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Author Topic: Dakota's 2010 Race Reports - Jennings GP  (Read 6967 times)

DakotaCBR

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Dakota's 2010 Race Reports - Jennings GP
« on: April 08, 2010, 09:50:17 PM »
Racing with CCS Ė April 3-4

I made a very much impulsive decision to sell my 600RR trackbike and purchase a 1998 Honda RS125 two-stroke machine to be my new road racer. Working with a two-stroke is a huge learning curve. The powerband of the bike is basically between 10-12k RPM, and if the needle isnít in between those two points, the bike WILL NOT go anywhere. Corner speed is the name of the game riding one of these little guys. Not only do you basically have to learn how to ride a motorcycle all over again, but you have to learn how to tune the bike as well just so you donít seize the piston in the cylinder. A weekend on a two-stroke basically goes like this: Wrench, ride, wrench, ride, %*#(%&*!!!!, wrench, wrench, ride, wrench. The tuning doesnít end.

My buddy Joe and I headed up to Jennings GP Friday night and set up, then headed out on a wacky expedition to find a hotel room. The next morning we got to the track at 7am so I could get the bike through tech and go over some last minute items. The drill we brought with us was not powerful enough to turn the bike over with the GP starter tool, so Joe ended up having to bump start me every time I went out. After some pushing and bringing the bike up to temp by blipping the throttle for a few minutes (most two-strokes are not set-up to idle, you have to blip the throttle to keep the motor running), I took the bike out for the second practice session of the morning and proceeded to get my bearings with it.

The bike is tiny. Like, really really tiny. Luckily I am able to fit into the bubble, but not by much. The first session I figured out that I canít ride the bike unless Iím atleast over 10k on the tach. This would have been fine, but I put in a large main jet to be on the safe side for my first time out on the bike. Well, a big main jet in the carburetor means that the bike wouldnít rev past about 10.5k. After the first session I came in and dropped two jet sizes and checked over the spark plug.



The next session I tried to figure out some shift points. Two-strokes basically have no engine braking, and you can slam down as many gears as you want and dump the clutch out without any rear wheel hop. Blowing into 3-4-5 and dropping 4 gears was pretty damn cool. When I came through T8 in second gear though, the bikeís RPM dropped to about 8k. I rolled on the throttle, the bike pretty much fell on its face, and my helmet bumped into the windscreen. Like I said, the bike does not go unless you are up in the power, but when you get the revs high enough, this thing is a freaking ROCKETSHIP. I worked on shifting for a bit, then came in to tinker on the bike a bit more.

The third session I left the carbís enricher on and forgot to close it before I went out. The bike would not rev past 7-8k. Thinking I busted something up, I came back in to the pits. After figuring out the problem and kicking myself for losing more time, we changed out another jet size for the next session. However, on the next session the bike was starting to give me some terrible intermittent power delivery problems. The bike would rev into the 10-11k range and the tach would start to jump around. I thought it was going to throw me off a few times. It was so bad that I just plain could not improve anything until I got the problem worked out.

A quick call to my buddy Eric in NJ (the guy who talked me into buying one of these blasted two-strokes) had me checking out the needle position and power jet solenoid on the carb. It was determined that the solenoid was bad, causing the jittery power delivery problem. I decided to call it a day and look for someone with a carb in the morning. Thankfully, it was a USGPRU weekend and I did find someone with a 98 RS125. He let me pull the carb out of his bike and use it for Sunday! In morning practice, the problem was immediately gone and I was going faster in the first session of the day than I had been all day on Saturday.

Race 1 Ė Amateur GTL

The GTL is a 9-lap race with the lightweight bikes Ė SVs, Buells, Motards, and 125GPs. I tried to figure out how to launch the bike in practice with no success, so I decided that Iíd just pin the throttle at the drop of the flag and feather the clutch out until I was basically in T1 (I would later learn that this is, in fact, how to launch a 125 two-stroke. Yes, I did purchase a spare clutch pack). I was basically using this race as more practice. I finally figured out my shift points and started getting more comfortable with the incredible amount of lean angle that the bike likes to have. I ended up finishing in 6th place.

Race 2 Ė 125GP

The 125GP race is a combined amateur/expert race. USGPRU was there so the grid was full of people who know how to ride these machines well. Crap, 13 year-old Peter Lenz was doing 1:18s on his 125. There was no way Iíd be finishing well in this race. I did get a decent spot on the second row of the grid though, so that was a welcome change from post entering and starting in the back.

