Topic: 1971 CB500K Project:

[Greggo]

Well...after replacing the doubled up copper gaskets (PO job) with those silver/felt ones I've had nothing but trouble.  So, I ordered some copper Vesrah gaskets from ebay to see if that helps.  I'm also going to readjust the exhaust valves on 3 and 4.  I'm getting oil at all the tappets, so I'm confident I'm not having oil flow issues.  I'll readjust those tappets before swapping in new gaskets so I can get a feel for the individual adjustment's effects.  I'm really hoping I don't have a burnt valve  

Maybe it's time to start rebuilding the spare motor...

[Greggo]

Domer suggested I re check a few of the exhaust valves, so I did that.  Clearance on #4 was real loose, about a third of a twist on the adjuster screw.  Fired her up, and I don't think I hear the severe ticking anymore, but I thought I've had it fixed before, so I'm holding my breath until a test ride later today.

[Greggo]

A test ride revealed that the sound is still there, but now MUCH quieter after adjusting #4.  I only gave #3 a quick check, and no adjusting, so maybe that one's still a little off as well.  I haven't got much experience adjusting valves, but I think I will go back and re do all of them now.

<EDIT>  Just wanted to clarify that I know these bikes make some ticking noise.  This however, was significant, but now is mostly gone.  I'm also smelling a little burning oil, and getting a bit of gray/whiteish smoke after warming up for a minute.  The bike is still making good power.

[Greggo]

Adjusted all the valves: Intake on #1 let a .10 slide through, so the gap was at least double.  Intake on #2 was just about as loose.  Intake and exhaust on #4 were loose only by a thousandth each.  #3 was spot on, as well as the exhaust on #2. 

Test ride after the valve adjustments, and all systems are go.  No more 'exhaust leak' tick tick tickity.  Top end is broken in with the 650 cam, and the bike feels amazing.  There is definitely more power in the usable range, and the exhaust note is a little bit sweeter than before the 'exhaust leak' started.  And, I feel much more confident in caring for the bike now that I've adjusted the valves on my own for the first time. 

[Greggo]

Swapped out the rusty horn for a nice shiny one.  Had to swap the mounting brackets too, because someone bent the nice one's 90 degrees...

Before..


After..

[Greggo]

Took the bike on the freeway for the first time since swapping the cam...WOW.  I took this bike on the Rally down to Santa Cruz and back, and at 70, with headwinds, the bike had no balls whatsoever.  Now...incredibly responsive at that speed.  Very happy with the long term results, and I'd recommend the swap to anyone with a 500 or 550.

The shiny horn I put on there a few weeks back is garbage, way quieter than the rusty one I replaced.  Any way to refurbish these horns?   

[RAFster122s]

Did you try screwing in the adjstment screw while providing power & ground to the horn?  Maybe you're fighting a bad ground.

[Greggo]

Did you try screwing in the adjstment screw while providing power & ground to the horn?  Maybe you're fighting a bad ground.

There's an adjustment screw on the horn?? 

[mroberts5]

Any difference between putting that 650 cam in the 500 vs a 550?  Forum is loaded w/ 550 info, but short on references to swapping one into the 500.

[RAFster122s]

Pretty much the same operation ....may need a stronger clutch.

[Greggo]

Any difference between putting that 650 cam in the 500 vs a 550?  Forum is loaded w/ 550 info, but short on references to swapping one into the 500.

It is indeed the same operation.  Aside piston/cylinder size, the 550/500 top ends are virtually identical.  It is installed in the same manner as the shop manual instructs for re-installing a stock camshaft.  The notch on the 650 cam is in the same spot as the 500/550 cam.

Pretty much the same operation ....may need a stronger clutch.

Mine feels very solid still.  Though, it was replaced (w/stock) less than 2k miles ago. 

[Greggo]

I think my time has come...I need to clean the carbs - Boohoo, right?

I went for a good run today, and experienced something I got a hint of while crossing the Bay Bridge (scary enough as it is) - running at about 60mph at a steady pace, I feel at least one cylinder begin to cut out just slightly.  If I give it extra throttle, the missing cylinder comes back.  I'm only getting the problem at 50-60+, with a steady throttle (think cruise control).  I had plenty of good (Chevron, IMO) gas, lowest grade, and a few cap fulls of sea foam in every tank.  My riding behavior has changed since I've moved out of San Francisco; I ride at higher speeds more frequently, and am starting to notice the problem.  Should I be thinking carburetors? timing (Dyna S)? fuel flow to the carbs? coils (80's CB??? ~3.4ohms)?  The carburetors haven't been fully cleaned in over a year; although I do ride year round, at least every week or two, but usually much more often (daily).

[Greggo]

I think my time has come...I need to clean the carbs - Boohoo, right?

