Topic: I'm new and have a few questions (already)

[tunker2]

First of all, this looks like a great forum and I'm glad to be a part of it. I used to ride then got married and had a kid. I'm still married and still have a kid but just could not shake the itch to ride and recently purchased a 1976 CB550 in fairly decent shape. Been "passively" looking for a bike like this for probably 10+ years and this one was just too good to pass up. My goal is to slowly get it back original stock but with a slight cafe look (bars, mirrors, larger rear tire) hopefully still honoring it's original design. Here are my first questions...

1. The seat is original and in OK condition. However, there looks to be the start of a crack in the vinyl at the seam between the side of the seat and where it meets the top. It's about 2" long and will likely get worse the more I ride it (which is almost everyday). Any suggestions on a vinyl repair kit? There seems to be much out there to choose from.

2. Just ordered a MAC 4 into 1 exhaust system. These seem to be popular with Cafe bikes. Can anyone share thier experience? Sound? Performance?

3. Gas - what is the best octane to use on a bike like this?

4. Any suggestions for a "non-mechanic" to improve performance (horsepower)? The 550 is good but I live at 6,200 feet above sea level and combined with the hills around here, every bit helps!

That's all for now, thanks very much!

[kslrr]

The MAC's might solve issue #4.  At that higher elevation your bike could be running rich.  The new pipes, allowing the engine to breath better, might improve the air/fuel ratio.  If not much difference is noticed, you could try a less restrictive air filter (K&N) which fits in the stock air box as well.

Oh, and welcome!

[tunker2]

Thanks, just the answer I was looking for regarding performance. I will try a new air filter as well.

[mystic_1]

Welcome

You may be better off in the end looking for a replacement seat cover rather than trying to repair the existing one.  Even if you get the split closed up, other areas of the seat cover and stitching are just as old and will likely start opening up soon. 

mystic_1

[Chad]

Congrats on getting the bike you've been looking for.   

[SHORTROUND]

+1 on the seat cover.
+1 on the filter
Mac 4 into one great pipe for the money.

6200 feet above sea level rejet the carbs. if you can take out a screw and replace it you can rejet a carbs. they'll have a number stamped on them so you'll know what you have. if you're changing the exhaust and filter you may not need to but its likely thats its gonna be lean. but at 6200 ft that might be perfect. all other mods to increase horsepower involve cams, timing, and chamber/head work. i live in florida. so i'm pretty much at sea level so i can't tell you which jets you need. good luck. just remember that its better to have a vintage bike that runs good than a new one that runs great.

[TwoTired]

1. The seat is original and in OK condition. However, there looks to be the start of a crack in the vinyl at the seam between the side of the seat and where it meets the top. It's about 2" long and will likely get worse the more I ride it (which is almost everyday). Any suggestions on a vinyl repair kit? There seems to be much out there to choose from.

Once they start to crack it's over.  Patch the crack there will just make another pop somewhere else.  I battled this for a year.  Patch, new crack, patch, new crack, patch, etc., until the whole thing was patched, then it started cracking next to the patches,  Replaced the cover and then had time to work on other things.

2. Just ordered a MAC 4 into 1 exhaust system. These seem to be popular with Cafe bikes. Can anyone share thier experience? Sound? Performance?

I describe the Mac sound as "infectious".  They are louder than the stock 4 into 4 and sound better as the throttle is twisted farther and farther.  This makes the rider grin and the police frown, as the sound also makes the dial needles point the bigger numbers.  Personally, I like quiet power for the street.   Drawing attention from police officers is not in my best interest.  I sold the 550 with the Mac on it.  There only so much adrenaline you can make in a lifetime, and I don't want to run out of it too soon.

3. Gas - what is the best octane to use on a bike like this?

Regular, 87 pump rating.  It's got 9 to 1 compression ratio stock.  Higher octane is good for making oil company stock holders grin.

4. Any suggestions for a "non-mechanic" to improve performance (horsepower)? The 550 is good but I live at 6,200 feet above sea level and combined with the hills around here, every bit helps!

Check your spark plug tips for color of deposits.  If it's tuned correctly be happy with what you get.  Otherwise, it's a better cam and/or overbore (605 kit), with a freer exhaust and lower inlet restriction. Early 650 carbs are reported to help too.  Upping the C/R means upgrading the ignition.  How much do you want to spend for more HP?
Be aware, if it makes more power, it won't last as long, because all the stresses and wear increase.  Best to hop up a spare engine and swap back and forth as needed.

Cheers,