Dave Roper Racing: Carolina Motorsports Park

The AHRMA event at CMP was a weekend of two halves. My 350 Sprint ran great and I won both races on it. My 250 Sprint was lots of trouble and netted a DNF and DNS. My 250 hadn't run for almost two and a half years since it dropped a valve in Oct., 2014 at Daytona. Karl Engellenner renewed the complete top end, working on it between his many projects. This involved welding up and machining the head, new valve seats, valves, guides, springs and retainers, new intake manifold and carb bell mouth, new exhaust head pipe, new cylinder and new piston. The piston was a big delay as it took about 9 months for J.E. to produce it. I started it up for the first time the Sunday before I left for CMP on Thurs.

When I got to CMP early afternoon Fri., I started the 250 and found that the Smiths chronometric tach didn't work. As soon as the cable spun, it would go from 0 past 12,000 rpm and stay there. I took it apart, but was completely overwhelmed by the gazillion tiny gears, springs and levers. Dave Hollingsworth and Beno Rodi took a look at it, but to no avail. So, I stole the tach off my 350 and put it on the 250. I then took the bike to the Hall Custom Vintage dyno. Jake and Rob Hall bring a Dynojet in a trailer to the track and I wanted to get the timing and jetting close before putting the bike on the track. We made one run and the 'sniffer' indicated that it was a bit rich and Rob, looking at the sparkplug, thought the ignition was a bit advanced. In retarded the ignition a bit, but Jake noticed that one of the cylinder studs was flopping around. We removed it and found that it was broken off in the crankcase, which seemed better than the threads pulled out of the case. Everyready Al Hollingsworth had a spare stud that was only slightly longer that my brokren one. Now the challenge was getting the broken off end of the stud out of the case, as it was broken off below flush. Rob had a left hand drillbit with him and, drilling into the stud got it it move a bit. I was able to borrow an e-z out, and the broken piece came out without damaging the case.
But, when we removed the head, we saw that the intake valve had touched the piston both on the edge and floor of the valve pocket. I borrowed a Dremel tool and burrs that Rob used to open up the valve pocket a bit and while I got thicker base gaskets. We also set the the valve lash a little looser.
I got out for Saturday morning practice a little late and only got two laps in the first session on the 250. I took it super easy both out of concern for a fresh engine and because the tires on the bike were really old--the rear from the 35th week of 2008 and the front from the 47 week of 2004. They are the Dunlop KR 825 front and KR 124A rear, neither of which are made any more, and both my preferred tire, so I wasn't going to throw them away without trying them. They weren't a problem at the speed I went.
Bobby Birdsall loaned me a spare Scitsu electronic tach which I put on the 350, but it's battery wasn't charged, so it didn't work in the 1st session.

Bobby Birdsall's Scitsu tach on my ERTT

I took it pretty easy on the 350 also, as the tires on it weren't that old but were very worn. But, the motor ran great. For a while, I had been chasing a carburetion problem, a stumbling or miss fire in hard cornering, which I finally figured out at Roebling Road was not a carburetion problem at all, but an ignition problem. The ground plug, which the Harley factory put on the bike in 1970, had evidently worn enough that it made intermittent contact in hard cornering. I install a new, similar plug and the problem was gone.
In the second practice on the 250, I started to wick it up more and the tires were still working fine. But, towards the end of the second lap, I lost my clutch release and decided that I didn't want to ride with a fresh engine and not being able to disengage the clutch, so I pulled off. Turns out that the handlebar adjuster had just backed off and a bit of safety wire cured that. I was able to get the bike back on the HCV dyno and we retarded the timing, then retarded it again, but that was too much, put it back then dropped one main jet size.
The 350GP race was first for me and we were gridded behind the 500GP class in the first wave with the Formula 500 and Novice Production Heavyweight in the second wave. I got a good start and led into turn #1 and led overall for a couple of laps. Then the F-500 bikes started to come by, first Dean Middleton followed by Mark Morrow, both on RD400 Yamaha based bikes, then Jim Hinshaw on his H-1 Kawasaki. Dean's motor seized and Hinshaw got by Mark. On the last lap, I heard a bike behind me and coming out of the last corner, Alex McLean came by on a 500GP Manx Norton and out dragged me to the checker. So, I was first 350 GP and 4th overall.
For the 250GP, we were gridded in the second wave with Vintage Superbike Lightweight, Sportsman 500, and Novice Production Lightweight in the first wave. When the first wave left, there was a crash in turn #1 and the second wave wasn't flagged off and we were returned to the pits, as there was a considerable delay. Eventually, we went out for a second warm-up lap and this time the the race got off OK. I followed Juan Bulto into turn #1 and initially thought that his air-cooled TSS Bultaco wasn't that much faster than my Sprint (though who knows how far he was opening the throttle). He pulled away steadily, but that seemed to be more a matter of corner speed than power. He's an excellent rider. I seemed to be a comfortable second in class until the 3rd lap when the motor misfired some and lost power and I pulled off at turn #12. DNF, but not last as Robert Brangaccio broke before I did. I found that the ignition stator had come loose and cocked, touching the rotor. Some Loctite on the insert that the stator bolt goes into cured that. I also noticed that my remote float bracket had broken, allowing the float bowl to flop around a bit which probably accounted for the motor surging or hunting at times. A couple of hose clamps effected a bodge repair.
Saturday evening, one to the AHRMA officials celebrated his birthday by putting on a BBQ open to all. I was good food and a good smooze.
In Sunday's first practice, I only got less than 2 laps before the motor started misfiring and I pulled off into the pits. This time I found a coil wire had come loose and was making intermittent contact. I pushed it back on well and taped it. I just did a couple of laps on my 350 to check that it was OK and not use up to much of what little tire I had left. I took the 250 out again for the second practice and on the second lap, missed a shift and the motor went sick. I found that I had bent an exhaust pushrod and I replaced it with a spare that I had.

But, then I found that I had no compression and removing the head revealed a very bent valve, for which I had no spare. Game over.

the cylinder head removed from the CRTT

bent exhaust valve

On the 350, I again led overall for a lap or two until Jim Hinshaw came by from the second wave with his H-1. He pulled steadily away and finished almost 15 and a half seconds in front of me. But this time, Mark Morrow didn't catch me and I finished more than 16 seconds ahead of him. For some reason, Alex McLean pulled off after three laps, so I was first in class and 2nd overall and my fastest lap was almost 1 second faster than Saturday.

the front tire on the ERTT after Sunday's race

the rear tire on the ERTT after Sunday's race

Stu Carter had brought his 200 Honda, which he had just put new carbs on and he put it on HCV's dyno and the sniffer showed that it was way rich. Stu decided that he wasn't going to race it and that I could in the 250GP. I went looking for smaller jets but was only able to find ones slightly smaller from Miles Fredrick at Street and Competition Cycles. While not ideal, I figured it was still worth trying to race it to shake it down. But, when the time came, the motor didn't want to turn over as it evidently leaked fuel past the float needles and hydraulic locked. We pulled out the spark plugs to try to clear the cylinders, but then noticed that the fuel tank was leaking, so I didn't start.

Stu Carter loading his ill fated 200 Honda

Despite the disappointment of the 250, I enjoyed the weekend as the weather was gorgeous and I enjoyed the track more than I had remembered, having last raced there 11 years before in 2006.