oldguy Posted February 22, 2009 Report Share Posted February 22, 2009 Hello, I have a 1973 TL125 and would like to adjust the cam chain tension. I wonder if some person experienced with this could give me a quick lesson. I've looked all over the internet, but I can only find information about later years. Mine has a screw with a screwdriver slot, with a locknut on it. Thanks for any information. I bought it used in 1975 and have never done much to it except routine lubrication etc. It's been totally dependable. I used it for a trail bike for several years, but now I just use it for getting around my property mostly. I just put a new seat on it. The old one was about gone. I don't plan on doing much to it, so I don't really need a shop manual. I think I should probably adjust or replace the cam chain though. I don't want it to get too loose and cause damage. This is my first post here, I hope it works properly. Quote Link to comment Share on other sites More sharing options...
tlrider Posted February 23, 2009 Report Share Posted February 23, 2009 Hello Oldguy, To adjust your camchain: I do it with the engine running at operating temp so I can hear it. 1) loosen the locknut on the adjusting screw located behind the cylinder on the left side. 2) adjust the screw counterclockwise listening for a change in sound 3) tighten and loosen several times as necessary for your confidence level 4) tighten the locknut 5) do not overtighten the chain as the cam journals are machined right into the aluminum head. Overtightening will cause premature wear to the cam journals. An alternative is to remove the altenator cover on the left side of the engine, this is not in an oil bath so if you lean the bike to the right you won't lose any oil. You will be able to see the cam chain behind the rotor and should be able to see it tighten and/or slacken as you adjust the screw. This method is with the engine off mind you. I'm glad to hear you are doing this. I bought a parts bike from a guy who never adjusted the camchain on his TL. THe camchain ate through the camchain tunnel on the inside of the cylinder. Looking from the front of the bike there is a narrow space between the cylinder wall and the camchain tunnel on the right. He let the bike sit dissasembled for about 10 years so it became a parts bike. Good luck... 1 Quote Link to comment Share on other sites More sharing options...
oldguy Posted February 23, 2009 Author Report Share Posted February 23, 2009 TLrider, Thanks a lot for the info. I'll take a look at it tomorrow. I'll probably pull the cover off just to see what's going on in there. I tried turning the screw out quite a ways with the engine stopped and didn't feel any resistance. Hope I didn't damage anything. Possibly the chain is just very loose. I don't know if there is a spring that tensions the chain, or the screw pulls directly on the tensioner. Thanks again. Quote Link to comment Share on other sites More sharing options...
tlrider Posted February 27, 2009 Report Share Posted February 27, 2009 Oldguy, The adjustment screw attaches directly to the tensioner via a sliding yoke if you will called a hinge item #20 in the parts list. THe top of the tensioner is anchored by the bolt (#22) on the head to the rear of the points cover, there is no spring. Adjusting the screw moves the hinge up or down causing the tensioner to bow. See the parts diagram here: http://www.mrcycles.com/fiche_section_deta...4&fveh=3705 This is an online parts fiche, the link should take you to the page with the cam chain and tensioner. If not find the Honda Parts menu on the left of the home page, click Honda Motorccle Parts, pick year and model then desired parts diagram. The exploded views are great for understanding what's going on. Quote Link to comment Share on other sites More sharing options...
oldguy Posted February 28, 2009 Author Report Share Posted February 28, 2009 TLrider, I pulled the left cover off so I could see what's going on in there. Once I could see the chain it was easy to adjust it correctly. I pushed on the slack side of the chain and turned the adjustment screw back in until I got a little movement on the chain. I had it way too tight. The screw ended up very close to where it's been for the last 30 years. I guess I haven't run it enough to wear it out. Thanks for all the help. I found a repair manual CD on Ebay. It will be interesting to look at it even if I don't do anything major to the bike. Take care. Oldguy Quote Link to comment Share on other sites More sharing options...
brian r Posted March 2, 2009 Report Share Posted March 2, 2009 Glad you got it. Most folks make the mistake of screwing the screw in thinking that they are adding tension. TL Rider gave you good advice!! Quote Link to comment Share on other sites More sharing options...
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