The springs seem to break with abuse and age. The easy way to fix it is to replace it with a used one from another parts motor. I don't believe that you can rebuild one without a lot of research for spring replacements that Honda doesn't offer seperately. Losing one every 34 years or so, doesn't make it a rapidly failing part.
Dragracer: -The goals aren't mutually exclusive. You can run quicker than the 12.40's that this Hondamatic has gone and still be very consistent. I've run 11's at Prostar events with two successive rounds of sub .030 packages with my Hondamatic drag bike. For Street ET, you can win a lot of rounds with sub .050 packages.
The problem that has been created is the marginal rear brake setup for the current combination. When you improve the lower end powerband, you increase the forces against the rear brake. The current hand held rear brake pressure won't hold the bike consistently on the starting line while the tree comes down. When they chose to put the bigger displacement into the bike, they created this "new" problem. The "fix" is for a stronger braking system to hold the increased power. I've posted that the foot pressure will be greater than your left hand can create. A line lock will hold the peak pressure of whatever is applying the pressure. Air/foot/hand or any combination of them. I've recommended using a foot master cylinder to generate enough pressure to hold the bike on the line while the tree is coming down. (foot pressure through a line lock is all I've used for 11 second ET's) The front brakes have nothing to do with launching a Hondamatic off of the starting line. You can't be consistent launching a bike while doing a burnout on the starting line. Get more pressure to the caliper and see if it holds. If it doesn't hold, you next look at replacing the caliper to get more clamping force on the rear disc. The easy way to test it is to put the bike on the centerstand and mock up a launch. If the rear brake holds the rear wheel still while it's in the air under full throttle for 1.5 seconds, you've got your brake problem fixed. The desire to give Sam an 11 second time slip created this unintended problem.
My only involvement with the effort has been to dial the bike in at Valdosta. Last November, Sam ran a 12.99 on my 12.98 dial and a 13.02 on a 12.99 dial. (The setup didn't allow me to dial above a 12.XX, so I couldn't go 13.01) That was when the bike was cold, which is about .5 to .6 slower than it runs warmed up. The next challenge will be the rear tire if they continue to improve the power. I had to go to a slick when I got to the mid 11's. To stay in Street ET, there are DOT slicks available that the quicker bikes use. It would require a different rim; possible offset front sprocket and possibly a wider swingarm. I suspect that the efforts will slow down to run quicker due to budgetary constraints....
We've already seen back to back passes that were .001 apart to the 1/8th mile timing lights with Bill driving. Give me a brake that holds the bike on the starting line consistently, and I'll show you time slips that match sliders with autoshifters. The bike will be quicker with the 295 cam and the "old" carbs back on it this November. We just need a rear brake system to hold it at the starting line.
Jon Weeks
