CAM CHAINS

Posted: Sat Jan 14, 2006 10:09 pm

HELLO TO YOU GUYS IN THE NEW WORLD. IN THE UK CB1100F's WERE NOT IMPORTED, SO PARTS ARE NON EXSISTANT. I OWN A CB900FA. YOU CANNOT GIVE THEM AWAY OVER HERE, BECAUSE OF CAM CHAIN FAULTS AND OTHER MOTOR PROBLEMS. CB1100R's ARE NEVER "FIDDLED" WITH AND ARE ALMOST EVER BROKEN. IS THE CAM CHAIN SYSTEM DIFFERENT ON THE 1100'S TO THE 900'S AS YOU NEVER SEEM TO TALK ABOUT CHAINS CUTTING BARRELS IN HALF ,TALKED ABOUT OVER HERE.

Posted: Sat Jan 14, 2006 10:42 pm

The tensioners are somewhat different between the engine Mk's 750/900/1100/1100R, but the operation and overall function is identical, so we are all dealing with the same issues. We do see the cylinder blocks near to cut in half due in part to poor maintenance practace's and or tensionor failure. Note: Failure may not be catastrophic in nature, it may only be a failure of the tensioner to respond to the normal "adjustment procedures" as outlined in the manuals.

If you performed the procedure,then one believes he's made the adjustment and all should be good with the world, right? Well this in more then one case is not true. The front tensioner is noted for sticking in its adjustment bore which of course would mean that any attempt at "normal adjustment will net you zero effective change in the chain tension.

I should think that the success rate of the board members in keeping this cam chain system and related failures in check is more related to good preventive maintenance practices as anything else. And perhaps a good ear for what sounds wrong in the cam chain area's. Noise will help detect impending doom. If you make the adjustment and the noise does not change,..did you in fact adjust anything? The wise man might then choose to park the bike and dig a bit deeper into the cause of the noise.

We are all collectively in the same boat here, you are not alone.

Just a couple other comments in closing. Please go to your "profile" page and update your location. There may be someone around the corner that is riding an F and you can help one another out, or maybe go for a pint or two and chat motorcyles. It's a site requirement. Also,..could you turn off the caps lock,..most relate that working in caps only is "YELLING AT YOUR MATES"! and, Welcome!

Tony

Posted: Sun Jan 15, 2006 12:53 am

Tony "Man of Information and Proper etiquette" Bagley.

Gandog try to do a search as well this will turn up a lot of information off this site.

Posted: Sun Jan 15, 2006 12:58 pm

Gandog,

Yes, there were many improvements to the lower cam chain tensioner on the cb1100F & R (they use the same lower tensioner). The upper tensioner also built a little stronger.

I think the main problem with the cam chain failure is the lack of proper adjustment of these tensioners. In any case, the 1100 is better than the 900/750.

By the way, I am typing this from the Heathrow terminal as \i am traveling through your country.

CB1100F Joined: Mar 03, 2004 Posts: 3278 Location: Seattle

And hopefully he has my bottle of Scotch in hand, to boot........ Cool

Posted: Fri Jan 20, 2006 9:03 pm

Hey guys!,

I dont mean to divert attention to myself, but I "adjusted" my cam chain according to Clymer's specs because there is only a very slight "ticking" that sounds like its coming from the right side of my engine.But it didnt change after i adjusted it. Any idea what it could be?normal engine noise maybe?

And also, what are some good precautions for the cam chain/tensioner?
BTW,its a 1981 CB900F with ~16000 miles on it and i change the oil every 1000 miles.

Sorry this is sort of the wrong thread for this but i figured i could just continue it a bit. Embarassed

CB1100F Joined: Mar 03, 2004 Posts: 3278 Location: Seattle

You have to adjust BOTH adjusters to completely kill the tick. I do mine with the engine off, first adjusting the one between the carbs, then the front one...all the while, turning the engine over with a wrench or socket assy. Usually be the 3rd rotation the chain is locked and loaded.... Cool

Posted: Sat Jan 21, 2006 2:48 pm

K. Thanks! I'll try it again. Rolling Eyes

Such a stupid design. Personally,i would rather have a positive adjustment and reliability over ease (or laziness) of use. Evil or Very Mad

CB1100F Joined: Mar 03, 2004 Posts: 3278 Location: Seattle

Remove the spark plugs. It will make it easier to crank the engine... Cool

Posted: Sat Jan 28, 2006 10:34 am

Bob, back at heathrow on my way home. Will pick you up some scotch today at duty free. Had dinner up in london last night and found a scotch store that had a huge collection of scotch. They had three bottles of black bowmore at

CB1100F Joined: Mar 03, 2004 Posts: 3278 Location: Seattle

Way kool Martin!! Have a safe flight!!!

