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I am fairly new to riding and motorcycles in general, and have learned that my "shade tree" mechanics knowledge is fairly useless with my '80 XS 100 G. I have an engine noise that almost sounds like a knocking rod, but I think it is not loud enough. A couple of people have told me it sounds like my timing is off, but I am unsure on how to check that. Any help?
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In comparison to other engines these have a lot of top end noise from the valve train. I would suggest just doing a valve shim check and adjust it necessary before trying to adjust timing. Could also check the cam chain tension.Nathan
KD9ARL
μολὼν λαβέ
1978 XS1100E
K&N Filter
#45 pilot Jet, #137.5 Main Jet
OEM Exhaust
ATK Fork Brace
LED Dash lights
Ammeter, Oil Pressure, Oil Temp, and Volt Meters
Green Monster Coils
SS Brake Lines
Vision 550 Auto Tensioner
In any moment of decision the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing.
Theodore Roosevelt -
Timing Show-N-Tell...
Here's a video of the timing being checked/set:
http://www.youtube.com/user/ThreeFaz.../2/-CgQ3Uf_7WU
Courtesy of Member/Guru here 3Phase.Comment
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+1 on camchain tension. Check that first - supposed to be done every 1k miles, and the engine will be a lot noisier on top with an improperly adjusted chain. My $.02I think I have a loose screw behind the handlebars.
'79 XS11 Standard, Jardine 4/1, Dyna DC1-1 Coils, 145 mains, 45 pilots, plastic floats - 25.7mm, XV920 fuel valves, inline fuel filters, speed bleeders, Mikes XS pods, spade-type fuse block, fork brace, progressive fork springs/shocks, manual petcocks, 750 FD, Venture cam chain tensioner, SS brake linesComment
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an out of sync carb
can cause a knock,
wouldnt hurt to check to see if
the carbs are synced.
couldnt see that the timing would cause
a knock especially if its knocking at idle,
in saying that it still wouldnt hurt to check it.pete
new owner of
08 gen2 hayabusa
former owner
1981 xs1100 RH (aus) (5N5)
zrx carbs
18mm float height
145 main jets
38 pilots
slide needle shimmed .5mm washer
fitted with v/stax and uni pod filters
[url]http://www.youtube.com/watch?v=3pA8dwxmAVA&feature=mfu_in_order&list=UL[/url]Comment
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If the vacuum 'advance' hose is connected to a carb boot nipple instead of the nipple on carb #2 then it can cause the vac adv mechanism to "flutter" or bounce, causing a rattle or knock at low (idle) RPM.
Just another (easy to fix) possabilityPat Kelly
<p-lkelly@sbcglobal.net>
1978 XS1100E (The Force)
1980 XS1100LG (The Dark Side)
2007 Dodge Ram 2500 quad-cab long-bed (Wifes ride)
1999 Suburban (The Ship)
1994 Dodge Spirit (Son #1)
1968 F100 (Valentine)
"No one is totally useless. They can always be used as a bad example"Comment
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Flutters and Bouncing at Low Rpms...
Yup! And even when it is connected correctly it makes noises at low Rpms...Originally posted by Pat Kelly View Post
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Thanks
Thanks for all of the input and advice. Will definitely let you all know when I have it dialed in!Comment
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An exhaust leak can also sound like a knock from the top end.Ty
78 XS1100E - Now in Minnesota
80 XS1100LG - The Punisher
82 XJ1100 - Current project - The Twins
82 XJ1100 - Wife's Bike - The Twins
82 XJ1100 - Daughter's Bike
72 Suzuki TS125 - Daughter's Bike
72 Yamaha Mini JT2 - Youngest Daughter's bike (She wants a bigger one now)Comment
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Hve checked the cam chain tension, and the sound remains. Will check the valves next, but I feel nothing from putting my hand on the valve covers. Bike runs strong, but I have concerns.........Comment
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I also agree an out of sync carb will produce a knock sometimes, BTDT. Also you can try a thicker oil. I had a motor once that I had to run 70W in it to quiet the knock. Try 40W or 50W. JAT2H7 (79)
3H3
"If it ain't broke, modify it"
☮Comment
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How do I find intstructions on how to properly check and adjust valve shims??Comment
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Resources for the How-To Owner?
how 'bout this:
http://www.ringler.us/family/mybike.html
It's c-Bug's website where you can download the repair manuals which cover the step-by step of the valve clearances check/shim selection and....
everything else that you're gonna wish you have the repair manual for.
(Not a bad idea to skim through his musings bout his bike either. I thought it was a good read...)Comment
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