I went for a good run today, and experienced something I got a hint of while crossing the Bay Bridge (scary enough as it is) - running at about 60mph at a steady pace, I feel at least one cylinder begin to cut out just slightly.  If I give it extra throttle, the missing cylinder comes back.  I'm only getting the problem at 50-60+, with a steady throttle (think cruise control).  I had plenty of good (Chevron, IMO) gas, lowest grade, and a few cap fulls of sea foam in every tank.  My riding behavior has changed since I've moved out of San Francisco; I ride at higher speeds more frequently, and am starting to notice the problem.  Should I be thinking carburetors? timing (Dyna S)? fuel flow to the carbs? coils (80's CB??? ~3.4ohms)?  The carburetors haven't been fully cleaned in over a year; although I do ride year round, at least every week or two, but usually much more often (daily).

Ran half a can of sea foam and I'm good.  No more hesitation.  I think this bike hated San Francisco...too much stop and go traffic and slow speeds.  The East Bay has straight-aways, twisties, and open space where I can open her up

[Greggo]

Put new pipes on.  MC Enterprise 4-2 I picked up on ebay a few years ago.  The fit isn't perfect, but it sure looks better than my craptastic 4-1 I had on there.  Still need to tweak a couple pipes to get them completely settled in.  Sounds nice, just quieter.





Here you can see where it kind of interferes with the kick stand.  I need to put some kind of pad on the pipe it will rest on.  I also need a new mount stop for my center stand.


Like I said, not a perfect fit.

[Greggo]

Didn't like how the 4-2 fit, or sounded, so I pulled it.  I also installed some nice NOS Red Wings a buddy from work gave to me.  They were sprung really stiff for his 400F, so he stashed them away in his garage for ten years.  He found them while cleaning up shop, and thought I might be able to use them.  They lowered the back end about an inch, which makes the bike much more comfortable for my 5'7 self.  They don't feel too soft either, despite the negative comments I've heard on this forum about Red Wings.  So far, I like 'em.

[RAFster122s]

You selling the 4-2 exhaust? I might be interested...it looks very nice.

David

[Greggo]

You selling the 4-2 exhaust? I might be interested...it looks very nice.

David

Put it on ebay last week, and it sold in twenty minutes.  Even when I got it to fit correctly, it still didn't fit that well.  I'm trading away the 4-1 I have on the bike now, and I'm going to fit my Hooker 4-1, or my Yoshi pipe from Chris.

[Old75_ratafe]

Hey Greggo did I read that right did you say you were using the "lowest grade" cheveron?  That might be some of your issues right there.  I'm no expert on the 550's but the 750's are premium only.  I know even if my gas is like a month old it looses a little umph and I run 93 octane usually.

[Greggo]

Hey Greggo did I read that right did you say you were using the "lowest grade" cheveron?  That might be some of your issues right there.  I'm no expert on the 550's but the 750's are premium only.  I know even if my gas is like a month old it looses a little umph and I run 93 octane usually.

There is a school of thought that the lowest grade in today's standard is equal to the highest grade fuel of the 70's.  Unless your engine is modified (higher CR etc.) the higher grade fuels of today can lead to carbon build up in the combustion chamber.




I actually believe the problem is linked to the coils, specifically the side that's been firing my #1 cylinder, which continuously fouls out every month or so. 

[RAFster122s]

Did you try screwing in the adjstment screw while providing power & ground to the horn?  Maybe you're fighting a bad ground.

There's an adjustment screw on the horn?? 

Sorry I forgot to reply to your question.  Pop the chrome cover off and at about 9 -10 o'clock you'll find a screw.  Turn this a couple turns either direction while you've jumpered power directly to the horn.
 You can swap covers to a working horn.  Let me know how it turns out.

[Greggo]

Put the Yoshi replica pipe from MotoGPwerks on the bike finally.  It's incredibly loud, and gravely.  I love it, but my neighbors will hate me!  The #4 pipe fits a little wonky, and is leaking just a bit.  I don't think it's anything an extra copper gasket won't fix.  It was expensive, but once I fix it, I'll be very happy with it.  But, I did have to remove the center stand 

Here's some pics






This bike will more than likely get the Lesters I picked up too.  Not sure if I want to paint them silver, like the member formerly known as Traveler did.  The plan is for a black tank too.  Really not happy with the red.

[tweakin]

Looking good.  I have heard multiple stories about this pipes fitment being a bit off.  Can you change the oil filter without removing the pipe?

[Greggo]

Looking good.  I have heard multiple stories about this pipes fitment being a bit off.  Can you change the oil filter without removing the pipe?

Nope.  I have a filter adapter plate for spin on filters, but the filters that fit are too big to be taken off in that space.  It was really close.  So, I stuck with the stock housing, and I'll put the spin on onto my 750.  I did change the oil right before installing the new pipe.

Re the pipe fitment issues, this is my replacement pipe from Chris, and he was not happy to swap it.  This one fits twice as well as the first one did.  I really think a meatier gasket will resolve the issue.

[bwaller]

This guy Chris seems to be anything but happy to please. 

[Greggo]

This guy Chris seems to be anything but happy to please. 

Yeah, but I don't want my build thread to get deleted  It IS a really nice pipe once I get it settled.