Topic: New 750's in the 70's going to the drag strip, what was changed?

[Don R]

 I was wondering what things were changed (if anything) when taking that nearly new cb750 to the track? I'm wondering if the baffles were removed, jets, sprockets, timing or anything like that? I saw the ET list from back then and it got me thinking.
 I had a K3 750 back then but never raced it. My brother's bike (750 K4) did take home a couple trophies, he ran it the same as the street with a 4-1 hooker header and a set of bigger main jets. 

[MRieck]

I was wondering what things were changed (if anything) when taking that nearly new cb750 to the track? I'm wondering if the baffles were removed, jets, sprockets, timing or anything like that? I saw the ET list from back then and it got me thinking.
 I had a K3 750 back then but never raced it. My brother's bike (750 K4) did take home a couple trophies, he ran it the same as the street with a 4-1 hooker header and a set of bigger main jets.

The Hooker headers for the 750 and Z1 were some of the best ever made. They actually dynoed the bikes etc. Stetson's pipe of choice throughout his CB's career.

[Shtonecb500]

I was wondering what things were changed (if anything) when taking that nearly new cb750 to the track? I'm wondering if the baffles were removed, jets, sprockets, timing or anything like that? I saw the ET list from back then and it got me thinking.
 I had a K3 750 back then but never raced it. My brother's bike (750 K4) did take home a couple trophies, he ran it the same as the street with a 4-1 hooker header and a set of bigger main jets.

The Hooker headers for the 750 and Z1 were some of the best ever made. They actually dynoed the bikes etc. Stetson's pipe of choice throughout his CB's career.

I have a set of hooker pipes that came on a bike i bought, I took them off and replaced it with either a real or replica david dixon 4-1. I took off the hookers because they are missing the baffles and have a lot of surface rust....maybe i should find baffles and get them refinished.

[Don R]

 I always watched for a vending machine that sold V8 juice, the cans were steel and when punched with a church key the right number of times, made a really good baffle for a 4-1 hooker with no muffler on it. I bet a hooker with a Cone brand stainless muffler would be awesome.
   I have a big bore K2 with a really nice hooker 4-2 but a run up to a hundred mph may have removed the packing. It used to sound like an Indy car when it was on a stock bore engine. I'm afraid to try to take them apart for re-packing, they may be all rust inside, or even empty shells. 

[Old Scrambler]

Baffle Size............If the V8 can was a snug fit; the ID of the mega was 202mm

[Don R]

 These were the single serving V8 juice and installed into the collector because the megaphone was rusted out. Midwest cold air condensation and short trips caused a lot of rust. 

[newday777]

Hooker 4into1 on my K5. I sold this hooker to the original owner in 1976.

[Don R]

 A classic never goes out of style.

[Laids]

This pic is circa 1974, Henry Abe 900, Kenny Harmon D grind cam and a Hooker Header. Took it to the drags a few times, my best time was a 12.4 @ 107, in more experienced hands I’m sure could be better. It was always a great running bike. At the track I would take the baffle out and jet up. After a day of racing, put the baffle back in , jet down and ride 125 miles back home.
One of the issues with the Hooker was low right turns.

[Don R]

 It's funny Laids, that's the bike I want. I almost have it, but it is short the 900 kit, the RC 836 in mine got rusty in the barn and is a smoker. 

[T1m32sh1n3]

Ive got henry abe 900 pistons, rings, pins and circlips nos. If your looking.

[HondaMan]

Gearing.
The K2-K6 bikes got a 17T front sprocket and often a 102-link (sometimes 104) chain to move the rear wheel back a bit.
The winners around my shop's area in those days were using Conti tires because they had more rubber grip than Bridgestone, but less than an all-out drag tire.
Mostly Hooker headers were eek-ing out a tenth or so, but the top racers I knew had HM300 pipes sans baffles. I suspect he also had a K0 engine with 52T rear sprocket, 16T front, but in a K3 frame, running Action Fours 825cc kit in 1972 and their 836cc kit in 1973. I left the area in summer 1973, lost track after that. He said he had the 'stock cam', was in the low 12 second brackets, everything had to be street-legal (including turn signals, being Illinois...).

[Don R]

 This bike was running in Central Illinois back then. The PO still races a Hayabusa.

[HondaMan]

Lesters!
Nice wheels.

[Don R]

  The back one is an 18x3, I was tickled to get it. I put on the speed rated radials for the Rantoul half mile race but it got cancelled. Turns out not to matter, the top end needs a freshen up. It lived in a barn for a couple years with the carbs off. I was shocked when it rotated and was hoping to be lucky. I'm thinking it wants to be an 890.