Ever watch the start of a 125GP race? The green flag drops, and nothing happens. Thereís no wild bucking or wheelies; it just sounds like a bunch of weedwackers slowly increasing in RPM until they hit the power band. Some people even try to waddle the bike forward at the start to get some more momentum going. I actually did get a decent start, but after T2 the rest of the field was pretty much gone. I just worked on putting in some good laps and learned a bit more about corner speed. I ended up putting in my fastest laps in this race, although they are nothing to write home about. I didnít get lapped by the leaders though, so Iíll take that as a small victory. The race was combined with the Singles GP and Ultralightweight Superbike races. I ended up 6th in the 125GP class and 8th in the overall combined race. Not too shabby all things considered.



Afterthoughts Ė

This bike is a lot of work. After the races on Sunday Iím actually pretty happy with it though, so Iíll keep it around for a bit. Entry speed needs some work, as well as learning how to tune the bike. Iíd really like to get in a trackday on this thing to learn a bit more about it (wink, wink). Itís a lot different from riding the 600, but I think Iíll be going around the rest of you diesels in the corners soon enough ;-)

Thanks very much to my 2010 sponsors: Lithium Motorsports, ScorpionEXO, Trackdaymag.com, and Woodcraft. Itís been great to work with these companies in the past and Iím really glad Iíve had their support in this endeavor. Also thanks to my buddy Joe for being my crew chief this weekend, Mr. Eric for the tuning advice, Mike for letting me borrow his carb, and to the fine staff of CCS and Jennings GP!

Next round I can make is going to be Roebling Road in July!!
CCS FL #308

Lithium Motorsports      ScorpionEXO      Vortex      Trackdaymag.com      Woodcraft

Jason748

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Re: Dakota's 2010 Race Reports - Jennings GP
« Reply #1 on: April 08, 2010, 10:43:49 PM »
Way to go!  Sounds like you're acclimating well to the 125.  But you still look like a monkey fucking a football  :P
Brings back memories of my 2-smoke days...
CCS/CRA #92
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Sponsors: Two Brothers Honda, Lithium Motorsports, SpyderLeatherworks

"A lot of people go through life doing things badly. Racingís important to men who do it well. When youíre racing, it... itís life. Anything that happens before or after... is just waiting."  -S

UKTURFROCKS

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Re: Dakota's 2010 Race Reports - Jennings GP
« Reply #2 on: April 09, 2010, 07:10:42 AM »
thats greeat hatch.  love the pictures
someone tried to steal my katana last year, then they realized it was a katana and stopped, then ran it over with their vehicle..  quote from *~c_dubya~*

Nihon Newbie

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Re: Dakota's 2010 Race Reports - Jennings GP
« Reply #3 on: April 09, 2010, 07:37:02 PM »
Sounds like a hell of a challenge, that's for sure, but glad to hear that you're having fun with it, and hell, not doing to shabby in the races either!   ;D

I'm also totally jealous, of course.  Riding that thing looks absurdly fun!   8)
1972 CB100 K2 - Fully Restored || 2008 CBR600RR - Street/Track || 1985 CH150 - Under Construction || 2007 CBR600RR Street/Track - (Sold: May/2011) || 1982 Urban Express NU50m - (Sold: May/2011) || 2006 CBR600RR - My First Bike (sold: 05/2007)

beer

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Re: Dakota's 2010 Race Reports - Jennings GP
« Reply #4 on: April 09, 2010, 10:11:47 PM »
Way to go!  Sounds like you're acclimating well to the 125.  But you still look like a monkey fucking a football  :P
Brings back memories of my 2-smoke days...

I'd like to see you on it, would that make you an elephant on a bicycle?

Jason748

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Re: Dakota's 2010 Race Reports - Jennings GP
« Reply #5 on: April 10, 2010, 09:25:09 PM »
There's a reason I swapped to a 250 after 1 year on a 125...  :)
CCS/CRA #92
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Sponsors: Two Brothers Honda, Lithium Motorsports, SpyderLeatherworks

"A lot of people go through life doing things badly. Racingís important to men who do it well. When youíre racing, it... itís life. Anything that happens before or after... is just waiting."  -S