuel entering the engine.
We decided against opening the head to replace the new, stiffer valve springs as we did not have a new gasket (couldn’t find it in stock at local Yamaha dealers).
Also, to maximise the gains, since we are now thinking of getting a big bore kit (not yet sure of whether to get 62, 65 or 66 mm), it makes sense to open up the engine only once.
So, the valve springs are on hold till this project goes into Phase II.
Time to bring out the big guns then. The Juken ECU. While installing the ECU was a straight-forward affair, connecting it to its supplied software was not.
After struggling with it for another hour, and unable to find the required drivers (we were using a Windows 10 laptop), we switched to a Windows 7 desktop and it finally connected.
The software looked simple enough, yet is completely new to us.
There are a couple of maps on the ECU, but for now, we are sticking to the one that came pre-loaded on it. It is calibrated to the BRT camshaft, so that is a relief. After testing the bike for a 100-odd kilometres, we will start playing around with different maps, and try and come up with one that I like.
The bike will be tuned on the dyno, and the results will be shared here for all to see.
But how does it ride currently?
Not that different, to be honest.
The low-end has dropped and I wasn’t able to take it past 6,000 RPM since I only rode is some 200 metres in the bylanes.
25 BHP bike? No, most certainly not, right now.
But with the big bore kit, I am certain we will get there, and no, I don’t mean at the crank. I am talking rear wheel figures.
Till then, this bike is a work in progress, and I am learning with each step.
Stannis Baratheon lost his head chasing the Iron Throne (He was the rightful heir, mind you), I just hope I keep mine (No blown pistons, please).
I am going to drop a teaser for the next phase of the build: Upside Down Front Forks from the International model of the R15 V3. Details on my Instagram page: https://www.instagram.com/abhinavbhatt19/
Speedmonks, who are working on my bike, can be contacted here: https://www.facebook.com/SpeedMonks.in/
The BRT Juken ECU, BRT Camshaft, Kawahara Racing Coil, ECU tuning cable were bought from IWS Motorsport in Indonesia for about 280 US dollars. Shipping was another 58 US dollars and customs was 42 per cent of 280 dollars. Total cost in INR: 28,000. You can contact IWS Motorsport on their Instagram page: https://www.instagram.com/iwsmotorsport/
The detailed break up of all parts that I got from Thailand and Indonesia is here: https://www.youtube.com/watch?v=ytXXh3lWqwY
If you have any doubts, any feedback to share, drop me a comment below and hopefully we can have a discussion over it.
As always, I thank you from the bottom of my heart for giving me your valuable time.
Have a nice day.