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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> 1998 Savage LS650 Engine knocking /cgi-bin/YaBB.pl?num=1221025889 Message started by Seattle_Savage on 09/09/08 at 22:51:26 |
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Title: 1998 Savage LS650 Engine knocking Post by Seattle_Savage on 09/09/08 at 22:51:26 My savage is running fine but the engine is knocking very loud, this is happening all time. I thought this came from the valves, so I did the valves adjustment and it did not help. So, I took it to motorcycle mechanic for him to look at the bike and see where the knocking coming from. What he was telling me that the sound come from when the piston hit the valves. So, question then if this is the case, then the valve should have been bench and the engine should have loose compression and the bike should stall by now, why it is still running fine? he was saying that it probably just touch the valve. So, there are 2 ways to fix this; 1. Install a thicker cylinder head gasket and this might increase the clearance between the valve and piston which eliminate this knocking sound. 2. take the piston out and file it down a bit on where the piston hit the valve (must be file on both sides for balancing). Does this seen logical to all of you and does any one have similiar problem like mine? Thanks, |
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Title: Re: 1998 Savage LS650 Engine knocking Post by YonuhAdisi on 09/09/08 at 23:28:45 It sounds like the mechanic is an idiot. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by KwakNut on 09/10/08 at 02:31:37 Does this mechanic work in a circus, wearing a lot of make-up, a curly red wig and long shoes? Because if you want to get quality advice like his again, I suggest you find another clown. The Savage has a low-compression flat top piston and a low-lift cam, so the valves get nowhere near the piston. Even if you had a sticking valve (which you can’t have if the motor is running okay apart from the noise), you would fix the problem not do what this eejut has recommended. Your noise could be one of several things. If it is really a knocking rather than a tapping, then it may be a bearing – big end or little end of the conrod, or bad piston slap if your bore is damaged and/or broken ring, but you’d get bad running if this were the case. If it’s a loud tapping rather than a knock, it could be a more common problem with the Savage, relating to the cam or cam chain. The cam chain adjuster is a common problem, or oil feed to the top end could have been bad at some time (due to low oil) and your cam may have eaten deep grooves into the followers (but if you’ve checked the valve adjustment and it wasn’t way out, it’s probably not this). If your engine is running okay apart from the noise, and it’s knocking, it’s a bearing. If it’s a more tinny tapping noise it could be cam/followers, if it’s more rattly it could be the cam tensioner has failed – but generally this would end up in the bike eating metal and not running. Might also be worth checking the decompression mechanism. I suggest you find another mechanic (don’t go back to this guy, because what he’s advised is beyond the realms of mere mortal incompetence – he’s up there with the demi-gods of buffoonery), and get a second opinion as to whether it’s a bearing knock or a top-end problem. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by savage2k on 09/10/08 at 06:24:37 Your mechanic's synopsis is preposterous. I agree with Kwak Nut and YonuhAdisi. Although it doesn't really sound like it, you might want to check is the engine mount bolts. I had a loose one and the vibration was unreal. Let us know when you solve the mystery. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by thumperclone on 09/10/08 at 06:34:20 are you "lugging" the engine,too high a gear too soon my 06 knocks a bit |
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Title: Re: 1998 Savage LS650 Engine knocking Post by verslagen1 on 09/10/08 at 07:38:34 Stock engine? How many miles? Take that mechanic off your referral list. Check the tightness of your bolts, sound can travel. And check to see where the sound might be coming from. The headlight and speedo are known rattlers, put a hand on them to eliminate them. Right side low, might be the cam chain. There's a tear down procedure in the tech section. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by Seattle_Savage on 09/10/08 at 11:59:58 Thanks for sharing. I did check all the bolt on the engine mount and they all okay. It is stock engine and it has 14,850 miles on it. I guess I will take ride this to Suzuki dealer and let them see what the problem is and give me a cost estimate. This will give me an idea of what is wrong with this bike. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by YonuhAdisi on 09/10/08 at 12:10:25 14,850? Then definitely check the cam chain tensioner. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by verslagen1 on 09/10/08 at 13:32:56 What ever they find, let us know. We'll let you know if they're full of it. And make them show you, don't except what they say. Take pictures. Measure how much the plunger is out. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by Seattle_Savage on 09/10/08 at 13:35:52 Let me look at the cam chain tensioner later today or tomorrow first and see there is problem there. Are you thinking that the chain is making the noise? |
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Title: Re: 1998 Savage LS650 Engine knocking Post by Seattle_Savage on 09/10/08 at 13:37:27 Oh, by the way I post the same question on the motorcycle forum and I received response that might be the piston hits the cylinder head. Is this posible? |
