hello, i am new to gs500's (motorcycles) and its my first time taking apart a motor. A few questions i ran into while working on mine.
1- can i check shim clearance with the head removed and the camshafts are not tightened by the cam holders? or do i need to torque the cam journal holders first?
2- if not, do the camshafts need to be on tdc when measuring the clearance with the head removed? because without tightening the cam holders the left exhaust lobe hits the shim and elevates the cam?
3- my gs is the 1991 year, do they make 17,18t front chain sprockets and 36,37 rear sprockets for this year? are the sprockets from the newer gs500's interchangeable with the old ones?
4- anyone know the maximum size air jet i can use with the gs500 carburetors on stock jetting?
5- Here are some pictures for fun of the valves when i removed the head, whats your diagnoses?
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#1 & #2: To check valves you need to have everything assembled properly, with only the valve cover removed.
#3: Yes they do make them, but choose either front or back, both and you might be pushing it pretty hard...and I'm willing to try just about anything! Make sure front one is the FLAT style without the stepped hub.
#4: Why would you want to change it?
Quote from: MongMan on June 05, 2013, 07:19:55 PM
1- can i check shim clearance with the head removed and the camshafts are not tightened by the cam holders? or do i need to torque the cam journal holders first?
You will need to torque the cam caps first
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2- if not, do the camshafts need to be on tdc when measuring the clearance with the head removed? because without tightening the cam holders the left exhaust lobe hits the shim and elevates the cam?
The cams do need to be turned correctly. See http://www.familyjones.org/paul/valve_adj.pdf for a sketch.
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3- my gs is the 1991 year, do they make 17,18t front chain sprockets and 36,37 rear sprockets for this year? are the sprockets from the newer gs500's interchangeable with the old ones?
The newer front sprocket will not fit the older output shaft unless you grind off the thicker hub.
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4- anyone know the maximum size air jet i can use with the gs500 carburetors on stock jetting?
Huh? :dunno_white:
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5- Here are some pictures for fun of the valves when i removed the head, whats your diagnoses?
Look Ok to me.
thanks for your answers!
another question hehe, when torquing the cam caps, at rtdc the left exhaust cam lobe sits on the shim elevating the cam, is it ok to torque it down and compress it on the shim/valve?
Best to rotate the engine a little to relieve the stress as you tighten it down.
Rotate clockwise with 19mm wrench on the timing rotor on the right side if the engine is assembled.
ok camshaft shim / washer / spacer, whats the deal with those? my manual wont say much on them. What is the recommended spacing or play between the camshaft edge and the head.
# 10 and # 3 in the parts fiche (camshaft - valve page)
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i happen to have 2 sets of camshafts and only 1 set of cam washers/shims. One of the camshaft sets with washers installed fit in the head, and the other cam set doesn't fit in the head if the washer are installed.
Those wavy washers are to quiet the camshaft endplay that is common in the older motors. What is the year of the head you are putting on?
Oh, and there is no spec on the spacing.
I dont know what year they are from unfortunately, when i bought the bike the seller gave them to me. Is it ok to not use those washers?