Valve adjustment help

tondi · 08-26-2018, 02:05 PM

Hi everybody, I'm new to this forum and I really need your help

Yesterday, I made a valve adjust as per service manual (0.002" intake & 0.004" Out). I did follow all the steps on the manual: TDC mark aligned, engine cold and spark plug out, but, the result was a total disaster, my valves are noisier that ever and I'm totally sure I will brake them if I drive like that.

I'm trying to understand what was wrong and my best guess is that I calibrate the valves at the wrong position even if the TDC mark was aligned. There and some clues to try to understand the problem:

1- When I opened the engine, the actual valve adjustment was negative, I mean, there was no gap at all and the valve screw was pushing down the valve. I had to unscrew the valve a lot ( like 3/16") in order start having a gap between the spring and the screw.

2- I could not remove the generator cover cap (Seems to be weld) so I put the motorcycle in 5 gear and I pushed back until the mark was aligned. Was this wrong ? The T mark was perfectly aligned with the crankshaft line and the valves were on top.

3- The valves were on the top position when I calibrate them, Is this how is supposed to be ? I moved the wheel after calibration and I realized that the gap increased when the valves where down, this is pretty weird, I thought that the maximum gap was the one I used as per manual. It is possible that my T mark is not quite in the right place ????

Thank you so much for your time

bachelorb · 09-05-2018, 11:11 AM

Could you be 180 degrees out? Looking at the service manual, it says piston needs to be TDC on the compression stroke. Now...... This is just from memory and fixing lawn mowers, and I don't even know if it applies here, but it may be worth a shot (....and someone please correct me if I'm way off). TDC on the compression stroke is when the Piston is up at the top of the cylinder, and no valves are moving. I usually use a dowel to find top dead center. I stick it in the spark plug hole and feel when the piston gets to the top (be very careful to keep it loose in there and don't let it jam). When the piston is near the top, none of the valves should be moving. If they are, then you are not on the compression stroke. Move the crank another round and get the piston to the top and the valves not moving..... then line up the timing marks......

If it is 180 out, and you start it.... serious things can and will happen (experience is a bitch........)

I hope others will add to this. Like I said this is not specifically for motorcycles, but what I've been doing in general for years.

Hopefully I'll be adjusting the valves on my new motor later today and will have more to add. Thank you for bringing this up though because I am now going to make sure the piston is TDC on compression.

Brad

edited to add- Yes, this is the case. I first turned the flywheel to tdc and the intake valves were moving. Once more around and everything was as it should be. Make sure you are at TDC in compression

suzukix668 · 10-06-2018, 07:38 PM

Its easer to do the valves with a metric feeler gauge the intake is .05 to .06 MM
the ex is .09 to .11MM after each valve adj you must rotate the engine than ck the valves again after each adjustment one valve at a time

Donald McPherson · 10-07-2018, 03:48 AM

You can also feel the compression stroke when you pot your thumb ofer the plug hole when you rotate the engine. As you Americans have twin cylinders would you not need to do one at a time then rotate the engine one turn to do the other side?

alantf · 10-08-2018, 04:35 AM

Twin cylinders? no. Twin valves? Yes.

08-26-2018, 02:05 PM	#1
tondi Junior Member Join Date: Aug 2018 Location: Montreal Posts: 14	Valve adjustment help Hi everybody, I'm new to this forum and I really need your help Yesterday, I made a valve adjust as per service manual (0.002" intake & 0.004" Out). I did follow all the steps on the manual: TDC mark aligned, engine cold and spark plug out, but, the result was a total disaster, my valves are noisier that ever and I'm totally sure I will brake them if I drive like that. I'm trying to understand what was wrong and my best guess is that I calibrate the valves at the wrong position even if the TDC mark was aligned. There and some clues to try to understand the problem: 1- When I opened the engine, the actual valve adjustment was negative, I mean, there was no gap at all and the valve screw was pushing down the valve. I had to unscrew the valve a lot ( like 3/16") in order start having a gap between the spring and the screw. 2- I could not remove the generator cover cap (Seems to be weld) so I put the motorcycle in 5 gear and I pushed back until the mark was aligned. Was this wrong ? The T mark was perfectly aligned with the crankshaft line and the valves were on top. 3- The valves were on the top position when I calibrate them, Is this how is supposed to be ? I moved the wheel after calibration and I realized that the gap increased when the valves where down, this is pretty weird, I thought that the maximum gap was the one I used as per manual. It is possible that my T mark is not quite in the right place ???? Thank you so much for your time Login or Register to Remove Ads
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09-05-2018, 11:11 AM	#2
bachelorb Member Join Date: Aug 2018 Location: Chelsea Ok Posts: 46	Could you be 180 degrees out? Looking at the service manual, it says piston needs to be TDC on the compression stroke. Now...... This is just from memory and fixing lawn mowers, and I don't even know if it applies here, but it may be worth a shot (....and someone please correct me if I'm way off). TDC on the compression stroke is when the Piston is up at the top of the cylinder, and no valves are moving. I usually use a dowel to find top dead center. I stick it in the spark plug hole and feel when the piston gets to the top (be very careful to keep it loose in there and don't let it jam). When the piston is near the top, none of the valves should be moving. If they are, then you are not on the compression stroke. Move the crank another round and get the piston to the top and the valves not moving..... then line up the timing marks...... If it is 180 out, and you start it.... serious things can and will happen (experience is a bitch........) I hope others will add to this. Like I said this is not specifically for motorcycles, but what I've been doing in general for years. Hopefully I'll be adjusting the valves on my new motor later today and will have more to add. Thank you for bringing this up though because I am now going to make sure the piston is TDC on compression. Brad edited to add- Yes, this is the case. I first turned the flywheel to tdc and the intake valves were moving. Once more around and everything was as it should be. Make sure you are at TDC in compression __________________ Brad Bachelor "Marrying an old bachelor is like buying second-hand furniture." - Helen Rowland Last edited by bachelorb; 09-05-2018 at 02:31 PM.
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10-06-2018, 07:38 PM	#3
suzukix668 Junior Member Join Date: Nov 2010 Location: la ca Posts: 23	Its easer to do the valves with a metric feeler gauge the intake is .05 to .06 MM the ex is .09 to .11MM after each valve adj you must rotate the engine than ck the valves again after each adjustment one valve at a time Login or Register to Remove Ads
	0

10-07-2018, 03:48 AM	#4
Donald McPherson Member Join Date: Aug 2018 Location: Aberdeen Scotland Posts: 47	You can also feel the compression stroke when you pot your thumb ofer the plug hole when you rotate the engine. As you Americans have twin cylinders would you not need to do one at a time then rotate the engine one turn to do the other side? Last edited by Donald McPherson; 10-07-2018 at 03:51 AM.
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10-08-2018, 04:35 AM	#5
alantf Senior Member Join Date: Nov 2008 Location: Tenerife (Spain) Posts: 3,715	Twin cylinders? no. Twin valves? Yes. __________________ By birth an Englishman, by the grace of God a Yorkshireman. Login or Register to Remove Ads
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