Honda CX 500 Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
Hey, Im brand new to the forum, so firstly, I'd like to say thanks for reading. The bike was fine, bit of a clunky engine sound, which i assumed was normal. I also kept hearing some 'popping' noises from the exhaust, a friend of mine recommended checking and adjusting the valve clearances. I followed this site:



http://www.pdsrecording.site90.com/cxgl500/CXGLTappets.htm#CXGLTappets



The tappets were supposed to be 0.1mm - the ones on my bike were set REALLY tight, there was NO gap for me to put the feeler gauge in. I double and triple checked EVERYTHING. Put it all back together, and fired her up. Just to point out a couple of things - I changed the tacho cable while I had the radiator off, but i couldnt remove the fan. I got the bolt of, but it wouldn't budge, it was completly solid, no wiggling or loose in any way. Also, because I couldnt get the front inspection cover off as PO rounded off, i actually used the fan to turn the engine to TDC - This probably wasnt the cleverest thing to do, but i assumed it did the same thing?



So, once i fired her up, i can hear a clunky sound. Its much worst than it was before and i cant tell if its from the fan or from the tappets. I decided that maybe I was just being paranoid, so i took her out for a ride. I was out for 15-20 minutes on a humid day in England (not exactly hot) and looked at the temp, and it was in the red.



So basically, i need to know these points:



  1. Was turning the engine via the camshaft (using the fan) a bad idea?
  2. Could I have done something wrong with the tappets or could they be worn?
  3. How do I take the fan OFF properly to inspect?
  4. What are the possible culprits for the noise?



On the other hand, the engine actually operated more responsively. My take on it is this:



The tappets were so tight, that the valves were not opening fully. This caused the bike to be sluggish. When I set them properly, they were letting in the right amount of fuel, causing it to get hotter and also making it more responsive, however my cooling system needs flushing.



Im starting to go crazy over this, so ANY help is very much appreciated.



Thank you so much for reading!
 

·
Registered
Joined
·
7,223 Posts
Welcome to the forum, you will find a lot of help here from some of the nicest and smartest people I have ever had the pleasure of gathering info from.



1 - Yea, because of the small amount of slack in the timing chain, it will throw off the valve clearances doing it that way. Use the 17mm bolt on the crank at the front (under a 17mm cap cover) to turn it to TDC. Also, there are TWO TDC rotations for the engine (one at compression and one at exhaust) you must make sure you have it on the right one. When yout TDC left (start with left) you should have a fractional amount of play on BOTH rocker arms (is not very much but you should be able to feel it). If only one is "slack" rotate the crank clockwise until the TDC L comes up again, then both should be slack.



2 - Yes and yes. The main problem is if you set the gap on the "exhaust stroke" it will really mess up the gaps and run really bad if it runs at all. You could also have excessive "slapping" of the lifters.



3 - I fought for weeks with that until this forum told me the proper EASY way. once the fan bolt is out, the inside of the fan has a thread (M14 1.5 pitch). By screwing a bolt in (at least 2" long) it will eventually hit the cam shaft. Tighten it a bit the tap the bolt head a few times with a hammer and tighten again. This will act as a puller and the fan (which is sitting on a tappered section of the cam and is basically a "press fit") will pop of very easily.



4 - Hard to say, if you can describe them the best you can, or even better, record it and post the sound file so others can hear it. from what you described it is probably the valve clearances that are possibly worse than they were before. Have to make sure your TDC on the Exhaust stroke)





Also, the above is dependent on your actual bike. If you update your profile with your location and bike make and year it makes helping a whole lot easier. The stuff I listed is basically the same for all CX500's, but some things are bike make/year specific. Also, knowing your location makes it easy incase one of the members lives around the corner from you and can meet you to help out
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #3 ·
Welcome to the forum, you will find a lot of help here from some of the nicest and smartest people I have ever had the pleasure of gathering info from.



1 - Yea, because of the small amount of slack in the timing chain, it will throw off the valve clearances doing it that way. Use the 17mm bolt on the crank at the front (under a 17mm cap cover) to turn it to TDC. Also, there are TWO TDC rotations for the engine (one at compression and one at exhaust) you must make sure you have it on the right one. When yout TDC left (start with left) you should have a fractional amount of play on BOTH rocker arms (is not very much but you should be able to feel it). If only one is "slack" rotate the crank clockwise until the TDC L comes up again, then both should be slack.



2 - Yes and yes. The main problem is if you set the gap on the "exhaust stroke" it will really mess up the gaps and run really bad if it runs at all. You could also have excessive "slapping" of the lifters.



