Valve Adjustment Issues on XS650?
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From: ? on 18 Jul 2010 16:09 On Jul 18, 12:01 pm, ERIC2008 <ericng...(a)gmail.com> wrote: > Thanks for the quick responses, but I've been following the > instructions from my haynes guide. Haynes manuals are *very* unreliable. They tell you how to take things apart and then say that "re-assembly is the reverse of the above." When I did a valve job on my Nissan pickup truck, the Haynes manual explained how to make a special wooden tool to support the cam chain, saying that the tool was "to keep the chain from falling off the bottom of the crankshaft sprocket." Actually, the purpose of the tool was to keep tension on the chain when the automatic chain tensioner tried to take up perceived slack in the chain when the camshaft sprocket was unbolted. Since there is no access to the cam chain tensioner without removing the water pump and front timing cover, I had to spent two extra days on the valve job...
From: Datesfat Chicks on 18 Jul 2010 18:12 "ERIC2008" <ericngsta(a)gmail.com> wrote in message news:ae997024-9247-43bc-8ef8-008d76f264f3(a)y12g2000prb.googlegroups.com... > > I've also been setting the valves in neutral, turning the engine > through the nut on the rotor, I feel like this isn't giving me the > most accurate TDC. Could this be the issue? How are you determining TDC exactly? Hopefully not looking at the piston? I'm assuming there are timing marks or TDC marks somewhere that you are using? There isn't an inherent issue with turning the crank manually. I think this is how its done. The issue is that if you are looking at the piston, basic geometry says that it will be hard to determine TDC exactly because there will be a wide angular range of crank position during which the piston will be at pretty much the same position. During this range of motion, I'm not sure what the camshaft will be doing relative to whatever rides on the cams. Shop manual? TDC marks? My Honda has a port that you open up and you can then see marks on the flywheel or similar part. There are two questions I'm not qualified to address: a)What the cam is doing near TDC, which I think would affect the way you adjust the valves. b)If your method for determining TDC could be responsible for the behavior you're seeing. Datesfat.
From: ERIC2008 on 18 Jul 2010 19:27 Hey Dates, I've been using the markings on the flywheel, however, while turning the nut on the rotor in neutral it seems to pass the TDC on its way down, I just realized that I should try it in gear to have a little more resistance. Again, I'm not sure if it would cause these symptoms. It sounds more like a stuck valve, but they look like they are all moving correctly. Would I be able to see the valve physically stuck or not moving when turning the engine?
From: Datesfat Chicks on 18 Jul 2010 20:08 "ERIC2008" <ericngsta(a)gmail.com> wrote in message news:2a843cc0-50f1-4252-aa61-81ab9b1e4c7e(a)u4g2000prn.googlegroups.com... > Hey Dates, > > I've been using the markings on the flywheel, however, while turning > the nut on the rotor in neutral it seems to pass the TDC on its way > down, I just realized that I should try it in gear to have a little > more resistance. Again, I'm not sure if it would cause these > symptoms. It sounds more like a stuck valve, but they look like they > are all moving correctly. Would I be able to see the valve physically > stuck or not moving when turning the engine? You'll have to wait for others who are qualified to answer the questions you posed above. I once tried to do my own valve adjustment. I stripped the hex hole on one of the access ports on the crankcase cover. I took it to the dealership and let them remedy it. I've never done a valve adjustment. I was just curious about how you were determining TDC and why you felt that your process was inaccurate. Since I've never actually done a valve adjustment, I have no insight about your difficulty in positioning the crankshaft or in guessing whether a valve is sticking. As long as you are using the correct timing mark (there is probably one for each cylinder) and getting it after the compression stroke rather than after the exhaust stroke, you should be good ... Datesfat
From: The Older Gentleman on 19 Jul 2010 11:28
ERIC2008 <ericngsta(a)gmail.com> wrote: > I've been using the markings on the flywheel, however, while turning > the nut on the rotor in neutral it seems to pass the TDC on its way > down, I just realized that I should try it in gear to have a little > more resistance. Again, I'm not sure if it would cause these > symptoms. It sounds more like a stuck valve, but they look like they > are all moving correctly. Would I be able to see the valve physically > stuck or not moving when turning the engine? <A dedicated XS650 nut writes> It does that. It has a tendency to sort of 'roll past' the timing mark. Valve spring pressure and/or compression, I guess. I've had other bikes do it as well. Take out the spark plugs and put it into gear, like you suggest. Nothing abnormal about it. -- BMW K1100LT Ducati 750SS Triumph Street Triple Honda CB400F Suzuki TS250 Suzuki GN250 chateaudotmurrayatidnetdotcom Nothing damages a machine more than an ignoramus with a manual, a can-do attitude and a set of cheap tools |