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Title: Re: 1998 Savage LS650 Engine knocking Post by justin_o_guy2 on 09/10/08 at 13:48:57 That can happen, but only once & that could only happen after the connecting rod ceased to fulfill its obligation in connecting piston to crank. In short, if its running, this aint happnin. Have you used a stethoscope/screwdriver with handle adainst bone at front of ear to generaly locate the area the sound is coming from? If not, you should. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by Seattle_Savage on 09/10/08 at 13:56:31 I don't know how to do that, but it is obvious the knocking/tapping come from the piston area. Since the piston move up and down so fast and the noise is louder when you increase the throttle. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by Seattle_Savage on 09/10/08 at 14:04:45 Anyone of you from Seattle area? I can take my bike to you so you can hear the sound ::) |
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Title: Re: 1998 Savage LS650 Engine knocking Post by Sandy Koocanusa on 09/10/08 at 19:20:10 I'd call that mechanic back in the morning. Tell him that you put more air in the tires. This raised the bike higher, lessening the pull of the Earth's gravity, thereby allowing the piston to travel more freely. Tell him the noise has gone away, but you appreciate his efforts and will send all your friends his way... as soon as they land in the mother ship. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by verslagen1 on 09/10/08 at 20:29:52 Have you have sparky out of its hole yet? and the end wasn't damaged? like you had dropped something down into the piston? My guess is you got a loose wrist pin, but the cam adjuster alot easier to check. anyway, I'd concider trailering it to the dealer. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by Seattle_Savage on 09/10/08 at 21:14:22 Sandy, that's a good one... I am taking this one to work tomorrow and let my other friend listen to it. He think it might have to do with cam chain tentioner. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by verslagen1 on 09/10/08 at 22:04:59 Let me answer this way... if it is, and it's clacking that bad, every time you start it, every revolution, you're rolling the dice... are you going to roll 7 or are you going to crap out... every turn of the engine... you need a 7. If you stop now and check it, you can stop rolling the dice. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by KwakNut on 09/11/08 at 00:44:59 546266546671666062070 wrote:
There is 3.5mm of clear space between the top if the piston and the cylinder head. Forget that line of enquiry - the guys on that forum must be smoking the same stuff as the mechanic you took the bike to. You're only going to get the piston hitting the cylinder head in one of two circumstances: A - Your conrod had let loose, and the inside of the motor is an expensive mess of hot oily chunks of useless metal. It wouldn't even turn over if the engine had blown like this. B - The engine has had a custom rebuild using aftermarket performance components and somebody got his math wrong. Unless the bike has just been rebuilt in this way, this is not the case. As for piston hitting the valves, B also applies. Piston/valve contact can also happen if a standard engine is assembled wrong with the timing chain out by a few teeth so the valves are opening at the wrong time, or if the chain has 'jumped' on its teeth (can happen on some motors). But, if this were the case, the bike would be very difficult to start and run like an asthmatic donkey. If it runs fine apart from the knocking, the cam chain is in the right place and the valves are NOT hitting the piston. If it's not just had some fancy but badly-planned rebuild, the piston simply CANNOT hit the cylinder head. Trust us here. 447276447661767072170 wrote:
Fingers crossed for you that if it's a bearing it's not the big end of the conrod - that would need a bottom end motor strip. Possibilities: Wrist pin Big end bearing (mains tend to rumble, not knock) Worn cam/followers Cam chain tensioner Broken piston ring (less likely) Decompression mechanism |
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Title: Re: 1998 Savage LS650 Engine knocking Post by Seattle_Savage on 09/11/08 at 07:26:34 Thanks KwakNut, Your info is very clear. I also cross my finger and hope it is not the bearing. I will update the forum once the problem is identified. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by T Mack 1 on 09/11/08 at 11:40:48 As others said, it would be a lot cheaper to open it up and look than to have it go bad. Going bad usually takes out parts that can normally be re-used. Also, if it goes bad and parts break apart, the engine should be torn apart and checked for metal fragments. That is very labor intensive and if you have to take it to a shop, would mean the bike is totalled…… . First and foremost, do a compression check on the engine. Next, what to open.... all these can be done in one day..... first, right side cover. Measure the cam chain tensioner (how far the rod is sticking out). You will need a gasket to put it back together. Also oil change is invoilved. Next, the Head cover (requires tank removal, but only uses gasket sealer, no gasket). Look at rockers and the cam lob surfaces. Also, if you can, look close at the cam journal (the surface the cam rides on). It's only aluminum and if the Prev Owner mistreated the bike (oil wise) it might have excessive wear. This manifests itself as a burr/bump of aluminum on it's edge by the chain sprocket. Will be hard to see. I'm not sure if that would make it knock since the cam chain is tight enough to stop it from bouncing (normally :-? ). If they are good, then the connecting rod would be suspect.... but it's very robust. If your oil is so bad as to take out the rod bearing, the cam journal would have been disintergrated long before. |
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Title: Re: 1998 Savage LS650 Engine knocking Post by justin_o_guy2 on 09/11/08 at 11:56:51 I would pop the right side off & check the cam chain before I ever started it again. No comp check, nothing. It is time & if it falls apart, it can be fatal. Eevn if the problem is found NOT to be the cam chain, it needs checked anyway. I would certainly start with a known problem instead of running the engine, hunting a relatively rare one, when running it could prove fatal. Of course, it it does blow up, I know where you can sell the right side cover.... Best O luck! |
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