Compression test

[mack]

I saw a post that said to unplug the four pin connector from the TCI. Why?

[natemoen]

Prevent it from starting or even attempting to fire the coils.

[crazy steve]

It's to prevent the coils getting power, and if they're not connected to the plugs or grounded to the motor, you can damage the coils or the TCI....

With the pick-up coils disconnected, the TCI thinks the motor is 'off' and shuts itself down. I usually unplug the larger plug, that disconnects all power from the ignition.

[mack]

Thanks good to know

I,be never done that before but I'll start now. Checked the compression (cold) on Spica today and got 135,135,135,142.I'm pretty happy with that considering how long this bike sat. I'm sure they'll come up with some milage.

[DGXSER]

Since spec is 142 +/- 10%, And that was cold, I'd say your in fine shape as is!!

[mack]

Riding

Well she sure runs good. I've been out on her the last two days and it's amazing how smooth she is through the power band. Roads still have fine sand on them from the winter maintence making the grip tentative at best but I've managed to red line her twice in 4th(checking clutch adjustment), she rolls through the entire tach without any hesitation. Still doesn't have the snap of the SF, but still pretty impressive. This bike sat for almost 22 years after the original owner died suddenly. Two people had it after that but couldn't get it to run or ride properly. They only managed to put 200 miles on it, while in their possesion. Man am I glad. It looks and runs like they do coming off a show room floor.

[BA80]

Well she sure runs good. I've been out on her the last two days and it's amazing how smooth she is through the power band. Roads still have fine sand on them from the winter maintence making the grip tentative at best but I've managed to red line her twice in 4th(checking clutch adjustment), she rolls through the entire tach without any hesitation. Still doesn't have the snap of the SF, but still pretty impressive. This bike sat for almost 22 years after the original owner died suddenly. Two people had it after that but couldn't get it to run or ride properly. They only managed to put 200 miles on it, while in their possesion. Man am I glad. It looks and runs like they do coming off a show room floor.

That 81 won't ever have the snap of the 79. After 79 the compression went down, the cams got a lot milder and the carbs got the EPA workover too.

They tried to compensate for the changes with larger valves and it worked pretty well but it still won't have that thrill factor at 3.5-5K.

[mack]

For sure

i noticed that right away. The SF has a definate pucker factor you have to set up for when the mains kick in. This one is still strong but much smoother. Just doesn't have that turbo effect when you roll on the throttle. I still like it but, the SF is still my original and favourite of the two.