Topic: CB550 motor upgrade recommendations please

[HawaiiMike]

My '76 CB550F has a leaky head gasket.  I'm planning to take the motor apart, change the gasket and repaint the exterior parts with that aluminum colored paint to make it look new.

The speedo says 30k miles.  The motor VIN does not match the frame and title, therefore I don't know what the true mileage is on the motor.  When I rev the motor I see little or no black smoke.  It seems like the engine is okay.

While riding, the motor doesn't have a big amount of get up and go, it's alright though.  Not fast compared to a ZRX or Speed Triple but adequate. 

I've seen a lot of parts available on e-bay and other places.

Questions:
- Should I replace the head with a low mileage part?  I'd rather do that instead of valve job etc.
- Should I replace the cylinders and pistons?
- Cam chain?
- Primary drive chain?

Thanks!

[bwaller]

The engine #'s never match the frame. It may be impossible to know for sure but that may well be the original engine & mileage.

No they are not as fast as a ZRX but surely you expected that!

Maybe what you should do first is a compression test or leakdown. If you buy another head you may end up with something worse than what you have. It's not always necessary to spend a fortune on a valve job. If you are tearing it apart anyway, wait until you inspect everything before you decide. I would suggest changing chains, seals, and all gaskets automatically though while it's apart.

Make sure you secure a Honda shop manual and good luck.

[TwoTired]

My '76 CB550F has a leaky head gasket. 

I'll bet it doesn't.  Did you prove that with a compression test?  If it's an oil weep at the ends of the cylinder block, it's just the o ring for oil passage to the cam and tappets that's hardened and weeping.  My 74 has been doing that for 15 or 20 years.  Runs too good to rip if apart just for that.  I just wipe if off once a week, month, or when I feel like it.  Doesn't annoy me enough to spend $100 on a gasket set.

I'm planning to take the motor apart, change the gasket and repaint the exterior parts with that aluminum colored paint to make it look new.

Be sure to read up an cam cover install to avoid bending valve.

The speedo says 30k miles.  The motor VIN does not match the frame and title, therefore I don't know what the true mileage is on the motor.  When I rev the motor I see little or no black smoke.  It seems like the engine is okay.

It probably is OK and the one that came with the bike.  Engine numbers don't match frame numbers as routine.  If you post your frame and engine number, I can look it up to see if they're correct for the year model.  Somewhere on this site has number listings, too.

While riding, the motor doesn't have a big amount of get up and go, it's alright though.  Not fast compared to a ZRX or Speed Triple but adequate.

The 550 should do quarter mile in the 14s.

Questions:
- Should I replace the head with a low mileage part?  I'd rather do that instead of valve job etc.

You got money to burn?  What makes you think you need a valve job?

- Should I replace the cylinders and pistons?

Why?  If it's not burning oil and has good power you'll be replacing good parts with good parts.  Does the compression test point to a problem?

- Cam chain?
- Primary drive chain?

If you are hell bent to take it apart, then yes.  Are you ready to spend $500 or more on the engine alone?

Cheers,

[DarkRider]

Heres a link from one of my own topics that went into length as what can be done with the CB550 engine..

http://forums.sohc4.net/index.php?topic=27827.0

[Soos]

If you are looking to hop up your 550.... why not just drop in a 650 motor in your frame?


l8r

[HawaiiMike]

Here's the VIN: CB550F-2004021
Engine #: CB550E-1113812

In response to the other questions/comments-

I plan to take the motor apart regardless.  Either somebody did a poor job of painting the motor or the original paint is fading.  I want to change the gaskets and repaint it using this paint http://www.jeffscycles.com/Jeff_EnginePaint.asp . If you have a better idea about motor paints, please let me know.

If the motor has 30k miles on it, is it time for new rings?

I haven't run a compression test, please recommend a compression tester and where to buy it.

I am not planning to do a valve job.  I figure it's cheaper to buy a low-mileage head on e-bay instead.

A 650 motor would be hard to find in Hawaii.  And shipping from the mainland to here is brutal for something that heavy.

Thanks!
Mike

[TwoTired]

Here's the VIN: CB550F-2004021
Engine #: CB550E-1113812

Engine numbers are in the proper range for the frame serial number.

Most likely original engine for the bike.

[bryanj]

30K IS a low mileage engine.
Doubt you need rings
Change valve stem seals; camchain; primary chain; tensioner maybe; seals and gaskets

[ieism]

How many miles did you put on it yourself? I remember when I first had my 550, it was slow as well. After I rode it hard for a few hundred miles it realy woke up.

It will never be a fast bike like a modern one, but it should feel like it pulls strong troughout the revrange without dips at least.

[Hush]

Wheel it into a bike shop and get it professionally tuned and ask for a compression test.
If your carbs are out of whack it won't run the best.
In the long run this would be cheaper than hit and miss engine part swapping and at least you will know if it is running right.
Good luck with ya bike.............Hush.

[Gordon]

Wheel it into a bike shop and get it professionally tuned and ask for a compression test.
If your carbs are out of whack it won't run the best.
In the long run this would be cheaper than hit and miss engine part swapping and at least you will know if it is running right.
Good luck with ya bike.............Hush.

What?!  Take it to a shop to get a tune-up?  Hell no! 

Not only will it cost way too much, but you'll have no idea if it was done right, and you'll learn absolutely nothing about your bike. 

[HawaiiMike]

Hey thanks for all the helpful info.  I am looking around for a compression tester to buy.

I've only put a few hundred miles on the Honda.  I bought it last November and we had about a month of rain.

Just wrapped up a 60 mile ride today.  The bike has decent power, some rattling noises (maybe the license plate is vibrating on its mount) and the chain is kind of noisy too.  It looks okay, I'll put some lubricant on it just in case.

The old owner gave me his receipts.  The carbs were cleaned and synched back in 2002.  I think the mileage between then and now is just a couple thousand miles.  It also has a dyna ignition, that should simplify the home tune up big time.

Aloha, Mike

[ieism]

When you lube the chain, put the bike on the centerstand and let the wheel spin in first gear. Check if the chain runs smooth, and make sure it doesn't jump or makes clicking noises.
I had a chain break on me on the highway last week, you don't want that to happen.

And I would replace oil, oilfilter and airfilter, check timing and tappets.

[gene03079]

Sear's has a compression tester with hose extensions. This will work on the 550 for the #2&3 cylinders.

Good luck