We will have to stop by and visit Steele again.. Cool

Posted: Sun Jan 29, 2006 12:44 pm

Hey Guys,

Our F's are known for there camchain problems, but I personally think that with normal 'proper' service it will give little to no problem at all.
I own 2 900's with 120tKM on and both of them show only normal wear.
One of them I own from new, 1981, the other I purchased second hand. I replaced the camchains at 60tKM as a precaution. What I think works well, is servicing with the camcover removed so you can see what you do and what is happening. Sometimes the tensioners stick and need a 'friendly' tap on the head.
Good luck and drive safely,

Rob

CB1100F Joined: Mar 03, 2004 Posts: 3278 Location: Seattle

Quote:

Our F's are known for there camchain problems, but I personally think that with normal 'proper' service it will give little to no problem at all.

Actually, I respectfully disagree. Name one bike that is over 20 years old with 30k+ mile on it, that wasnt properly maintained, that wouldnt have cam chain problems?? Flat spots occur on rubber guides thru months of sitting in an old barn. Old, dirty, contaminated oil also contributes to premature failures. It is NOT an inherant design problem. I submit that if a 900/1100F was ridden every year for 3k miles a year, oil and adjustments routinely done, an F bike would easily make it to 80K with the stock Cam Chain and tensioners.

My 1977 650 Kawasaki had aver 54K on her when I sold it. STOCK guides and chain still aboard. NO tick, no broken chain. 3 years later I heard she was still on the road.

Im on 64K with the original chain and a new upper adjuster... @ 50K when the valves were done the lower adjuster didnt look that bad. Thats why it wasnt replaced upon disassembly..

Change your oil regularly, and keep the cam chain properly ADJUSTED!!!

Posted: Sun Jan 29, 2006 7:11 pm

I can't help but to notice that the vast majority of those claiming high mileages with no camchain/tensioner problems seem to be in cooler climes than here in Texas. Practically every bike I've ever disassembled that had 20K+ mileage had some form of heat related cracking in the rubber coated tensioner parts, usually by 30+ they were blown up. Is it the heat here? I'm sure SOMEBODY has run a non-watercooled bike here longer than 40K without rebuild but I haven't met him (her?) yet. The rings/pistons/cylinders hold up well but rubber cam tensioners just seem to cook until they break (or until exhaust valves burn,second big problem). Before they started using other the police bikes here (Kaw 1000) got a rebuild between 40-50K for tensioners coming apart.

Posted: Sun Jan 29, 2006 8:17 pm

Hello,

Like to comment on the fact that the F's are known for the camchain problems. What I mean to say is that 'without the proper service' they are known............etc. In the 30 years that I ride motorcycles, and yes I'm that old already!, I have seen some very bad cases. I think that the majority of these 'problem cases' are because of poor servicing. I believe that the F, and the K's are well constructed machines but that some of us think that you can 'hop on and enjoy' without looking after the bike.
I agree, to some extend, that there might be a possibility that the summerheat, in some of your states, might have to do with some of the tensioner problems. At this moment I'm overhauling one of my CB900 engines and the tensioners are in relative good shape, but I'm changing them anyway.

Safe riding, Rob.

Posted: Sun Jan 29, 2006 8:54 pm

Realsitically it is the design itself.

The 750/900 type comprised of a bowed piece of metal covered by rubber is subject to a constant vibration caused by even the valve springs,never mind the big force of trailing throttle. This,I think is the main reason for the spider web of cracks I see in every engine I break down. You can also get a failure at the "eye ends",but the cracks are the main problem.

The 1100F/1000C type of solid lever mounted on links is not as subject to these vibrations and holds up better.

The main question is why the 1100 type was not used as a replacement part for 750/900 bikes and was in fact then removed from inventory,ie they obsoleted the better part. The 1100 part will fit any model,the different part is the upper mounting bracket that is different between 750 and 900/1100 models to make up for the different stroke/cylinder length.