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Discussion Starter · #1 ·
I have a 1981 CX500 Custom. I have everything working on it except the tach. The cable that is there spins, but doesnt have the end on it that connects to the tach. I have taken off the tank and radiator and I can see where the cable attaches to the motor. I also have a new cable.



Question...

1) Do I need to take off the fan to take the old cable off and put on the new one? (looks like I do)

2) does it simple unscrew and allow me to screw the new cable in?



Thanks so much for the help... I have been reading a lot on here and the old forum, but just now took the plunge to begin posting.



Joe
 

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You may not have to remove the fan, but getting to that locking screw would be easier. You will probably need a GOOD #2 long philips to reach the screw and then try and remove it without striping the head. It is a simple matter to remove the fan with a M14x1.5 bolt from the hardware store. About 2" long. Just remove the original mounting bolt and screw in the larger one in the fan hub. Tighten the bolt and the fan pops off. It is probably a good idea to do this just to check for cracks in the rear of the hub.



With the fan off, you can use a small Vise Grips on the head of the screw to break it loose. Then remove the screw completely and the tach cable can be pulled out of the drive. Either slide out the old inner cable, or replace the complete cable. A lot of people replace the locking screw with either a hex or allen headed screw to be able to get it out easier the next time. I have replaced a tach cable without taking anything off the bike, but wound up using a 24" extension and a couple of adapters to reach this locking screw. Before you install the new cable, insert it into the tach end and spin with your fingers to make sure nothing in the indicator has locked up. You don't want to replace it again.



And welcome to the forum. Stay around and share your experiences with the rest of us. And double thanks for putting your location and bike model in the profile. I wish all newbies would do this, it would save us a lot of typing.
 

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Discussion Starter · #3 ·
Thank you for the quick response... I'm going to Lowe's now to buy a bolt and take the fan off.



I'm excited to be in group. Ive never owned a motorcycle, but found this one on craigslist, a great all original bike, perfect seat and just normal wear and tear. Ill post some pics soon (when I have it all back together). thanks again for the help.



Joe
 

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You may also want to replace the bolt holding the tach cable in place with one of a hexed head in case for some reason you have to do it again.



I once changed a cable where I needed to use vice grips all the way because the screw head was stripped.



With a hexed head I have been able to remove and replace cables without removing anything but the cable.
 

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Discussion Starter · #5 ·
I struck out on the M14 1.5 bolt, so Ill put it on hold until Monday, luckily I have the day off. Also, I am planning to change the screw out to a hex head, but I haven't seen the screw yet, should be able to see it when I get the fan off. Thanks again for the help, I'm sure it won't be the last time I ask a question!



Joe
 

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Ace or True Value Hardware store, or whatever they call them there, will have them. Lowe's and Home Depot ain't got crap anymore and of what they do is of questionable quality.



While you're there go on Don's advice and get a stainless allen head screw to replace the old one with, chances are the exact size/pitch is in the parts fiche.
 

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Discussion Starter · #7 ·
I got the bolt this morning, popped the fan off easily, but I'm having a very difficult time with the screw. I tried it first with a set of vice grips but can't get a good hold on the screw (I did remove a small bolt that was blocking some of the access). Then I tried to unscrew it with an impact screw driver and it is starting to strip the screw... any other suggestions? Thanks again for the help.



Joe
 

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Joe, I know there isn't a lot of room there for the Vise Grip. I don't use a regular sized one, I think the one I use is probably a 6" or so. And not a needle-nosed one either. Try to just get the tip on "flat wised", rather than pointing toward the screw. Clamp it as tight as possible and just try to rotate the screw just a fraction. Once you get broken loose just a bit, it will come out with a screwdriver.



If you are using a Vise Grip clone, you might as well use your fingers. Most, if not all, of them don't work. A little heat from a micro-torch may help, but there is a rubber oil seal in the drive close to the screw. A little heat won't hurt, but don't overdo it.



