Topic: winter upgrades for cb500

[Hrvatski Medvjed]

It's getting cold in Minnesota and after riding in snow flurries and 28 degree temps a couple of days ago, I can't help but ponder my winter upgrades and the spring road trip I have planned with a couple of my riding buddies. Now then, I'm not looking to go crazy with mods (no big bores unless I open her up and there's a reason to do a lot of work) but I wouldn't mind getting a little more acceleration and a little more top end out of it.

Here's what I'm thinking:
Electronic Ignition - which one are you using and are you pleased?
650 or Aftermarket "hot street" cam and valve springs- recommendations?
Ported head work (if I can find a good shop near the twin cities to do it) - is it worth it?
CB750 carbs - is it worth it? Anyone have tips for this one?

Trying to gain a little bit while doing most of the work myself and hopefully not having to explain too many expenses to the boss :-)

1973 CB500 - Basically Stock and runs quite well.

Thoughts/Tips are greatly appreciated

[Tews19]

Get a running 650 engine..... 20 percent jump in HP I think...... only 2 lbs heavier then a stock 550 engine..... I know it is a direct bolt in swap for a 550 so I think may be the same for a 500 frame... If you can find a running engine, say for a few hundred. A 650 wire harness, with carbs... You can have it done in an afternoon....

[Hrvatski Medvjed]

Hmmm...hadn't considered that as an option, that might be fun if I can find something reasonable. Still like the idea of pepping up the 500 motor though...

[Tews19]

You can get complete running 650's for dirt cheap... Seen some go for as little as 350 bucks around here... In WI

[Bankerdanny]

Since you would be swapping into your 500 you don't need to be concerned about a title, which gives you lots of leverage when looking at a running 650.

As far as your current engine goes "runs quite well" translates to "leave the damn thing alone" to me.

If you want to do engine work, get a different engine ans swap it in when it is done. Then you don't run the risk of still having a non-running bike in the Spring when it is trip time. Because you know how pissed you will be if you don't get to ride because you decided to mess with a good running bike and couldn't finish it in time or just can't get the modified engine dialed in.

[Mo]

650 engine will drop in, but will require the mounting bracket (only one of them, the rest are the same. Forget which. I believe Scott has done this) from the 550. Also, as mentioned the wiring harness, clutch cables, carbs.

The 650 camshaft in a 500 is not worthwhile without the 650 pistons. (Domed in a 650 vs flat in a 500, giving it the desired compression ratio).

Electronic ignition won't give you power. I have it, and its advantage is I never have to mess with points. PAMCO makes a good unit.

[Tews19]

Why wouldn't a cam swap be helpful? It helps with mid range from what I have read... I have a 650 cam waiting on my 550 engine build for this reason... You do not need to swap out pistons or anything to notice a gain.... The cam will be fine.

[Tews19]

Not sure how close you are but here is a complete running 650... The yr in the listing is incorrect...

http://mankato.craigslist.org/mcy/4082504579.html

[Bailgang]

Why wouldn't a cam swap be helpful? It helps with mid range from what I have read... I have a 650 cam waiting on my 550 engine build for this reason... You do not need to swap out pistons or anything to notice a gain.... The cam will be fine.

I don't know what Mo is referring to but a 650 cam in my 550 really woke the engine up. I later on installed an adjustable cam sprocket so I could advance the valve timing 6 degrees which woke up the mid range even more, I lost a bit of top end power by advancing the timing although I actually never noticed it because it still pulled like a bear when it hit 7k rpm up to redline. I had also installed kibblewhite valve springs.

Installing a good 650 engine would definitely be more cost effective and "easier" but I've never been known to do things the easy way simply because I like the challenge. Back in the day when all my brothers and friends were racing either Fords or Chevy's I instead chose a Pontiac. 

[Mo]

I guess I might be wrong here, but I always read that because the pistons were different, you wouldn't get the full benefit. Maybe that was for a 550 and not a 500?

Anyways, I guess I have been corrected.

[Bailgang]

I guess I might be wrong here, but I always read that because the pistons were different, you wouldn't get the full benefit. Maybe that was for a 550 and not a 500?

Anyways, I guess I have been corrected.

Well I guess the OP was referring to installing it in a 500 not a 550 like I did so you might have a point.

[Hrvatski Medvjed]

I had always read that a 650 cam would swap in direct and increase mid range output...either way, I might go for the cam and valves springs, but, i'm fairly set on carbs and ignition - skip on the porting. This bike runs good so I don't want to ruin it!

[Bankerdanny]

The best way to not ruin a good running bike is to not mess with the engine. You can't mess it up if you leave it alone.

[Hrvatski Medvjed]

The best way to not ruin a good running bike is to not mess with the engine. You can't mess it up if you leave it alone.

Seems like fairly sound advice. Not always the most fun but, sound nonetheless.

[Bankerdanny]

I only point this out because you have mentioned on several occassions how well it runs.

A quick run through the threads here will turn up hundreds of threads about poor running bikes and many are because the owner decided to make just because.

I agree that building up an engine would be fun, but as I suggested before, find yourself a stand alone engine and built it. That way you can enjoy riding the bike while you do.