Posts
1128
Joined
2/7/2007
Location
El Dorado Hills, CA, USA
Edited Date/Time
1/25/2015 3:39am
I bought a clean '94 yz125 a while back and decided to make an Emig replica bike, if possible. The 1994 model was a great find because it already has the purple frame. I contacted k-rae graphics and threw it all together. The seat cover was impossible to get so I had Ceet make me a one-off (as-close-as-it-gets) seat cover. I supplied the materials from my local upholstry shop and shipped it to Ceet to stitch and print.
The bike has a ported 96 cylinder, power valve governor and actuator arm. I epoxied the cases to match the transfer ports. I also installed a boyesen rad valve, pro circuit pipe and shorty silencer.
The bike has way better mid-range pull but still requires a lot of clutch to keep it on the pipe. I would love to fit a newer engine in the frame but that's low on the priority list.
Hope you guys like it!
The bike has a ported 96 cylinder, power valve governor and actuator arm. I epoxied the cases to match the transfer ports. I also installed a boyesen rad valve, pro circuit pipe and shorty silencer.
The bike has way better mid-range pull but still requires a lot of clutch to keep it on the pipe. I would love to fit a newer engine in the frame but that's low on the priority list.
Hope you guys like it!
I really liked the graphics and colour scheme they ran that year.
Very cool build
The Shop
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Luxon 4-Post Bar Mounts
$189.95 - $239.95
Heres a pic I shot of him at 'shougal, 95" I believe.
Notme, this is Damon Bradshaw in 1993. I actually have some awesome video footage I took of that particular race from the mechanics area. I believe this was one of the only 125 races for Bradshaw after he was on the 250. I think Washougal was the first round of of the 125/500 national, after the 250 class wrapped up. I may be wrong, but I think they split the 250 and 500 cchampionship throughout the one outdoor national season. There could be two champions (a 250 champion and a 500 champion) for the year.
Notme, this is Damon Bradshaw in 1993. I actually have some awesome video footage I took of that particular race from the mechanics area. I believe this was one of the only 125 races for Bradshaw after he was on the 250. I think Washougal was the first round of of the 125/500 national, after the 250 class wrapped up. I may be wrong, but I think they split the 250 and 500 championship throughout the one outdoor national season. There could be two champions (a 250 champion and a 500 champion) for the year.
Move the fitting of a newer YZ engine up on that priority list
Thanks for the compliment.
The 94 had great low end midrange but was totally flat on top stock.
The 96-01 is still the 94 motor, really...just better tuning from the factory.
Pit Row
The 1994 was the first year of the guilotine power valves. In 1995, they moved the valves 1mm closer to the piston and 1mm lower. Yamaha also made the pieces thicker, for more sealing surface. The '94 valves are pretty much sharp where they meet the piston. The 1995 also got a new carburetor. I believe '96 went much wider on the power valves (width wise) and raised the primary compression (new cases), straighter intake tract, and larger chamber volume under the power valve cover. They also went to a new actuator assembly (moved the spring onto the pv rod under the cover).
Reminds me of my 1987 YZ80 and my first ever (4th place, novice) trophy!
I agree with the smooth powerband on these bikes. I had a '97, '99, '02 and currently '05 and the '94. All easy to ride except the 94. I have a gopro video of my '94 (still with the '94 cylinder installed) I will post when I get a chance. You can hear the engine bogging everywhere.
A side note: The piston ring from Wiseco comes with .024" gap for "reliability". I will install the Honda/Suzuki ring soon to see if it helps.
In 01 they went to the 38mm carb, right? Did they change the pv at the same time to compensate for less low end? I have had a 04 and have a 97 project now and I totally agree about the smooth power curve. They also seem to be very reliable.
I'm looking for a Rinaldi engine kit for mine to make it scream
I see clarke has white YZ tanks for stock capacity I'm guessing that is where MXM got his. Only thing I heard bad about clarke is the white can be a different color from the plastics.
Here is a photo of my bike (crappy cell pic). Wish I wouldn't have rushed through the build as the hubs/engine are still quite dirty. I was on a budget still need new tires/brakes/rotors/chain. Wanted to get a new blue tank just couldn't justify spending $200, then spending another $100 on a new seat. I saw a black gripper seat on CL around here for $50 unfortunately it is too far same goes for the blue tank unused $100. Guess I can always get those things in the future.
I think you're on the right track with the jetting for starters.
The only hop-up info I read was from Eric Gorr's Forward Motion book. If I remember correctly, he says to lower the outer edges (and maybe widen) the outer edges of the exhaust port one millimeter. (Not to exceed 95% of the width of the cylinder so be careful.
Also, you can raise the exhaust port to 28mm measured from the top of the cylinder. This measurement seems to be typical on all 125cc engines with 54.5mm stroke/54mm bore. If you raise the exhaust port you may need to mill the head to bump the compression ratio back up.
Other than that, I think you can add an FMF shorty to match your pipe.
Here is my 97
Found an alu tank for it recently and also have Öhlins shock and forks coming
Obviously MX is taken pretty serious there. I never see aluminum tanks and hand welded exhaust on bikes in the US outside of a National or SX
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