1976 CB550F "Barn Find"

what master are you looking for? I have one off my cb360 (same as factory 550) if you need it? has GP levers on it, I even have a clutch perch and GP lever for that too
 
Re: 1976 CB550F "Barn Find"

MiniatureNinja said:
what master are you looking for? I have one off my cb360 (same as factory 550) if you need it? has GP levers on it, I even have a clutch perch and GP lever for that too
A 14mm for 7/8 bars, is it in good condition?
 
Re: 1976 CB550F "Barn Find"

snmavridis said:
A 14mm for 7/8 bars, is it in good condition?

it's in great condition (cap is that faded purpleish anodized black color) but I am not using it due to doing a remote master cylinder setup on my bike
 
Re: 1976 CB550F "Barn Find"

MiniatureNinja said:
it's in great condition (cap is that faded purpleish anodized black color) but I am not using it due to doing a remote master cylinder setup on my bike
Pm me some pics!
 
Re: 1976 CB550F "Barn Find"

Weekend update: bought an AGM Duracell battery (sick of dealing with flooded batteries), changed the oil, dropped some oil in the spark plugs holes, tested compression off the kick start just to see where we're at, mounted my wiring harness, plugged her in, pushed the starter button and got her to chooch! Not ready to do the full startup yet, I think I crossed some wires as my coils continue to get juice even when I switch the kill switch to 'off'!

As for compression: I tested it with no fuel in the carbs, throttle closed (don't have the throttle cables hooked up and didn't think to open the slides), pods on, kicked 5 times over with the kick starter. Attached are my readings. ~120psi on each cylinder. Probably going to retest with WOT and the push button start next weekend.

All in all, I think she'll be running by the end of the month. The weather is getting nice, and my friends are all riding without me. I got the bug, guys.
 

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That 120 with closed throttle is pretty good. there seems to be less than 5 psi difference between highest and lowest so that's good too. Should be at around 150 with the throttles open cold, so will be higher again on a warm engine.
 
Maritime said:
That 120 with closed throttle is pretty good. there seems to be less than 5 psi difference between highest and lowest so that's good too. Should be at around 150 with the throttles open cold, so will be higher again on a warm engine.

What Maritime said ^^^ also, I've seen these engines run relatively fine even at 100psi somehow....not ideal, but it did run :) You are so close! Keep at it!!
 
Re: 1976 CB550F "Barn Find"

So I bought a fender eliminator from DTT user zookmoto and I'm damn glad I did. This thing is awesome. Really complements the bike!!! If you're thinking about buying one, just pull the trigger. Worth it.

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Re: 1976 CB550F "Barn Find"

Fuck. Tappet cover snapped. Fuck. Do I need to get a new tappet cover before I start this up? Or can it be started without a tappet cover? Also, do I need to check for debris now?

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If you start it with that tappet cover missing it's gonna spray oil everywhere. I would doubt there is much, if any, debris from it. You'll have to get the remains of the broken one out of the threads. Luckily those things are a dime a dozen. Honda used them on like a dozen engines.
 
Re: 1976 CB550F "Barn Find"

Well here we are. Electrical system is complete. Getting spark to all four plugs. Just add gas and shes good, yes? Nope. I had her choochin for a while and she gave up the ghost. Anyone know why I'm backfiring out of the intake? Also seems to be a leak in the carbs. Goddammit. Suggestions? (Video below)

https://youtu.be/RwPBf_F89KU

On the plus side, got me a points cover and new tappet covers.

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Re: 1976 CB550F "Barn Find"

The backfiring could be a timing issue. Or a stuck valve. Did you make sure all the valves were free and moving?


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Re: 1976 CB550F "Barn Find"

john83 said:
The backfiring could be a timing issue. Or a stuck valve. Did you make sure all the valves were free and moving?


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Without taking apart the engine, how do I check if they're stuck? She turns over freely, which bodes well, no?

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did you check the valve clearances? a slightly over tight clearance, especially on an intake valve can cause a lot of grief. That being said you had consistant compression on all 4 cylinders so not likely to have had a stuck valve then, but once you got it warm, if there was one or 2 valve clearances too tight it will then allow a valve to stick open a little and ruin compression. you can check your valves from the tappet covers with a feeler gauge but don't adjust them unless the engine is cold. like sat overnight cold. If you can't get a feeler gauge of any size under the valve at TDC compression stoke, that's a problem and you can fix it after the motor is cold.
 
Re: 1976 CB550F "Barn Find"

Maritime said:
did you check the valve clearances? a slightly over tight clearance, especially on an intake valve can cause a lot of grief. That being said you had consistant compression on all 4 cylinders so not likely to have had a stuck valve then, but once you got it warm, if there was one or 2 valve clearances too tight it will then allow a valve to stick open a little and ruin compression. you can check your valves from the tappet covers with a feeler gauge but don't adjust them unless the engine is cold. like sat overnight cold. If you can't get a feeler gauge of any size under the valve at TDC compression stoke, that's a problem and you can fix it after the motor is cold.
Will do. I just checked my timing with the points... I don't know what happened, but they're off. By alot. Im going to readjust them and try to fire her up after I check valve clearances again. Also, the bottom of my tank looks "creamy". It's a smooth even cream color. Is that normal? Almost looks like a liner maybe? I don't want to put gas in it and risk mucking up the engine. In the meantime I have a syringe hanging from the ceiling with fuelline attached to the carbs through a tee. Maybe I'm starving it of fuel too? But when I put the gas in, it seems to overflow the carbs and they start leaking. Fix one problem and 100 more show up.

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Re: 1976 CB550F "Barn Find"

snmavridis said:
Will do. I just checked my timing with the points... I don't know what happened, but they're off. By alot. Im going to readjust them and try to fire her up after I check valve clearances again. Also, the bottom of my tank looks "creamy". It's a smooth even cream color. Is that normal? Almost looks like a liner maybe? I don't want to put gas in it and risk mucking up the engine. In the meantime I have a syringe hanging from the ceiling with fuelline attached to the carbs through a tee. Maybe I'm starving it of fuel too? But when I put the gas in, it seems to overflow the carbs and they start leaking. Fix one problem and 100 more show up.

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that's usually a symptom of a worn float needle/seat allowing the carbs to overflow like that.
 
Re: 1976 CB550F "Barn Find"

MiniatureNinja said:
that's usually a symptom of a worn float needle/seat allowing the carbs to overflow like that.
Roger that. Let's see if the timing helps get it started and if not, I'm diving into the carbs again.
 
Re: 1976 CB550F "Barn Find"

Seems my light pops on when it shouldn't. At f2-3 there is power going to p1-4. Then it stays lit until after I pass the f1-4 mark. Any thoughts? I've tried swiveling the base plate, but nothing changes.
 

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