What a SUCKY Day
Last race in November we burned up the gears when the bolt in the weep hole came loose and ported out the tranny fluid. I most of the replacement parts for the gearbox (shafts, gears, bushing, forks, etc…) but our engine builder did not get the additional three parts we needed (a main shaft, a bushing and a shiftfork) in time for this weekends race. Found that info out on Thursday afternoon so I was scrambling to find a motor we could use. Another racer who had moved up from a 125 motor to a 250 had one he let us use.
Got that motor late Thursday night and I got it mostly mounted Friday evening. Had to instruct out at Phoenix International Raceway on Saturday so it was a sprint Saturday night to complete mounting this motor to our kart. Got “done” just after midnight. The sky looked ominous so before heading to bed I checked the weather report and saw that the forecast was for rain all day long.
Alarm goes off at 6:30am and first practice is at 9:30. Decide to skip it since it will be cold and wet. Got dressed but took a nap for another two hours before heading to the track.
We know our kart runs (qualified third at the November race) and we know this motor runs (it qualified 10th and finished third at that same race) but the two have never run together so rather then go out for second practice I just took the time to go over the kart again and double check everything and finalize any issues.
Tyler test drove the kart in the paddock and everything seemed ok for the most part. Had to shorten the shift linkage to get the shifter working properly. Testing in the paddock Tyler could upshift fine. Downshifts were a problem. Got that issue fixed. Since our kart still had the same setup as the last race on this track and the last time this motor had been run was on this track we figured we would be fine for qualifying.
Got Tyler started and he drove to the grid for the qualifying session with no problem. On the grid I noticed that the chain did not seem to be lubed. Told Tyler to drive back to the paddock so we could get it oiled up.
Once the chain was lubed I tried to push start him but the kart would not start. While it was in gear I was able to push him like he was in neutral.
Checked the linkage, clutch and clutch cable and it all looked ok. Tried to push start him again and this time it started without any issue.
Kept the kart running on grid to get it warmed up and off he went when the track went green.
Got in four laps and then I did not see him again. Walked back to the paddock. Not there. Got in the truck to drive up to the carousal. He was off with another kart. They had not crashed, they were just parked broken down together.
While I was asking Tyler through the fence what the issue was he said it had just stopped running. While talking to him and his looking over the kart he noticed that the spark plug wire had come free from the solenoid. He pushed it back in and got the other racer that was off track with him to try and push. Same issue we had seen headed to the grid. Pushed like it was in neutral.
Tyler came in on a flat tow and we proceeded to try and figure out the issue.
Thought maybe the clutch was engaged and disconnect the clutch cable. Nope, that wasn’t it. Talked it over with eight other racers and nobody could figure the issue out. Thought maybe it was the piston ring and maybe we just weren’t getting enough compression.
Pulled the head and the cylinder. Piston and ring looked fine. The cylinder looked fine too. Put the motor back together and tried it. No dice. By this time we had five of use stripping down and rebuilding the motor trying to figure out the issue.
Finally discovered that when we turned the motor over we could hear two compression pops and then silence followed by two compression pops and then silence again. Almost like the clutch was slipping and not moving the crank. If we round a strap around the rear tire and pulled to rotate the tire there would be a little bit of resistance (due to compression) then the motor would turn over freely again like the clutch was slipping.
Crap. Put the kart and gear away and watch everyone else drive out to the grid for the race.
Even with no practice time and only three laps in qualifying Tyler would have qualified sixth for the race.
Oh, well… There’s next month if we get our motor back and figure out what is wrong with the motor were we using.