1977 TT500 Yamaha master builder Swede Johnson
Posted: Fri Jul 06, 2012 5:01 am
Swede Johnson is a long time racer and builder.
I first met Swede when I was selling parts out of my garage about 10 years ago.
He needed parts for a TT500 and I had a few laying around.
Here is what Swede started with:
Here is some engine work
Here is some of the end results:
Here's some words from Swede himself on the build:
I need to bring everything up to date. The bike is now in what we call stage 4 condition. First (original) bike had the engine in stock position in the frame with a mild cam and re-worked head i`ll send pics. of. Stage 2 the engine was installed in our modified frame to be vertical, not inclined per stock. This was so I could do a more radical head with more downdraft angle and more offset for better swirl and large valves and intake tract diameter (picture of engine you have is this configuration) and welding fins to head to increase cooling. A better cam was designed and ground and a 90mm sleeve installed in cylinder. Carillo rod and other items for reliability installed and a 38mm Mikuni flat slide installed. I also installed a Lucas competition magneto and a 41/2 lb flywheel along with a flat plate side cover/mag mount for better revving . A 10:1 Wiseco piston installed. Then we decided to see how far we could take it (stage 3) so a custom 12:1 piston built, a .600 lift cam with very radical valve events was ground and installed, a 42mm Edelbrock quicksilver carb installed and titanium valves machined and installed (1 15/16 dia. intake and 1 11/16 dia. exhaust) and revised squish area in head. everything was ground, lightened/polished & tweaked. Ran STRONG!!! Too strong--we found the weak link---transmission puked. we were running a custom built 17T counter shaft sprocket and 46T rear for a 5.39:1 ratio. I pulled 8500 in 5th for a calculated 122 mph. It blew the trans before we could really time it but the tach and gearing really dosen`t lie. Now, stage 4. De-tune, back to small cam, 10.0 compression etc. It was really too much for the transmission so we are happy with way less performance but reliability and more tractability. It STILL runs strong and still pulls 16/46 gearing to 8200 (in stage 3 we could get 10000 rpm in lower gears! Sounds SCARY at that rpm! ) We were very careful about balance and alignment and the engine revs extremely fast and is smooth over the rpm range. I`ve set an 8500 rpm limit on it and so far no problems.
There is a lot more to this story then I have here.
Hopefully I'll get some more to add in a few weeks...
Here is some info on other projects:
You asked about other projects. I`m building another tt yamaha for me with a big fin head (larger fins that the other one) and more downdraft but no offset (ala Manx Norton) and am going to run just a 38mm VM Mikuni and different cam, magneto etc. Have the frame modified for vertical installation of engine and a Falicon rod and all other parts so I just need time to put it together.
I first met Swede when I was selling parts out of my garage about 10 years ago.
He needed parts for a TT500 and I had a few laying around.
Here is what Swede started with:
Here is some engine work
Here is some of the end results:
Here's some words from Swede himself on the build:
I need to bring everything up to date. The bike is now in what we call stage 4 condition. First (original) bike had the engine in stock position in the frame with a mild cam and re-worked head i`ll send pics. of. Stage 2 the engine was installed in our modified frame to be vertical, not inclined per stock. This was so I could do a more radical head with more downdraft angle and more offset for better swirl and large valves and intake tract diameter (picture of engine you have is this configuration) and welding fins to head to increase cooling. A better cam was designed and ground and a 90mm sleeve installed in cylinder. Carillo rod and other items for reliability installed and a 38mm Mikuni flat slide installed. I also installed a Lucas competition magneto and a 41/2 lb flywheel along with a flat plate side cover/mag mount for better revving . A 10:1 Wiseco piston installed. Then we decided to see how far we could take it (stage 3) so a custom 12:1 piston built, a .600 lift cam with very radical valve events was ground and installed, a 42mm Edelbrock quicksilver carb installed and titanium valves machined and installed (1 15/16 dia. intake and 1 11/16 dia. exhaust) and revised squish area in head. everything was ground, lightened/polished & tweaked. Ran STRONG!!! Too strong--we found the weak link---transmission puked. we were running a custom built 17T counter shaft sprocket and 46T rear for a 5.39:1 ratio. I pulled 8500 in 5th for a calculated 122 mph. It blew the trans before we could really time it but the tach and gearing really dosen`t lie. Now, stage 4. De-tune, back to small cam, 10.0 compression etc. It was really too much for the transmission so we are happy with way less performance but reliability and more tractability. It STILL runs strong and still pulls 16/46 gearing to 8200 (in stage 3 we could get 10000 rpm in lower gears! Sounds SCARY at that rpm! ) We were very careful about balance and alignment and the engine revs extremely fast and is smooth over the rpm range. I`ve set an 8500 rpm limit on it and so far no problems.
There is a lot more to this story then I have here.
Hopefully I'll get some more to add in a few weeks...
Here is some info on other projects:
You asked about other projects. I`m building another tt yamaha for me with a big fin head (larger fins that the other one) and more downdraft but no offset (ala Manx Norton) and am going to run just a 38mm VM Mikuni and different cam, magneto etc. Have the frame modified for vertical installation of engine and a Falicon rod and all other parts so I just need time to put it together.