3 - I fought for weeks with that until this forum told me the proper EASY way. once the fan bolt is out, the inside of the fan has a thread (M14 1.5 pitch). By screwing a bolt in (at least 2" long) it will eventually hit the cam shaft. Tighten it a bit the tap the bolt head a few times with a hammer and tighten again. This will act as a puller and the fan (which is sitting on a tappered section of the cam and is basically a "press fit") will pop of very easily.



4 - Hard to say, if you can describe them the best you can, or even better, record it and post the sound file so others can hear it. from what you described it is probably the valve clearances that are possibly worse than they were before. Have to make sure your TDC on the Exhaust stroke)





Also, the above is dependent on your actual bike. If you update your profile with your location and bike make and year it makes helping a whole lot easier. The stuff I listed is basically the same for all CX500's, but some things are bike make/year specific. Also, knowing your location makes it easy incase one of the members lives around the corner from you and can meet you to help out


Thanks for the help! Right, okay, so I basically did the valves completely wrong by using the fan. Okay, ill pop to the nearest hardware shop to grab one of those M14 x 1.5 bolts to get the fan off. (I plan to do the electric conversion). So the noise could be the 'slapping' of the tappets because the engine wasnt at TDC? What If i cant get the bolt off for the inspection cover to turn the engine over? Right, thanks for the info, I will go back to the garage with this and see what I can do! I'll also record the sound and upload it!



Again, thanks for the help.
 

·
Registered
Joined
·
2,282 Posts
Welcome to the forum. You may have a couple of different issues going on. Turning the engine with the fan is not the greatest idea. I assume you removed the small bolt in the center of the fan, and then turned the engine? Even if you left the bolt in, I surmise that you have spun the fan on its shaft and now you are turning the shaft faster than the fan. Maybe not, you could have been lucky. I would work on getting the front inspection cover off by tapping a 6 point 17mm socket onto the remaining flats, or using a Vise Grip type of pliers to grip the rounded head. Replacements are readily available and not expensive. As a last resort, use a cold chisel on the perimeter of the cover to tap it loose.



Now for the valves. Are you sure that you had the piston at TDC on the COMPRESSION stroke? If you followed the link you noted, it says to watch the intake valves closing and then watch for the mark to appear. I would think that turning with the fan and watching marks could easily throw you off one revolution.



You can remove the fan with a M14x1.5 bolt about two inches long. Just thread it into the center hole of the fan after the attaching bolt has been removed and tighten it up. The fan will pop of its tapered shaft. You may have to tap the end of the bolt several time (I said tap, not beat), and re-tighten if it is stubborn.



I think your noise may be the fan not being secured to the shaft. When you get it off, you can start and run the bike for a few seconds to check. If the fan is spinning slower than the shaft, there will be much less air flow thru the radiator and the heat cannot be transfered to the air.
 

·
Registered
Joined
·
2,618 Posts
If we assume that you were at TDC on the exhaust stoke (assumed because you had zero clearance when you checked them) you most likely now have MORE clearance at TDC on the compression stroke. Maybe that accounts for some of the noise if it is not the fan. And that should also help you find TDC compression now that you have clearance at both compression and exhaust. The TDC with the most clearance now will be TDC compression.



As for the overheating, when you re-installed did you allow the radiator to "burp"? Bring it up to temp - meaning the thermostat has opened- with the cap off and then top it off.



My manual says to turn the motor using the rear tire. Basically nonsense if you know about the 17mm bolt in the front, but given that you can't get to that right now you could put it in gear and rotate the tire until you are at TDC. It is, of course, much more difficult and time consuming to do it that way, but still possible and better than using the fan.



Fib
 

·
Registered
Joined
·
4,035 Posts
...........

The tappets were so tight, that the valves were not opening fully. This caused the bike to be sluggish. When I set them properly, they were letting in the right amount of fuel, causing it to get hotter and also making it more responsive, however my cooling system needs flushing.



Im starting to go crazy over this, so ANY help is very much appreciated.



Thank you so much for reading!




Welcome to the forum!



All good info above. I just wanted to correct a possible typo.....



If the vavles/tappets were tight, then they would not close fully.



Regards,



Dan
 

·
Registered
Joined
·
5,563 Posts
hi decoding from far from the madding crowd?...lol a warm welcome from spain.

you have all the help you need already on this thread,so i wont say a word.

one tip for the future,only from my angle.



split your issues/questions into more threads....so many tied up in one thread for me[at my age.lol]is hard to concentrate on.

ok guys stop laughing
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #9 ·
Hey guys, thanks for the replies. I'm inches away from taking this to the garage. Haha. I'm having the use the back wheel. Problem is, I don't have a clue when the bike is at the correct tdc. Apprently both sides of the tappets should have play in them. But I can't seem to get to that point. 3 days worth of work just on these bloody valves.



Thanks all for your help though.
 

