Topic: Advice for a friend looking to buy a CB 550

[flyin_]

I went with a friend to look at a 1974 CB550.  He asked for my help but I don't know too much about the 550.  I know a little about the 750s and thats about it.  The guy selling it is a coworker of his but he does not know the guy too well but its unlikely he would try and screw him.  Here are the details as I know them:

1974 CB 550 with 17K miles.  Looks very clean, paint etc.  It has aftermarket 4 into 2s that look really nice.  He just had it in to the shop for a tune up...carbs, valves, points etc.  The tires are like new and the chain and sprockets looked good.  It started right up cold and ran good.  I took it for a spin and it drove really nice but after I got back I though I noticed it bogging down a little when I was taking off.  I couldn't tell if it was normal or possibly not running really well once it got warmed up.  Also, when I got back from riding it the idle was up around 1500 rpm so I brought it down to around 1000.  After that the oil light started to blink on and off but would go away once the rpms got above about 1200.  I checked the oil and it was clean and up to the right level. It actually might have been a little high. 

So the guy was asking around $1000 for the bike.  I would like any opinions as to what you guys think of the oil light and possible bogging down and the price.  I don't know what the 550s are worth or what problems there might be with those issues. 

Thanks for the help.  It would be fun to have another friend out riding an old CB

[Gordon]

If I was looking for a running 550 and this one came up, I'd say it's missing the stock pipes, needs carb work, and probably a new oil pump, and offer him $700.  If he counter-offered $800, I'd take it.  But that's just me, and only if the paint is stock, in good condition, and with stock side covers. 

The problems you mentioned could be very easy and cheap to fix, or they might not, but there's no reason to let the seller know that. 

[eldar]

OK granted, I have a 750 but my oil light does not come on when the engine runs period! No matter how low the rpms get.
pump is probably tired. I am with gordon. I might even start at 600.

[Bob Wessner]

Also, when I got back from riding it the idle was up around 1500 rpm so I brought it down to around 1000.  After that the oil light started to blink on and off but would go away once the rpms got above about 1200.  I checked the oil and it was clean and up to the right level. It actually might have been a little high.

What weight oil was he using? Did it smell like there might be fuel mixed in? Just looking for other alternatives as to why this light is blinking short of a tired pump, which really shouldn't be I wouldn't think if there are only 17K on the bike.

[GroovieGhoulie]

Also, when I got back from riding it the idle was up around 1500 rpm so I brought it down to around 1000.  After that the oil light started to blink on and off but would go away once the rpms got above about 1200.  I checked the oil and it was clean and up to the right level. It actually might have been a little high.

What weight oil was he using? Did it smell like there might be fuel mixed in? Just looking for other alternatives as to why this light is blinking short of a tired pump, which really shouldn't be I wouldn't think if there are only 17K on the bike.

Agreed.  17K and these things are just getting broken in.

Replacing the exhausts with factory pipes will cost around 600 bucks, so bear that in mind.

[Jeff]

FWIW, I just paid $600 for a 77 550K with 17600 miles, runs pretty good but could use carb cleaning and a crap 4 into 1 Mac exhaust. Paint is alright, side covers are original. Seat is near perfect. I'm in MN, if that means anything. No oil light problems, although I have some oil weeping at the gasket. Ignition switch just crapped on me as well, so I had to replace that too.

I feel like I got a good deal. Not a great deal, but a good one.
Jeff

[csendker]

I got my '75 550 last year for $350.  It needed a battery, new front brake pads and air in the tires.  I think I got a really good deal, but then lots of stuff is cheap here in Buffalo with our backwater politics choking the life out of the region, but I digress. 

My oil pressure light had a one-time problem after running for an extended period at high RPM and a hot day.  The longer I went, the higher I had to hold the RPM's up to keep it off.  A simple oil change and new filter seems to have cured that problem.  I've seen the sending units up for sale occasionally, maybe just a bad sensor?  Too high a level is no good, and the wrong viscosity is also a no-no.

[flyin_]

Thanks for the input guys.  Keep the comments coming
I think the paint and emblems are all stock and are in good condition.  My friend likes the exhaust so that is not an issue. 
So is sounds like $1000 is a bit too high.  Maybe an offer of $600 to $700 might be a good price to pay. 
Does anyone know what would be needed if there were a problem with the oil pressure?  Would this just an oil pump issue or could there be other internal problems?  I just have a hard time believing that one of these bikes could have serious problems with only 17K miles even if it was possibly abused. 

[csendker]

Besides the speedo on the bike, I own two or three other gauge sets and can change the odo reading at will, not to imply that anyone is screwing with the milage mind you.  I had a blown shifter seal that I fixed, only to find it was covering up a slight weep in the oil pump casing.  Not enough to impact the pressure delivery, but a bad leak may.  Good oil, a new filter, and the proper level will all impact this.  The repalcement exhaust will breath a bit easier than the original 4-1's, but probably not enough for rejetting. 

[flyin_]

So if this was possibly an issue with the oil should it clear up right after an oil change?  Maybe we could change the oil in it and run it before making an offer to see what happens. 

[csendker]

A floating idle is typically indicitave of crudded up idle jets.  A good thorough cleaning should fix that.  A Yammy carb treatment or Seafoam may do it also.  The bogging down could just be the set-up; carbs, exhaust, air filter, jetting.  Maybe do a plug chop to see if it's running lean or rich? 

My problem was fixed with a simple oil change, but then maybe I was just lucky.  A gunked up intake screen may be a problem too.  You can drop the oil pan and see what it looks like - the pan has an o-ring gasket that can be re-used.  Another thought: If the bike historically ran with dino oil, and then was switched to synthetic, the detergents go to work and start to clean everything up.  Unfortunately, some of the cleaned-up gunk may start to block the proper flow of oil throughout the engine.

[ElCheapo]

My guess is that it has car oil in it. ONCE AND FOR ALL.. CAR OIL IS NOT SUITABLE FOR WET CLUTCH BIKES.

If it had 20/50 of Belray in it the light dance might go away. I say give him $700 MAX and run like hell if it is complete. Then motors can come cheap if needed in the future.

[RyanLilly]

Elcheapo, I am New to these bikes, An you Define "Car Oil" My manual on the 750 calls for 10w-40 or 20w-50, Is there a difference between this same weight for car and for bikes? Or are you saying that it has oil that is too thin? I would just like to further my own understanding.
Thanks,
-Ryan

[Jeff]

A car clutch is not lubricated by the engine oil, but a bike clutch is. There are detergents or something in car oil that you do not want to use in a bike because of the clutch. On the back of the oil bottle it will say something like SF or SJ as well as some other ratings. Bike oil has different ratings than a car, but I can't remember which is which. Short version... don't use car oil in your bike.

Jeff

[dusterdude]

My guess is that it has car oil in it. ONCE AND FOR ALL.. CAR OIL IS NOT SUITABLE FOR WET CLUTCH BIKES.

If it had 20/50 of Belray in it the light dance might go away. I say give him $700 MAX and run like hell if it is complete. Then motors can come cheap if needed in the future.

tom,relax brother,dont have a stroke  .btw,i run castrol 10w40 dino in mine with NO problems at all.

[Klark Kent]

GTX?

[GroovieGhoulie]

GTX?

Yep.  that's what I use to no ill effects.  Due to the extreme summer heat, I'm running 20w-50, but I usually run Castrol 10w-40