A great question. Before we get into that, I would call your attention to the location of the oil pressure sending unit and the fact that the upper end (cams, etc) are the last to get oil. That's why I'm so aghast at gonzo RPM starts. With that in mind, it's not too difficult to see that the light can go off (oil pressure good) long before the critical upper end parts get lube. Many years ago we would start a cold CB450 in the garage with no radio on and the door closed. At exactly 58 seconds after start-up, it would suddenly get very quiet. It took that long to oil the upper end ! Lets not speculate on any damage without a real pressure check first. I know that going anywhere near a dealer is like being condemned to hell, but suck it up and take this variable out of the equation. In the end you may have to remove the head cover just to examine the problem. Not yet.
--- On Sat, 3/14/09, tharrisn <[email protected]> wrote: From: tharrisn <[email protected]> Subject: [Nighthawk Lovers] Re: NOISE cont. To: "Nighthawk Motorcycle Lovers!" <[email protected]> Date: Saturday, March 14, 2009, 11:02 PM Would low oil pressure cause other noticeable problems besides the tappet noise? I know "idiot" lights on cars are notoriously bad at indicating problems but what about our bikes? I ask because the light comes on as it should when turning the ignition on but promptly goes off when the engine starts. On Mar 14, 2:06 pm, Dennis Hammerl <[email protected]> wrote: > This is starting to sound like an oil pressure leakback, caused by #1 thin oil (from heat) or that #2 the Sea Foam has loosened up some grunge that is unable to escape from that part of the system since a I described, is not open-ended. Now on the #1 cause, I'd get a dealer to check its real oil pressure when hot. There is a screw in gauge that dealers have to do this. > Shouldn't cost much to check. Low oil pressure can be many things. Don't panic. Since you didn't use anything on the second oil change we can't accuse anything of diluting the oil. > > --- On Sat, 3/14/09, tharrisn <[email protected]> wrote: > From: tharrisn <[email protected]> > Subject: [Nighthawk Lovers] Re: NOISE cont. > To: "Nighthawk Motorcycle Lovers!" <[email protected]> > Date: Saturday, March 14, 2009, 11:17 AM > > Doesn't sound like all the tappets are noisy but a few and not all the time. They are the loudest after the bike is hot and sets for ten minutes or so. I can almost guarantee when I start it back up and take off the noise will be very pronounced until it eventually quiets back down after a mile or two (quicker if I rev it a bit). They'll stay quiet until it idles for some time or I shut if off and start it again while still hot. I've changed oil and filter twice now in 800 miles. The first change I added SeaFoam (1/3 can). Second change straight engine oil (Shell 5W-40 Rotella-T). I'll make the next change using Marvel Mystery Oil. I've never used MM Oil before. How much can I safely put in the engine of this 83 650, or just follow directions on can? Will it hurt anything if I continue to "soup up" the engine oil at each change with MM Oil no matter how long it takes to stop the tappet noise? If I change oil at say 300 to 500 miles the next several > times do I need to change the oil filter too or can I skip to every other change while working on this problem? I'm going to give the engine every opportunity to purge it's little gremlins before taking more drastic measures like pulling the cylinder head cover. But, I'm collecting some spare parts should I need to dig deeper. You have helped a bunch! Thank you. On Mar 13, 10:42 pm, Dennis Hammerl <[email protected]> wrote: > I guess I stirred something up. I did check parts sites and found no new parts available. (that puzzles me, I never used any) They don't wear out and you can purge them. There is a tool for purging the air that you don't need, just makes it easier. Let's start here; do they (one or more) tap all the time, some of the time, once in awhile ? For the always and often cases, you may have to remove and purge. For the once in awhile, CHANGE OIL... then change it again. Get the nasties out. The 3K RPM deal is to force out the > particle. In practice, consider the adjuster like an oil pressure gauge. It's a dead-end that reacts to pressure. They do leak some out of the bore and back into circulation. I change my oil every thousand miles. Comes out like it went in. Seems a shame but the alternative would be more so. My one 700s started to tap on a trip and without any option, I continued to ride it home. It stopped some miles later and I changed the oil next day. > Never heard from again. Any top-end work and I remove them and place right-side up till I reinstall. Somebody once tipped over a few and I had to purge them before replacing in motor. If the problem persists and needs attention, the offending ones are easy to identify. To save time, use a screwdriver as a stethoscope and get a good idea of it's general location. There should be no clearance at any valve. Since they retain oil, the ones that are really hard to push down are good. Without oil, you are pushing against > a spring only. (still, a tough one) Now removing it is a chore. As I am want to do, I recommend to degree in the cams on any bike with high mileage if you have any reason to remove them. The results are well worth it. Bleeding the air out of an adjuster is a simple process where you insert an object into the hole in the end and while holding it under in a bowl of oil, work the piston till the bubbles stop coming out. Hold upright and install. > I once got a Hawk in that had been laying on it's side for a long time... uh oh. It started and rapped like mad for about 3~4 minutes. Once it quieted down, we changed oil and filter, sent it on it's way. You have to make the call as to what you want to do / can do for your problem. Everybody has thier own snake oil, I'm going to recommend Marvel Mystery Oil added to whatever you use. It's quite good at cleaning. One pint in my '86 700s does it for me. (that year has the largest sump) It is possible one could > fail, they are after all a mechanical device. That one would feel "not right" when purging. As in sticky, not smooth.Or a broken spring inside. > Any of this rambling help ? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. 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