Cam Chain Tensioner Mods
 

While I am a noob to this site, I am by no means a CBR1000F virgin. Have owned, ridden and wrenched exclusively on my '91 since mi. 5. Now have over 156K mi. There is nothing on this bike that I have not had apart. I obviously love this machine but there is one thing that has been a pain in the arse-timing chain tensioner noise! Have tried to modify using extra springs to suppliment the OEM tensioner spring, mechanically via a threaded rod that was adjustable (carefully), but none were very permanant. I have come to the conclusion that the problem lies in the fact that the oil in the tensioner is never actually "changed" and the hydraulic portion of the tensioner fails. Any thoughts on this, I'm tired of buyin $155 tensioners. Thanks guys.

Could it be that it's the primary chain that's making the noise? I too have had 4 timimg chains in 5 years, and have fitted the new type tensioner with the longer spring.It's still noisy...............

156K miles - hoooo boy - surely time for a primary if you haven't done one already ?

Hey Shadow, I'm not quite sure what you mean by "primary" chain, but I did replace all 3 chains at 84k during a complete engine o-haul. The noise is definately coming from the tensioner as any time I try something different with it the noise goes away for a while. Can verify this by mounting tensioner in a vice and while stroking it (insert joke here)can feel a "dead spot". Have drained the oil,flushed with brake parts cleaner refilled with fresh oil and it comes back to life temporarilly. Haven't bought a new tensioner in some time-when did the updated unit come out and is it any better?

The revised tensioner came out from (I think) the later models of the bike -93-96 - the difference is that the spring is quite a bit longer on the later one. Original on mine was about 1" or so and the revised one is about 1.5", maybe even a bit more. The first ones for the Fh/j models were really short, only about half an inch of spring.Sorry I don't have pics - am on my laptop......blew the motherboard on my desktop.
One thing I have noticed about the CCT, when I use slightly thicker oil, ie15/40 it seems to be a bit better, untill the oil wears thin again.Could the secondary blade on the CCT (the one you can't change without doing an engine strip, not be worn.............The primary chain is the one around the stator and crankshaft, gives you all the voltage.

Mod. version 3.0
 

After a few cocktails and some thought, I came up with an "improved" version of a cheap ( under $5) way to modify the tensioner. Have not had the chance to put any serious miles on yet, if successful will be glad to share.

Some mods can be seen there https://cbrforum.com/forum/showthrea...t=3995&page=14

Also I have added another spring to add some tension. http://public.fotki.com/kapa/cbr/ After that fix I have ride about 15000 km and the noise has still not come up. Last year ( about 7000 km back) took the CCT out for some inspection. The sliders showed some marks of wearing, but all in all it was all right.

Good to see you Kaspar !
Nice mod !
:)

Greetz to you all also:)
seems like the long and cold winter is over and i can eventually try what it feels like to ride a hurricane again:)

PS. Peter What news i have missed during the wintertime? :)

Worst news was the loss of Hardcorp 8654 in a vehicle accident, in October. That hit everyone very hard. Otherwise, the usual stuff, you know.....:)
Enjoy the summer !

Sorry it took so long to report back as it was a bad year for riding this season. The good news is that I've found what I believe is a permanent solution. First remove the tensioner, grind off the rivet that the tensioner arm pivots on , remove the arm. Then grind off the inner portion of the arm so that a 80x 5mm HARDENED bolt will fit(you will have to grind off the 1 of the tips of that bolt). Then fabricate a diamond shaped piece to fill in the opening at the top of the tensioner, slot it, and the tensioner to accept the bolt. I suggest that you weld or braze the rivet and added diamond piece to the tensioner to ensure nothing bad happens if the bolt breaks. Use a flat washer and 2 HARDENED nuts to adj. the tension. Let the OEM spring set the correct tension, then use the 2 nuts as locknuts (with Locktite) to hold that adjustment. As an added safety feature I drilled a hole in the upper timing chain guide and wired the end of the added bolt to it in case of a failure. I know this sounds complicated, but it is actualy quite easy, if you have the correct tools. Have put over 3Kmi with no problems yet on this mod., so I think it is a long term solution.