The first race of the year at Rausch Creek was a mud fest, but I managed to pull out a 5th place and a 1st place in the classes that I was running.
On Saturday practice went well and I was feeling good. My first race the bike died on the starting line but I was able to restart and take off way behind everyone else. About a half of a lap later the bike quit running – I had shattered a piston.
It is an understatement to say that I was devastated. By 1:00 pm on Saturday I had the truck packed back up and headed back to Boston.
Anyway, after I got the bike back together I noticed that the power band did not seem right. Sure, it has been 25 years since I rode a bike like this one, but my RM did not seem to have any bottom end, a weak mid range, then the power would hit like a ton of bricks and quickly sign off. In addition, no matter what I did with the jetting, the engine demanded race gas or it would ping. I never noticed this until after this rebuild because this was the first time that practice conditions were good enough for me to really run the motor hard (every time I went out before this is was gross outside). I chalked this up to me just remembering the good old days a little better than they were.
The next race for me was in Southwick, MA. This race was being run by ACR and all AHRMA members were invited. ACR has slightly different classes, so I ran in a Vintage 80’s class and a GP class. I had a BLAST, but the bike was really tough to ride and it seemed down on power compared to everyone else (along with the weird power band).
In the weeks after the Southwick race I decided to see what was up with the pinging on the RM. I started by really inspecting the electrical system to see if I had a timing problem or something. When I got to the CDI I noticed that it did not have the same wiring plug as was shown in my manual. Sure enough, I checked the part numbers for my stator, CDI and coil and found that THE ENTIRE ELECTRIAL SYSTEM WAS FROM A 1981 RM125!
Cripes, no wonder I could not jet the thing and no wonder it had the freaky power band!
Getting an entire electrical system for a 25 year old dirt bike was interesting to say the least. eBay saved my skin big time on this. I also appreciate the folks at On the Pipe Racing.. They sold me some parts and helped me understand what parts were interchangeable with my 1981 RM250.
By the time I got the RM250 put back together there were only a few weekends of riding left in the season. I really like this bike and want to continue to tune it to my riding style. Check back at my main page for any updates on this bike!