junununu Posted October 19, 2010 Posted October 19, 2010 Alright, the one last thing bugging me with my bike before I can accept her as she is: sorry for the extremely terrible video but I'll do my best to narrate: It sounds like an air leak coming from near the carb boots. I can hear the chirp up to about 3800 RPM and then after that the engine noise either blocks it out or it doesn't happen. When I accelerate the rate of the chirping goes up with the RPM. I've been googling and the closest sound I found was a CB550 with a blown head gasket. I also noticed a bit of oil bubbling from the spark plug socket, which I thought was the original culprit. I drained some of the excess oil to within the levels, and the bubbling of oil has stopped but the sound has not. Thanks for all the help, its hard to get work done during the day worrying about my baby.
Moderator drewpy Posted October 19, 2010 Moderator Posted October 19, 2010 try locating the noise with a screwdriver touching the engine and the handle in the ear. doesn't sound good, like a dry bearing! is the oil light lit then goes out when started? have you got enough oil in the engine? measured when the dipstick is resting on top of the threads!! could also be the end camshaft advance mechanism, might just need to strip and oil!
junununu Posted October 19, 2010 Author Posted October 19, 2010 (edited) is the oil light lit then goes out when started? uh, so this isn't the normal behavior? I just picked up a new filter, and will be swapping that out when I get home, replacing the oil. Hopefully that fixes something. EDIT: I can only hear this from the left side, from the right side, the engine sounds muffle the chirping. A lot of searching leads me to the camshaft chain tensioner making the noise, but the cam chain is in the middle of the two cams, so it doesn't make sense for the noise to be only heard from one side. Edited October 19, 2010 by junununu
junununu Posted October 19, 2010 Author Posted October 19, 2010 could also be the end camshaft advance mechanism, might just need to strip and oil! which part of the haynes manual should i be looking at for this?
Moderator drewpy Posted October 19, 2010 Moderator Posted October 19, 2010 which part of the haynes manual should i be looking at for this? its on the bike mate, not in a book ignition, its behind that finned cover top of engine, you only need the haynes to do the timming!
junununu Posted October 19, 2010 Author Posted October 19, 2010 its on the bike mate, not in a book ignition, its behind that finned cover top of engine, you only need the haynes to do the timming! I'll start my research. This is my first mechanical engine I'm working with, so I'm a bit slowww. So is it behind the 'points cover'? "The mechanical ignition advancer is on the other end of the camshaft under the chrome right hand head side cover. The points cam lobe and advancer are connected by a governor rod that goes through needle bearings in the center of the camshaft." where is the chrome right hand head side cover? the noise is coming from the left side!!!
Moderator drewpy Posted October 19, 2010 Moderator Posted October 19, 2010 "The mechanical ignition advancer is on the other end of the camshaft under the chrome right hand head side cover. The points cam lobe and advancer are connected by a governor rod that goes through needle bearings in the center of the camshaft." where is the chrome right hand head side cover? the noise is coming from the left side!!! are you sure you have an xs400 manual? no needle bearings in the top end, the cam runs directly in the head! no govenor rod (whatever that is) don't forget this is a sohc model not the later dohc the advance mech is the second picture! is that the actual picture of your bike?
Moderator drewpy Posted October 19, 2010 Moderator Posted October 19, 2010 found your problem, it was under your tank
junununu Posted October 19, 2010 Author Posted October 19, 2010 are you sure you have an xs400 manual? no needle bearings in the top end, the cam runs directly in the head! no govenor rod (whatever that is) don't forget this is a sohc model not the later dohc the advance mech is the second picture! is that the actual picture of your bike? i actually got these pictures from an xs650 site, but i know the points cover looks very similar to that. the governing rod is probably a reference to the electrical ignition modification they were doing. So in the advance mech in the second picture, what should i be lubing?
