Maybe I signed off a little too soon. Since part 6 I installed a FMF Mega Bomb S/S header. This was the most dramatic change in performance I’ve done to the bike. The addition of the Rekluse was a comfort thing for me, so was the suspension for that matter. The bolt on horsepower increase was not cheap at $350 list, but the low to mid range torque increase was well worth it. My first butt dyno ride around my driveway was a holy cow!
The first ride in the dirt was at our SOTMC (Sierra Old Timers) ride day at the MMX sand track. I have a KTM 450SX Factory Replica (Dungy) that I’ve used for MX but as I’ve said previously I wondered if the 250FX can replace it. The 450 suspension was originally done by Factory Connection and was way too stiff for me so I had Bucky at SBB revalve it so this was my first ride on it since then. I decided to take the FX along at the last minute because of the new bolt on power.
The change in the 450 with the revalved suspension was dramatic and I really enjoyed riding it in fact I rode it most of the day. I did get the chance to ride a new stock 2015 Yamaha 250F and my 250FX back to back. Since my bike is set up for me and the 250F was stock the only real thing I was looking for was the difference in power between the two. There was a difference my bike had more low to mid range pulling power and less upper mid to top power than the 250F. The 250F did rev’d out quicker. The 250FX no doubt has different cams perhaps a little fly wheel weight and different ECU programming. It would be interesting to ride the stock 250F with a FMF Mega Bomb Header on it to see what the difference might be then. But for what I was doing both worked well just a little different. When doing any kind of off road riding though I have to believe the 250FX would have the advantage.
I rode the 250FX exclusively at MMX again the next week and then went to a marathon race in Fernley, NV that weekend. They ran the two MX tracks together for forty five minute races then had a team race in the afternoon. There will be an Old Timer International MX event held there in April so I wanted to get a little track time. It’s interesting the two tracks are sand and side-by-side but are different, one has traction and the other is like sugar sand and low traction.
My Fernley ride was fun but I struggled with the 250 in the deep sand, my arms pumped up and my hands went to sleep I couldn’t get on top of the sand. I swear this is the truth, I slept in my in closed bike trailer the night before the race and it moved around a lot, I have vertigo problems and it was bothering me so I put Sea Bands on my wrists to help with the motion sickness. They are very tight and have a sort of button that pushes on some nerve in the wrist to help prevent motion sickness. Well I forgot to take them off before the race and I have to think those things contributed to my arm pump and I’ve never hand my hands go to sleep while riding. That’s my story and I’m sticking to it.
The other thing that came in after part 6 was the IMS over sized gas tank that has been on order since I bought the bike. However it came without a cap. You have a choice of either a screw on cap or a dry brake system. And of course whatever you picked it was extra. The tank they sent was a 2.5 gal. Their web site is now advertising a 3.0 gal tank but in order to get an extra half gallon of fuel and with virtually no room under the seat they added capacity to the sides of the tank and utilized the radiator shrouds to hold more fuel. The nice thing about this tank is you get to keep the seat stock.
The tank they sent was a challenge to install, especially with no instructions. In order to install it you must remove the sub frame in order for it to fit in under the sub frame rails. They’ve utilized every fraction of an inch to ad fuel without adding any width to the tank, which is good but makes for a time consuming install. Turns out my tank is a pre production unit and required some tweaking here and there on my part and wasn’t intended for me at all. The tank was sent to Roseville Yamaha without any paperwork so everyone assumed it was for me, but it was actually sent through Yamaha Racing and was for Vaughn Wilk a sponsored rider, oops. The tank was designed for a dry-brake system only so when I installed a screw off cap on it one of the negatives is the cap became a potential nut buster. (Which it did) I may have to make a dry-brake system out of it in order to save my nuts. All this for a half gallon of fuel, eh, I think it will be worth it.
I’ve gone fifty miles a couple of time with the stock tank but didn’t think I had much gas left. (Turns out I had more fuel left than I thought) I think I should be able to get at least seventy five miles out the new set up when riding at a good pace for me; others may get less.
I tried the out the new Mega Bomb pipe and fuel tank at the fourth round of the Western National Hare Scrambles Championship held above Redding at the base of Shasta Dam. The course was twenty miles and the top AA PRO riders were making a lap in 43-44 minutes.
My race was in the afternoon and was in creditably dusty something the morning racers didn’t have too much of. An eighth row start, 30 plus riders in my row a first turn crash meant front fender viability part of the time. Another three falls on the first lap along with a brand new roll off system that malfunctioned, a camel back hose I couldn’t reach added up to a lap that couldn’t end soon enough. Then about three quarters through the first lap I caught up to the 2014 Dist 36 Master “A” (60 plus) class champion, passed him and shortly after that I caught up to the leader of my class, it’s amazing how inspiring that can be.
At the end of the first lap I came into the pits to clean my goggles and tear the rest of the roll off film off my goggles the bulk of it had wrapped itself around my rear sprocket. The second lap was almost dust free and a lot of fun, I could finally see. Instead of coming up on five or six riders at a time it was for the most part one at a time.
With a hundred and sixty riders either ahead of me at the start or on my row I ended up 79th on the first lap and 67th overall at the end, first in my class and 2nd in Master “A” class not bad.
The bike worked perfectly, the only issue I had been on the long down hills I over heated the brakes, front and rear. With the 250 not having a whole lot on engine braking in the first place then add the Rekluse it felt like I was just freewheeling it down those hills sometimes. Spooky when you’re used to engine braking. But the first lap had some bottlenecks and the Rekluse more than made up for it then.
After a little over forty miles of racing on a course that was both very fast and very slow at times I had plenty of fuel for the two laps but I don’t think I could have completed another one.
As of this writing I have 36 hours on the 250FX.
Doug 21J