My grandfather used to own a Rajdoot Ranger 175 and he would use it to commute to Mumbai for his work and ride down to Pune for the weekends. In 1976, one fine Monday, when he saddled up to head for Mumbai he could not get the motorcycle started. Befuddled, he checked every basic connection, but to no avail. Unbeknownst to him, my father and his brothers had opened up the motorcycle over the weekend and put it back together, a few parts still lying outside after their feat. I am sure they got a sound hearing to put it mildly. I know that because I went through the same ordeal as I had opened up my father’s Hero Honda Karizma. While I did not go to the extent of opening up the engine, I had stripped it down to just the frame and motor, in my backyard. I did put it back together confidently and then rode the bike gingerly to a friend’s garage just to make sure I had not mucked up. So I guess the engineering zeal of opening up motorcycles is in my genes and I could not let anybody else in the office take up the opportunity to head down to Gurgaon where Harley-Davidson India were going to teach us to service rebuild a big-bore V-twin engine from their portfolio.
Our university was located in Capital Harley-Davidson, Gurgaon with classes taking place on the first floor where we were made to go through the basics of the engine architecture and the way Harley has gone about designing the motor that we would be working on. Oh, did I not mention which one. It is their crown jewel and the one which I fell in love with completely – the Milwaukee Eight 107. Harley uses this very facility to train their technicians with several tutoring sessions held over the year with varied courses ranging from basic servicing to major rebuilding of sub-assemblies, just like the one we were going to undertake. Our headmaster for the session was John McEnaney. John has been the head in technical training in Asia Emerging Markets and is based out of Singapore. So we journos were in good hands when it came to teaching as well as keeping us in order.
There are a couple of iterations of the Milwaukee Eight 107 motor. You have got your dual counterbalanced version which powers the Softails, which are air-cooled in nature. Then you have two versions of the single counterbalanced motor – the first one featuring precision oil cooling method and the other being precision liquid cooled. Precision cooling enables heat dissipation via identifying pressure points, allowing the heat to remain where it is more beneficial to the engine – in the combustion chamber. Hence you have fins as well as a heart-shaped passage, grooved into the Lower Head Cover.
Also, we had to revisit our four strokes – Intake, Compression, Power and Exhaust (or as I was taught correctly Suck, Squeeze, Bang and Blow) and the position of the piston at the end of each stroke as it would come in handy when dissembling and re-assembling the motor later on. Thankfully, we did not have to contend with the transmission and hence was already off the engine.
In the Laboratory
Before we could actually start getting our hands dirty and spend the good part of the day opening up the 107, we were made to kit up by wearing cumbersome safety boots and goggles (a hindrance for people who wear spectacles, like me). John told us as long we followed instructions to a T, our process would go along smoothly. Sitting bolted on to jigs on our workbenches were eight Milwaukee Eight 107 motors, three individuals working on each one of them. Thankfully, we did not have to contend with the transmission which was already off the engine.
The process began with a simple task of removing the intake manifold along with the small peripheral sensors and the oil filter. Upon starting itself we found our first hurdle. The bolts that Harley uses are of imperial sizing and we tried opening them up with metric tools. John commented, “Over the next two days and furthermore, you guys should understand this – Imperial good. Metric bad.” Alrighty then. Imperial tools it is then for the next two days.
Lead on, Lord Commander
As John commanded, the parts started coming off and my smile grew wider and wider. The cams, oil pump, push-rods and activators came off early. Next to go, were the big essentials such as the cylinder heads, pistons. We finally split open the crankcase, revealing the massive flywheel and the single counter-balancer. We were made to inspect them and arrange them in an orderly fashion as the following day we would be putting them back together. The best thing about this entire exercise was that the assembly process went ultra-smooth. We torqued the bolts as the manual specified and as it deemed enough. Thus bolts on, for example the injectors required less torque than cylinder heads, for obvious reasons.
Harley has designed the engine quite beautifully as it is quite simplistic in nature. There are grooves and markers that one needs to be certain of while assembling the engine back together. Like for instance, I was quite curious regarding the timing of the camshaft. We were told to just align the bearings and insert the single camshaft into the designated space. Little did I know that the groove on the sprocket affixed on the shaft would get things moving in order.
I would be wrong if I said that I got more joy in building the engine back than opening it up but nevertheless you get this overwhelming sense of self belief and immense confidence after checking out that the task has been accomplished successfully. No causalities. There were no parts left behind or out on the workbench. It was great to have a service manual at hand to keep an account and follow the procedure as it really simplified the task. What next you ask? I have just acquired the service manual for my current ride and will be opening her up soon. Wish me luck!