Herb Becker visits after Andy’s 154mph Bonneville run

lcrken said:

157.09 mph is the SCTA record in 1000 M-PG class. The funny part is that the record in the fuel class (1000 M-PF) is only 150.15 mph. If they had run in that class instead, they would have a record! If you look through the record books, you will find a lot of cases where someone has set a record in the gas class, and then set another record in the fuel class, with no change to the fuel used. All you have to do is declare that you are running in the fuel class. The only difference is that they don't seal the tank in the fuel class.

Ken

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There is a bit more involved than just declaring you are going to run the fuel class; You need to set up a handlebar-mounted, thumb operated remote fuel shut off (I believe the official rule is something like "fuel shutoff to be operated without rider removing a hand from the handlebar"), and also have flame-proof coverings on all fuel lines. You have to pass through tech a second time, with these proper "Fuel" class modifications, and also pay a $200 fee to change classes. That being said, we will be sure to bring the right equipment to set up such a shut off mechanism next year.

Herb told me that you were getting a little more RPM when you backed off the throttle a tad. Maybe you were too rich and leaning in out by dripping the needle into the jet. Herb is thinking that the carbs are too big. Sounds like there's a little more to be had.

Dances with Shrapnel said:

I'll suggest it, as with JimC., the motivation is theirs. I'll be chatting with Herb after he returns home.

Keep in mind that a lot of the elements to good tuning practices have already been published.

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Many people who are involved in competition keep their tuning secrets to themselves, however those who are willing to share work for the greater good. Let us be honest, if you own a bike such as my Seeley 850, it has limited use - because very few race classes exist in which it can compete on a level playing field. The main reason is that there are not enough similar bikes, because guys don't know how to build them to a reasonable standard. And to buy a competitive one is prohibitive. When I discuss what I know, I hope it helps make others race faster - I will still beat them because I am never going to crash. - Same with Herb Becker. There are some guys who race, that if you see them on the start grid beside you, you know you might as well go home. I think Doug MacRae and Kenny Cummins would be interesting to race against.

Eldo said:

There is a bit more involved than just declaring you are going to run the fuel class; You need to set up a handlebar-mounted, thumb operated remote fuel shut off (I believe the official rule is something like "fuel shutoff to be operated without rider removing a hand from the handlebar"), and also have flame-proof coverings on all fuel lines. You have to pass through tech a second time, with these proper "Fuel" class modifications, and also pay a $200 fee to change classes. That being said, we will be sure to bring the right equipment to set up such a shut off mechanism next year.

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True enough. I wasn't trying to say you should have run a different class. It just struck me as weird that the fuel class record was lower than the gas class record. The fuel shut off requirement slipped my mind. When I first switched my bike from a road racer to a landspeed bike back in 2000, the way I had the fuel system set up meant that I couldn't easily reach the valve while on the bike, so I had to go with the bar mounted fuel shutoff just to be legal, regardless of class. When it turned out that we had time left after setting the gas class record, I decided to also run in the fuel class, and all I had to do at the meet was sign up for another class anad go through tech. And pay the fee, of course. The fee for an additional class was lower back then, but it still seemed like a lot at the time.

However, the flame proof coverings on fuel lines requirement isn't unique to the fuel class. It applies in both gas and fuel classes, or at least that was the case in the 2017 rule book. I haven't picked up a copy of the 2018 one yet. The actual requirement is "All non-valve portions of fuel or gas lines (including saddle tank crossover lines), shall have fire resistant or fireproof connecting lines and fittings. Aeroquip fire sleeve cover meets this requirement." I was never quite sure how the tech inspectors were going to interpret what was the non-valve portion, so I just put heat shield on all the lines.

Ken

jseng1 said:

Herb told me that you were getting a little more RPM when you backed off the throttle a tad. Maybe you were too rich and leaning in out by dripping the needle into the jet. Herb is thinking that the carbs are too big. Sounds like there's a little more to be had.

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It is normal to have the main jets too rich, simply for safety. How would you do plug chops to get the main jets lean with safety, at Bonneville ? If you did it somewhere else, you would probably not replicate the conditions you would encounter at Bonneville, so you would always have risk when the main jets were lean enough for the motor to give it's best.

jseng1 said:

Herb told me that you were getting a little more RPM when you backed off the throttle a tad. Maybe you were too rich and leaning in out by dripping the needle into the jet. Herb is thinking that the carbs are too big. Sounds like there's a little more to be had.

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Yes, there where times when I actually seemed to loose rpm at full throttle, picking it back up by rolling off just slighty. In these instances, our data seemed to show us running lean at full throttle. Under rich conditions, the rpm stumbled with misses. Herb does feel the carbs are too big, providing lots of volume, but not enought velocity. They work great on short 1/4 mile runs, and even into the mile, but over the 2-3 mile lengths at Bonneville we needed more velocity. With increased velocity, we could decrease Main jet size.