Since having the wee dirt bike, both Kate and I have gone out on occasion and tootled around a field near Brandon. She got the hang of it pretty quick, the docile nature of 11 hp not catching her out in the least. It became so much fun that we talked about getting a second bike, so we could go riding together (at least in the summer). I thought this would be more of a long-term plan, as a second dirt bike of similar quality and reliability would be pushing $1500, at the least. In January, Wilson sent me an email saying that a guy in Killarney had a 2004 TTR in his shop. The big-end bearing had failed (a somewhat common occurence when these bikes are abused -- held at WFO throttle for a long time), and the shop owner just wanted to be rid of it. I called, asked a price, and headed down there to look at it. It turned out the cylinder was also pooched, as the skirt had a crack in it. The big end was seized, but there were no leaks coming from the case, so I hoped that the innards of the engine were still serviceable, even if the crank wasn't. I paid the man in cash (rediculously cheap, for what I was getting), loaded it on the trailer and headed home. Aside from the engine and a bent set of handlebars, the bike was perfect, if not clean. All the main parts were there, and for the price I paid, I would be able to build a slightly hot-rodded TTR for less than I paid for the stock 2003 we also had.
I set about taking the engine apart and out of the frame. Everything came off fine, except for the flywheel -- notoriously hard to remove. Since the crank was pooched anyway, I wasn't too concerned about it, but I ended up dropping it off at the Yamaha dealer, with instructions to remove the flywheel and split the cases. The plan is as follows:
- install new OEM crank, bearings, and timing chain
- purchased used OEM cylinder and a HC 125 or 130cc kit, OR complete BBR 150 kit
- get flywheel machined and lightened
- purchase oil seal kit
- aftermarket exhaust system
I need to be careful, as one could spend thousands souping these bikes up to a staggering 17hp! Surprisingly, the risk of buying a used OEM cylinder, getting it bored, and then buying a 125 or 130 kit would be the same cost as a complete 150cc kit, so I think I might go that route. The carb would likely benefit from some richer jetting... my goal, of course, is to make something that would give 200s, 225s, or even 250s a run for their money on the ice...
