Ok, I'm with you on your explanation. I too think there is dirt or some other substance interfering with the hydraulic system related to the zero clearance adjusters. Maybe in a oil delivery passageway or probably more likely in the tiny hydraulic valve adjusters themselves. Is this sort of thing prevalent with bikes that have been sitting more than running?
Bit of history about this bike. I'm the second owner and have been able to chat extensively with the previous owner. With only 15k miles he obviously didn't ride it much and when he did was only around the block. Most of the miles were put on in the first few years of ownership. The previous owner also delivered with the bike old service records. A couple of those records indicated the original owner complained about a tapping noise 20 yrs ago. At that time the Honda service response was to rev it to 3,000 rpm 'till it goes away. Ok, that works kinda but I'm not satisfied. I'm more than willing to take a methodical approach to really fixing this thing. I plan to put a lot more miles on this bike than the previous owner did in 25 yrs and want to make sure I've done my best to help the bike deliver. So, I can verify the oil filter (Fram) is currently installed correctly, i.e. the spring and seat are present and on the "cover end" of the oil filter. The oil is fresh 5W-40 Shell Rotella-T and at the proper level. What next? Is it possible to remove each adjuster, clean and reinstall? I know you can't disassemble them but in your experience will flushing them with kerosene or some other solvent work? By the way, I purchased some used hydraulic adjusters from eBay in anticipation of swapping parts for test purposes. In my makeshift testing of the eBay adjusters they seemed to be fine. (I could not collapse them without unseating the check ball. Although, I know it's unlikely that I could physically exert as much pressure on them by hand as they'd see in an engine.) Much thanks for your help. On Mar 12, 11:19 pm, Dennis Hammerl <[email protected]> wrote: > I haven’t been responding to any of this chatter about > chatter because if you can’t tell the difference between a cam chain rattle > and > a valve tap, maybe riding the bus is more in order. I believe the noise > described > is a valve clearance tap. Cam chain noise is a rattle and is most pronounced > when a motor is near idle. Raising the engine speed a few hundred RPM and > letting it settle back to idle should reveal a loose cam chain. A valve > tensioner (they do not have hydraulic lifters) operates on oil pressure and > ensures that the valves run at a zero clearance. The noise that a collapsed > unit makes does not go away with higher RPM’s ,. They just get more obnoxious. > They do become suddenly quiet at times. Why ? It’s because whatever was > keeping > it from getting a supply of oil has become unstuck. Gee… Stick around, it’ll > be back. > > I will not describe the > construction or function of this device since readers don’t need or care to > know. Failure (collapse) is caused by lack of oil pressure. Lack of oil > pressure is caused by too low an oil level or a particle of dirt that reaches > it’s tiny orifice, starving it. What about this sudden increase of comment > makes this all the more interesting to me is that it references the CB650sc in > deference to any of the others. (Nobody > is mentioning the CB700/750sc or later model 750’s) > > I will assume the role of > Sherlock Holmes here and point out a difference between all these bikes. In > spite of the belief that they are related in construction, they most certainly > are not. Without going into the differences (and there are many) the one that > would account for this phenomenon is the oil filter. All the others use a > spin-on. Really hard to mess that up. As I have serviced more of these than > all > the members of this site own, I can relate a common flaw seen in many that > passed through our doors. An overwhelming number of these were found to be > missing the spring seat washer and / or the spacer in the filter housing. Add > to that a number that were assembled incorrectly. Now the 650sc is VERY > critical of it’s oil and it can’t be changed too often (this applies to all of > this family) A filter that doesn’t filter can’t be good. Low-grade filters > don’t help any. > > Usually some well-meaning > individual discards the old filter without examining it. The spring seat > washer > clings to the old filter and out it goes. Since you never saw it, you don’t > know it’s gone. The spring is there to hold the filter against the engine > block. The spring seat washer prevents the spring from creeping into the > filter > and allowing it to move away from the engine block. Once it’s no longer held > tightly, it ceases to filter. Enter the dirt. It will pass through and come to > rest somewhere. The hydraulic tensioners only operate with oil pressure, they > do not have a path for it to return to the sump. Once dirt settles there… tap, > tap. > > The finest grade of Llama > arm-pit oil goes to waste if the filter assembly is incorrect. > > A note to one respondent who > seems to have nothing good to say about these bikes; change brands… soon. > You’ll > sleep better. > > Anybody who wants to submit > MP3 files of his/her motor noises is welcome. > > 5D13 #1.jpg > 51KViewDownload > > 5D05 #1.jpg > 37KViewDownload --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en -~----------~----~----~----~------~----~------~--~---