Moderator drewpy Posted October 19, 2010 Moderator Posted October 19, 2010 i actually got these pictures from an xs650 site, but i know the points cover looks very similar to that. the governing rod is probably a reference to the electrical ignition modification they were doing. So in the advance mech in the second picture, what should i be lubing? why are you showing video of a car and a different bike? your totally throwing me off just undo the freeking points cover, take off the contacts plate, undo the 10mm bolt on the end of the camshaft. lube up the pivots and check for rubbing. replace and retime/set the points.
junununu Posted October 19, 2010 Author Posted October 19, 2010 why are you showing video of a car and a different bike? your totally throwing me off just undo the freeking points cover, take off the contacts plate, undo the 10mm bolt on the end of the camshaft. lube up the pivots and check for rubbing. replace and retime/set the points. Sorry, just wanted to provide a clearer video with a better sound for it. I'll try this when I get home and report back. thanks!
junununu Posted October 19, 2010 Author Posted October 19, 2010 Update: I get home and one of the screws that holds the points cover is stripped, whoopee. On another note, after leaving it be for 48 hours, and letting the oil drain out overnight, and a fresh oil filter and new oil later, the sound disappeared, only for a few seconds. and then a few seconds later, the sound continued the oil light came on, and poof the oil filter had somehow come loose, and the oil leaked out. I resealed the oil filter, put in new oil, started her up, and got the same squeaking sound, with no oil problems this time around. I'm almost certain that the sound is coming from behind the points cover now, but wondering if the few seconds of normal operation after draining the oil might be a symptom. Also: how dangerous would it be to ride around with the sound assuming it doesn't get any worse and it really was the advance mechanism causing the noise? I have limited time before and after work to get to places and no car.
bznchris Posted October 20, 2010 Posted October 20, 2010 Per a Clymer manual: "Compression leaks at the head-cylinder joint will sound like a rapid on and off squeal." Sure sounded like a 'rapid on and off squeal' to me!
junununu Posted October 21, 2010 Author Posted October 21, 2010 just undo the freeking points cover, take off the contacts plate, undo the 10mm bolt on the end of the camshaft. lube up the pivots and check for rubbing. replace and retime/set the points. Upon removing the contacts plate and the ATU, there appears to be a small oil leak in the oil seal. I'm guessing the points and the end of the camshaft that rotates under it should be dry right? Could the leak in the oil seal cause smoke to come out of it during a rough start?
junununu Posted October 21, 2010 Author Posted October 21, 2010 From the Poster of the Video: I figured out the squeeking noise. It was a very very slight leak around the choke plunger body. Big enough to cause a noise, but not big enough to cause running problems. Tightened the screws a bit and noise was gone. of course its not for the same xs400 model, but could this be a similar problem?
Moderator drewpy Posted October 21, 2010 Moderator Posted October 21, 2010 Upon removing the contacts plate and the ATU, there appears to be a small oil leak in the oil seal. I'm guessing the points and the end of the camshaft that rotates under it should be dry right? Could the leak in the oil seal cause smoke to come out of it during a rough start? at least you know oil is getting to the camshaft that side! the seal does tend to leak a little bit, the smoke will be caused by a faulty valve seal which sits around the valve stem, they tend to go hard and leak. this will prevent a clean start up with the bike left standing, but clears after it runs a bit! points should be dry as they are electrical make sure the advance mechanism is lubed up so the bob weights can move freely
junununu Posted October 21, 2010 Author Posted October 21, 2010 at least you know oil is getting to the camshaft that side! the seal does tend to leak a little bit, the smoke will be caused by a faulty valve seal which sits around the valve stem, they tend to go hard and leak. this will prevent a clean start up with the bike left standing, but clears after it runs a bit! points should be dry as they are electrical make sure the advance mechanism is lubed up so the bob weights can move freely Got that. All is lube and appear to be working. I got a great lesson in contact points when i didn't understand what 'fully open meant' and adjusted the plate when the engine wasn't turned over fully. I got mediocre power with full choke but realized that something was definitely wrong. Adjusted points properly, and will start but still that damned bird squeal. I can only think of the cam or the intake manifold at this point. looks like the right side manifold was repaired, and the left side has a fairly large crack that I'm not sure runs all the way through. I will order new manifolds but in the meantime try and seal it with rubber cement and see if it goes away...
Naebdyret Posted July 19, 2011 Posted July 19, 2011 I realize its a bit late for a reply, but one way of ensuring the carb holders arent cracked all the way through is to spray ether on to them while the engine is running while making sure the ether doesent reach the intakes on the airfilters. If the engine RPM rises when spraying ether on the boot, the carb holder is leaky - if it doesent, its all right.
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