How does one train a Pixie to beat a Giant? The 250 project

In short, you don’t, but you can certainly train the pixie to run far far away, and go play in a different meadow. I have told myself I’m not allowed to get a different bike until I put 100,000 miles on the 250. My 250 is a pixy compared to some of the monstrosities out there. I was reminded of this when I helped a friend recently get her ZX-10R home. My, what a ride! So I asked myself a question: Why did I set such a silly goal for myself? Because I’m stupid and masochistic! Well, actually, it is to save money. I wanted more and more, faster and faster, and that doesn’t just cost you in out-the-door price, taxes, registration, insurance, tires and all that good stuff… It costs you in the courts as well. I also thought I’d become a better rider, and honestly, I have. But enough of that. What it comes right down to is that I’m getting very bored with my 250. I could go faster on it if it had a bit more power, but I’m literally riding it to the engine’s limit, as in red-line, in top gear. If I simply change the gear ratios, I will go nowhere very slowly. It needs more power. Period.

So, in order to achieve my goal of 100K  I have rationalized this pursuit of power! In optimizing the bike, I can learn much more about ICE (internal combustion engines), something I’ve been doing since the 7th grade, keep saving money, and hopefully, eventually complete my goal. Luckily, there aren’t a whole bunch of go-fast parts which I can just slap on the bike to make it go faster, so my wallet is reasonably safe. I’ve spend the past year and a half collecting various parts which I’d need to achieve an equally lofty goal to the 100K thing, and that is to coax 40hp out of the 250 using nothing but the stock parts. The more and more I do research, the more I realize this is an unrealistic goal. However, shouldn’t our goals be impossible? I mean, that implies that even when we fail, we still accomplish the improbable, the very-much-beyond-normal, the excellent… So, all of this hit me half-way through my 2-weeks of wrenching mayhem.

Here is my plan:

1.) Return to stock setup, have it dyno’d to get a base line HP.
2.) Install data logger to tune future mods with.
3.) Re-Install modified airbox, tune, run dyno
4.) Install modified exhaust, tune, run dyno
5.) Install flowed head, tune, run dyno.
6.) Experiment with cam-timing, run dyno.
7.) Experiment with ignition timing, run dyno.
Optional: Install 13:1 pistons, have it dyno tuned.

This should keep me busy and interested in the 250 for at least this summer, and shouldn’t cost a whole lot to do. Luckily I had stripped out the cam cap cover bolts on my head while adjusting the valves, which means I had to acquire a new head for me to use and feel comfortable riding the bike on a day-to-day basis. You might say I’m crazy, and that in fact stripping threads is always a tragedy, but I say that I learned from the situation, and that it has provided me with another opportunity! This means I have an extra head, which I could take my time porting and polishing once I get to step 5. All in all, this whole escapade should cost me no more than $1170. Wow, that’s a lot of money!

That’s a third the value of a motorcycle, and the down payment on a much bigger bike… But ah, wait. It should be obvious that I like to fondle things. $900 out of the $1170 is going towards highly sophisticated tools, measurement tools and contraptions which I will be using to gauge how successfully I can modify the newly acquired stock parts, and which will be used for many years to come, as I fondle other motorcycles (2 of which I already have, 1 in boxes – but that’s a different thread many moons from now). So, in reality, these modifications are only costing me $270, and don’t forget all the knowledge I acquire during this process… In the US, knowledge is expensive, so I’m very happy with this arrangement. Call me silly, call me daft, but nobody is talking me out of this one! If, at the end of all this, I still need more power, I have given myself the go-ahead to buy high-compression pistons ($400) to get to 40HP. I mean, the stock clutch will only take 40hp, and I think this bike would be killer fast with that much power. Anyways, enough with the musings, what have I done so far!

I have completed goal #1: Return her to stock and have a baseline dyno done. I have also put on the second, still stock head so I can fix the original stock head’s threads when I port/polish/flow it.

Cherry certainly looks naked and vulnerable on the operating table. I sweat buckets during this procedure.

So clean! You wouldn't say they've done 40K worth of work. Hooray for engine cleaner and a brass brush!

The valves on the left have not been cleaned. This is the new, stock head going on the bike.

The stock engine dyno graph. 24.86hp. Not bad considering the factory rated it at 25hp, and this at 5,000ft.

Currently the project is waiting on funds to purchase wide-band o2 sensor and data logger. Once I’ve acquired these, step 3 and 4 will be quick, and then more money will be needed for a flow bench in step 5. I’m just happy to have a tolerable time frame within which to achieve my primary goal: 100K

Right, now I have to scurry off and go do something productive. More to come, stay tuned!


About Dandooligan

Dandooligan CO, United States Every ride spurs the yearning for another and as such, has pushed me to adopt the riding lifestyle and all of it's challenges. This blog concerns those challenges from bikes to gear, media about bikes, and maybe even some psychology/sociology on the subject as well. Dandooligan, a mash-up of Dandy and Hooligan, both very important parts of me and my outlook on life. I'm also known as Spooph


  1. Nothing is impossible. If you haven’t already, check into what Burt Munro coaxed out of his Indian Scout’s engine. Don’t forget about weight reduction to get to your 40HP goal. 🙂 I wish I was as patient as you with the wrenching, I am however appreciating the knowledge I am gaining and I do see an increase in my efficiency, so I am getting better at it, even though it doesn’t feel like it at all. Maybe it’s the lack of a proper working space (read: garage) that makes me so aversed to wrenching. I don’t mind it, if I just keep in mind why I’m doing it, but this project of yours? Wow! Keep us updated, this is going to be good.

    I hear you on the expensive specialty tools. I buy them as I need them, but still. It seems that it never ends… I so would love a PCV with auto-tuning kit and LCD display, so I could get my geek on with some numbers. Which reminds me, I need to find out where there is a dyno around here. I need to get a baseline, too.

    By the way: There are two rules in motorcycling that you’ve apparently forgotten about:

    1. The quest for power never ends, no matter what bike you’re getting next. It is just temporary put on hold (until the new wears off).

    2. The bike can never be fast enough. And there is always someone faster. 🙂

    Good luck, Mr. Goodwrench. *grins* I know who I’m asking next time I’m stomped.

    • lawlz! Thanks for the encouragement! Yes, I tried very hard to forget those 2 rules, and you’ve dun-gone and reminded me again… 😛 I too don’t like wrenching, although there are certain things that make it more or less enjoyable, it’s still a chore and I’d rather be out riding….. Keep it rubber side down!

      Edit: Can’t believe I forgot to put this in here – I know about Burt Monroe, yes. In fact, he’s the man that gave me hope to try this silly little exercise!

  2. Kurt

    Two words… Tur bo. 🙂

  3. Kurt

    You can’t create horsepower out of thin air. (literally) At a mile high, your biggest concern should be getting more air into the carbs. Expensive, yes. But if you were able to map the ignition and turbo to come on above 8000 rpm, it would be livable as well. Just my humble opinion….

    • You are absolutely correct, but it’s a lot of work, and I’m not sure if it’s worth it. We shall see. I still have 60K to go, and a lot can happen in that time….

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