·
Registered
Joined
·
5,563 Posts
Hey guys, thanks for the replies. I'm inches away from taking this to the garage. Haha. I'm having the use the back wheel. Problem is, I don't have a clue when the bike is at the correct tdc. Apprently both sides of the tappets should have play in them. But I can't seem to get to that point. 3 days worth of work just on these bloody valves.



Thanks all for your help though.
hey,you might never find a position when[at tdc]you will find slack,the click.all depends on who adjusted them last,and what they did.



foolproof method for finding the compression stroke...........

spin the engine useing the front 17mm nut.set wrench to tighten,and dont change that setting for anything.

plugs are out anyway,put a t-bat screw driver,or the like down through the cylinder till it rests on the top of the piston.as you turn the crank,your driver will rise and fall,watch it.when it starts to rise,take the driver out and put your finger down into the plug hole and block it up,keep turning,you know for sure by the compression on your finger,when its the compression stroke,youl feel it.then look at your valves,both will be closed when you carry on turning and align the tdc mark in the flywheel apperature.

then you set your valve clearance.

i call it the feel and see method......feel the compression and see your closed valves.

 

·
Registered
Joined
·
6 Posts
Discussion Starter · #12 ·
hey,you might never find a position when[at tdc]you will find slack,the click.all depends on who adjusted them last,and what they did.



foolproof method for finding the compression stroke...........

spin the engine useing the front 17mm nut.set wrench to tighten,and dont change that setting for anything.

plugs are out anyway,put a t-bat screw driver,or the like down through the cylinder till it rests on the top of the piston.as you turn the crank,your driver will rise and fall,watch it.when it starts to rise,take the driver out and put your finger down into the plug hole and block it up,keep turning,you know for sure by the compression on your finger,when its the compression stroke,youl feel it.then look at your valves,both will be closed when you carry on turning and align the tdc mark in the flywheel apperature.

then you set your valve clearance.

i call it the feel and see method......feel the compression and see your closed valves.



Right, I decided to have another crack at it. I started by not using the back wheel, and just attempted to get the front inspection cover off. I did, and I followed the quoted instructions (Thanks by the way!
) I also tightened the cam chain while the left side was at TDC. I put it all back together and fired her up. Sounds like a dream. No rattling, no knocking. I only have to sort out the cooling problem now - which someone pointed out about bleeding the coolant system - something I didnt do. I just wanted to thank you all for your advice, and the fact that you all saved me £100 for a garage to do it.



Just gotta order a new inspection cover now! Again, thanks for all your help!
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #13 ·
hi decoding from far from the madding crowd?...lol a warm welcome from spain.

you have all the help you need already on this thread,so i wont say a word.

one tip for the future,only from my angle.



split your issues/questions into more threads....so many tied up in one thread for me[at my age.lol]is hard to concentrate on.

ok guys stop laughing


Motorbikes have no age limit!
 

·
Registered
Joined
·
948 Posts
Right, I decided to have another crack at it. I started by not using the back wheel, and just attempted to get the front inspection cover off. I did, and I followed the quoted instructions (Thanks by the way!
) I also tightened the cam chain while the left side was at TDC. I put it all back together and fired her up. Sounds like a dream. No rattling, no knocking. I only have to sort out the cooling problem now - which someone pointed out about bleeding the coolant system - something I didnt do. I just wanted to thank you all for your advice, and the fact that you all saved me £100 for a garage to do it.



Just gotta order a new inspection cover now! Again, thanks for all your help!


Hooray!! Stick around and keep us posted.
 

·
Registered
Joined
·
8,423 Posts
Right, I decided to have another crack at it. I started by not using the back wheel, and just attempted to get the front inspection cover off. I did, and I followed the quoted instructions (Thanks by the way!
) I also tightened the cam chain while the left side was at TDC. I put it all back together and fired her up. Sounds like a dream. No rattling, no knocking. I only have to sort out the cooling problem now - which someone pointed out about bleeding the coolant system - something I didnt do. I just wanted to thank you all for your advice, and the fact that you all saved me £100 for a garage to do it.



Just gotta order a new inspection cover now! Again, thanks for all your help!


Great work.Don't give your money to garages.99% of the jobs on these bikes are easy for the home mechanic.That's why many of us love them,among other things




John Oldfield(Great bloke) has the 17mm Tappet covers(that's one of their names.There's 3 of the same on the bikes.The Front crank shaft cover,one on the rear engine case depending of the oil breather system and one on the rear drive unit).



http://www.johnoldfield.co.uk/



Use Ctrl+f on this page with this number,



http://www.johnoldfield.co.uk/parse.php?file=LISTB.TXT



12361035000



£2.85 plus whatever
 

·
Registered
Joined
·
5,563 Posts
well done,sometimes on old machines you need to feel it,not just see and do.

 
1 - 16 of 16 Posts
Top