Valve Adjustment? - Honda Rebel Forum
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post #1 of 11 Old 03-04-2014, 12:09 PM Thread Starter
 
Join Date: Sep 2012
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Valve Adjustment?

Hi All,
I'm getting the bike ready for Spring riding. I have 5500 miles on it, bought it with 2000 miles on it last year. Should I check the valves?
Seems to be running fine, I wasn't sure if it's truly needed. The honda manuals says to check them like every 4000 miles. Seems like a pain to do if I don't have to.
How long does it take you guys to check and adjust? Any noticable signs on when they need adjustment? Sounds like a sewing machine like usual. I know about the youtube video from zeprider. Thanks!

2008 Honda Rebel
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post #2 of 11 Old 03-04-2014, 12:34 PM
 
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It doesn't take long.. probably an hour or so. Maybe less once you've done it once.
Yes you should do it now, and no you don't wait for symptoms before you do it. By then the valve seats have started to burn and damage has been done. the idea is to keep the valve lash within spec at all times to avoid trouble.

It's pretty easy to do. You should remove the front tank mount bolts and loosen the rear mount so you can just lift the tank up a little at the front to get the valve cover off.
The valve cover is only secured by 2 special bolts and has a reusable rubber gasket.
Be real careful to seat the gasket again, and notice that the bolts have steel shoulders on them that seat directly on the camshaft mount below. Once they are finger tight tehy are metal to metal, and will not move significantly more. Just snug them up about half a flat turn of the bolt once they fetch. Lots of newbies have stripped the threads on these bolts which would be a major pain.



Once the valve cover is off you have access to the 4 valves for measuring clearance.
they should all be .003 measured with a feeler gage.

it's best to have a swingarm stand to get the rear wheel off the ground if possible, but not essential. You can use the rear wheel to roll the engine over to position the valves by putting the bike in 5th gear. Take the spark plugs out to make this easier, although this is not essential.

Roll the engine forward until you have one valve pushed all the way down. It's not necessary to be overly precise with this. As long as the valve is more or less pushed all the way down. Now you can measure the clearance of the corresponding valve on the other cylinder. Repeat for all 4 valves.
You will need proper wrenches to loosen the tappet locknuts and hold the tappet while you tighten the locknut again. If you need to adjust clearance, simply screw the tappet down on the feeler gage finger tight, and note its position. Hold the position with your tappet wrench while you tighten the lock nut. Use a torque wrench if you're not sure of the locknut tension. Check your clearance again by slipping the gage in and out of the gap. It should just slip in with a little pressure, not sloppy loose. It helps to bend the tip of the gage so you can lay it flat on the valve stem.

This method does not require removal of the crankcase plugs and alignment of the marks and is every bit as accurate.

2004 Rebel 250, 2003 BMW K1200GT (roadburner), 2004 BMW R1200GS(all purpose),
1973 Norton Interstate (in a box in the basement)
1968 Triumph Bonneville
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post #3 of 11 Old 03-04-2014, 02:30 PM
 
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https://www.youtube.com/watch?v=qZxB...e_gdata_player

04 Rebel 250 , 03 Magna 750, 98 Nighthawk 750
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post #4 of 11 Old 03-04-2014, 05:58 PM
 
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Quote:
Originally Posted by jsonder View Post
This fills in a lot more detail, which is good, but specifies removal of the tank and alignment of crankshaft marks, neither of which are necessary. A camshaft is perfectly round except for the valve lifting lobe, and on a 360 degree twin like the Rebel, when one cylinder's valve is fully open, the other cylinder's is in the middle of the round part of the cam where the clearance can be measured.

2004 Rebel 250, 2003 BMW K1200GT (roadburner), 2004 BMW R1200GS(all purpose),
1973 Norton Interstate (in a box in the basement)
1968 Triumph Bonneville
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post #5 of 11 Old 03-04-2014, 06:47 PM
 
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I found that removing the fuel tank provided more room for my inept hands to work, and better views of what I was doing.

I completely concur on the cam situation.

John '09CRF230L (L'il Red Piglet), '89NX250 (sold), '01Rebel (sold), '14CB500XA (given to son)
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post #6 of 11 Old 03-04-2014, 10:45 PM
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I have a 1985 with almost 9,000 miles on it. I purchased it with 7,500 and they had only adjusted the valves once, and that was at 3,500. The intake on both were spot on, and the exhaust were a little loose. From start to finish, an hour at most, and it's cheap insurance to know you personally know what they're at.

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post #7 of 11 Old 03-09-2014, 11:14 AM Thread Starter
 
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Thanks guys! I did the valve adjustment late yesterday. They didn't need any adjustment. I was surprised they were spot on, the bike has 5500 miles on it. Duckster I used the trick about switching it into 5th gear and using the wheel to rotate the flywheel, worked great. I need to get the rest of the bike back together today and make sure if fires up.

The only thing I noticed that I found odd was when the cylinder was at TDC both valves would always open. Is that correct? I always thought that only one valve was open at a time, never 2.

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post #8 of 11 Old 03-09-2014, 11:26 AM
 
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All the valves go through a complete open close cycle every 2 crankshaft revolutions. the left cylinder valves are exactly one crankshaft revolution apart from the right cylinder valves. Thus when left exhaust is full open, right exhaust is in the middle of its closed position on its cam.

I'm sure yours works just like all the rest.

2004 Rebel 250, 2003 BMW K1200GT (roadburner), 2004 BMW R1200GS(all purpose),
1973 Norton Interstate (in a box in the basement)
1968 Triumph Bonneville
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post #9 of 11 Old 03-09-2014, 05:59 PM Thread Starter
 
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Thanks guys. I finished putting the bike back together and it seems to be running fine. I don't hear any abnormal noises. Thanks for all the advice. Wouldn't have gone as smooth without everyones help.

2008 Honda Rebel
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post #10 of 11 Old Yesterday, 04:42 AM
 
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Personally I go with "If it ain't broke, don't fix it" logic. I have ridden rebels for years and never had a valve problem.

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2005 Honda Rebel 250
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