Topic: cylinder not firing and weird ticking/clicking sound

[Brady]

not yet. planning to. figure i should clean first.

[Brady]

Hey Phil71,

regarding the oil issue you referred to originally, is there some kind of way to verify that being a problem?

[XLerate]

I didn't see any mention of how many miles on this engine or bike, or its general condition? Is it thrashed or well taken care of? Pretty hard to diagnose anything long distance not knowing if it has 25K miles or 100K miles, also the total mileage has an effect on possible suspects at the scene of the crime.

[Brady]

bike has 31k on it but tach was broken when i got it a couple months ago so who knows how much it was ridden after it broke....don't know much history on bike, guy i bought from got in a package deal and only had it a few weeks...i know it sat for at least a year prior most likely outside. who knows how long before that. maybe somewhere in between thrashed and neglected?

[phil71]

Are you talking about worn tensioners? Those actually don't look too terrible in those pics. Oil pressure is a different story. If you hold the cam chain with something smooth and spin the motor over you ought to see loads of oil spitting out of the galleries. If you don't .. change that pump.
  The cam in the photos looks to have some uneven wear, but no obvious catastrophes. How do cam follower part of the rocker arms look?

[Brady]

what to do. what to do.

@phil71  cam followers have wear but they're smooth. don't seem out of wack in anyway.  also, have received some conflicting info regarding oil spurting from the sides.. was told on later models(mine is 77) that it will only seep out the sides not gush like earlier models.



So I removed all the valves and started cleaning up the head and all that. there was a crapload of carbon on the valves and seats.  def not helping things.  Valves mostly seem ok but a couple are possibly ever so slightly bowed. it's kind of hard to tell. my eyes may be playing tricks on me. I did have one that was a little sticky coming out of the guide. So i'm thinking I will just go ahead and replace the valves unless someone here tells me otherwise.  there doesn't seem to be any slop in the guides(i.e. the valves don't move around side to side except for a tiny bit in just one guide) so thinking i dont need to do those as well. nor do i want to as it seems like a pain in the ass and $$$$.  am i ok putting in new valves without getting new guides. hoping noise is just from a valve not seating. a lot of ppl have suggested i have an exhaust leak...seems to be the most common suggestion anyway. i dunno.

Also noticed yesterday that the dowel pin on the side of #1 cylinder was clogged up w/ rusty gunk and the base of it was slightly corroded so i'm sure oil probably wasn't flowing as good as it could and there's a lot of sludge in the oil pan. engine does not seem to have been treated well. def didn't get an oil change for a while it seems. also some very minuscule metal flecks in the oil pan which makes me want to open the bottom end and inspect to see if there's something overly worn down there.

Pistons show some wear but I'm not sure what's considered normal for a bike w/ 30k miles on it. #4 is the only one w/ wear that seems concerning possibly(see pics below). I'd be up for getting some new pistons but i don't really want to do it until i figure out what's causing the noise. Cylinders seem pretty good to me...i'd like to get by w/ a hone and new rings and maybe new pistons if i need it.


Other than that I'm trying to decide how far to go w/ the rebuild. I don't want to throw too much into it until I know I've fixed what's making this crazy noise. Ideally if i could replace gaskets, piston rings, cam chain, valves and valve stem seals then throw it back together and see if that solves anything that'd be great.


here's a question though, if I have to reopen this thing up after replacing the head gasket is that going to kill my gasket again b/c the old one was stuck to the casing and my thought is the new one would just get #$%*ed up again from removing the head after the new one is installed.



I ran across a parts bike for $300 and wondering if i shouldn't pick this thing up and see if the engine wasn't treated a bit better but then that's a whole other gamble.


Here's some pics

Pistons:








Cylinders:




Oil Pan:



Metal shavings the magnet picked up out of the oil pan:

[Vinhead1957]

Not liking piston 4 for sure !   You might get away with honing and a new piston, but you are there why not all four ??

[Brady]

hey vinhead, yeah i would def do all 4 at once if i went for new pistons.

[Brady]

Thought I'd share an update.  cracked the cases completely today after noticing that the connecting rod for piston #4 had a ton of free play in it.  opened 'er up and voila...crankshaft bearings on #4 shot to #$%*.  which explains the wear on #4 and presumably the noise i was getting....  but! why the wear on the bearings is the next question?

PS. you don't need to go through the pain of removing the rotor to split cases on a 77 cb550 in case anyone is wondering... read a lot of threads about how much of a PIA that was to get off.