Worse case would be to remove the drive and take it to a bench vise and work on it there. You will need a tach drive gasket if you do this tho.
 

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Discussion Starter · #9 ·
I was able to get the screw out (borrowed a smaller pair of vise grips) and once it broke loose, was very easy to remove. I did replace it with a hex head screw in case I need to go back into it. Once I got the cable installed, put the bike back together and cranked it, the cable spins like it should, but doesn't turn the tach. The old cable was missing the screw-on piece, so I would have had to replace it anyway. Is there anyway to change the inner female piece on the tach?



Thanks again for the help, I wouldn't have gotten close to taking everything apart and putting it back together without you guys.



Joe
 

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I don't think there is a way to change the inside of the tach. Does it not spin at all? For testing with a drill it's suppose to go counter clockwise. You should take the tach off and see if you can turn the inside at all. Otherwise it's best to find a new tach. Also make sure the needle isn't pressed up against the glass. I had one like that and it was an easy fix.
 

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As Stitch says, try to spin the inside with a drill. You might have to file a nail square or use a small square drive bit to get it to fit. The inside of the drive has square shaped, to lock with the square end of the drive cable. If you do get it to spin easily, you may just be able to lube it with a drop of oil and make a shim to wrap over the end of the cable to allow for good engagement. If the tach doesn't easily, don't try this, you will just tear the shim up. A good shim would be a strip of a soda can. You can cut these with scissors and they are very thin.
 

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Discussion Starter · #12 ·
The inside piece does spin, I was able to turn it easily, I think it may have gotten striped on the inside. I will try the shim idea tomorrow night, good idea. Ill also check to make sure the needle isn't stuck.



On a side note the owner of the Honda shop here has a 78 CX standard that someone brought in for service and never picked up. I was almost the owner of my second CX! Not sure my wife would have let me walk in the door if I showed up with another one! Thanks again for the advice.



Joe
 

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The inside piece does spin, I was able to turn it easily, I think it may have gotten striped on the inside. I will try the shim idea tomorrow night, good idea. Ill also check to make sure the needle isn't stuck.



On a side note the owner of the Honda shop here has a 78 CX standard that someone brought in for service and never picked up. I was almost the owner of my second CX! Not sure my wife would have let me walk in the door if I showed up with another one! Thanks again for the advice.



Joe


A good tach will move the needle with a simple input ie a screwdriver turning it by hand.



2nd CX? But it and hide it until you can ease her into the idea.
 

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I am ripping into my very first cx500 and found I only had about 8 inches of tach cable coming from the block. I am chasing an oil leak from the same area and got stuck at pulling the fan. Thanks for the info about the bolt.
 

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lanierjm,

Since the fan is off, thoroughly clean it and examine the inside around the hub carefully.I thought mine looked OK until I cleaned it today and found many stress cracks emanating from the hub area. I wacked the hub really hard with a hammer and it did not break or move.

Never the less, I would not be comfortable knowing I had a cracked fan spinning at 4000 rpm behind my radiator.
 

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lanierjm,

Since the fan is off, thoroughly clean it and examine the inside around the hub carefully.I thought mine looked OK until I cleaned it today and found many stress cracks emanating from the hub area. I wacked the hub really hard with a hammer and it did not break or move.

Never the less, I would not be comfortable knowing I had a cracked fan spinning at 4000 rpm behind my radiator.


I haven't got my fan off yet, but in case I find some cracks, would it be worth trying to repair with JB Weld? That stuff has repaired more things for me than I can remember!
 

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The inside piece does spin, I was able to turn it easily, I think it may have gotten striped on the inside. I will try the shim idea tomorrow night, good idea. Ill also check to make sure the needle isn't stuck.



On a side note the owner of the Honda shop here has a 78 CX standard that someone brought in for service and never picked up. I was almost the owner of my second CX! Not sure my wife would have let me walk in the door if I showed up with another one! Thanks again for the advice.



Joe


Be careful about buying another one. It can be addicting and the next thing you know you have 4 of them in the garage...




Fib
 
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