INTERMITANT TAPPET NOISE

twinegar · Post by **twinegar** » Wed Jun 25, 2008 10:47 am

With both my CBX's down I will always remember this as the "Summer of the CBX"!!!.....................dang it.

twinegar · Post by **twinegar** » Wed Jun 25, 2008 3:24 pm

Pulled the valve cover off and removed the coil pack so I can access the head easier. I loosened the nut on the verticle tensioner and tried pulling up on the top with pliars like the shop manual says in order to slacken the chain and it won't budge. Is it possible to remove it without pulling the head? Any ideas on how to free it up? I'm not sure what is causing it to be stuck.

EMS · Post by **EMS** » Thu Jun 26, 2008 12:28 pm

I don't think you will be able to get it out without taking at least the head off. The exhaust cam timing chain tensioner (the vertical one) is designed a little different than the horizontal, top one. It has two separated sheet metal channels that slide against each other and are pulled on each end by a spring. When the spring pulls them over each other the attached flexible part bulges out and presses the chain guide against the chain, thus taking up the slack. If it doesn't move when you loosen the bolt, it may be fully extended (the elongated hole in one of the channels where the clamp bolt goes through, provides the limit) Have you tried to press down on it?

twinegar · Post by **twinegar** » Thu Jun 26, 2008 4:25 pm

Thanks for responding. I thought maybe everyone was getting tired of hearing from me. I was able to get the verticle tensioner to move up and down on it's own so everything is set and fastened back together. I haven't tried the bike yet because I doubt it is the problem.

Does anyone think that overheating could be the problem since it runs like a new bike until it reaches running temp. The noise correlates with the warming weather so maybe it ran quietly in the spring because the temps hadn't reached the 80's yet.

EMS · Post by **EMS** » Thu Jun 26, 2008 4:29 pm

twinegar wrote: . I thought maybe everyone was getting tired of hearing from me. .

We never get tired of hearing from you

...and that is NOT meant to be cynical

twinegar · Post by **twinegar** » Thu Jun 26, 2008 4:35 pm

Goody and thanks for the picture.

alimey4u2 · Post by **alimey4u2** » Thu Jun 26, 2008 7:26 pm

twinegar, We are here in support of the motorcycle, nothing is better ( to me & several others on the board) than to help fellow CBXers. That being said, we are bikers too ( including Harleys that we like to joke about but mean no harm.)

"Tired of hearing from you" ? Quite the opposite.....

twinegar · Post by **twinegar** » Thu Jun 26, 2008 7:33 pm

Thanks. Any thoughts on the possibility that my bike is running hot. I did a carb job last month and lost the paper with the number of turns on the pilot screws so I set them to the basic setting. I have eliminated the tensioners and other possibilities and am pretty much left with the overheating possibility.

alimey4u2 · Post by **alimey4u2** » Thu Jun 26, 2008 7:41 pm

OK, Air cooled engines runs hot especially the CBX center cylinders, hidden behind the front wheel. Plugs ( & exhaust pipes) will tell you if there really is a problem. Too much timing advance or lean burn is normally the culprit..

twinegar · Post by **twinegar** » Thu Jun 26, 2008 7:57 pm

I haven't checked the timing yet so I guess that is next. I went to the Honda shop today and they won't work on bikes more than 10 years old but they gave me a name and number. I don't have an ear for setting fuel/air screws so I will have to hire that out. My other CBX pilot screws were set at about 3 1/2 turns when I checked them. The CBX I am having problems with is set at 1 1/4 so I guess that would be considered lean huh?

bobber · Post by **bobber** » Thu Jun 26, 2008 9:25 pm

1 1/2 turns are factory. I had a Dyno-Jet Stage 3 in a CBX once and it was set at 3 turns. Carbs have stock jetting/needles?

twinegar · Post by **twinegar** » Thu Jun 26, 2008 9:31 pm

Everything on the bike is original equipment. Isn't the 1 1/4 turns the base setting that then requires more precise adjustment.

bobber · Post by **bobber** » Thu Jun 26, 2008 11:18 pm

The bikes originlly came with "limiting caps" on the adjusting screws. Heat has to be used to get the caps off but original Honda specs were 1.25 turns. They were "lean", mostly I understand, to meet the emission regulations.

EMS · Post by **EMS** » Fri Jun 27, 2008 7:15 am

bobber wrote: . They were "lean", mostly I understand, to meet the emission regulations.

That is correct. Factory setting is on the lean side.

twinegar · Post by **twinegar** » Fri Jun 27, 2008 2:04 pm

I just finished checking the timing and it is dead on. I took an easy ride through the local neighborhoods taking it easy on the throttle. I went for about 15 minutes and the occasional lifter rattle started and slowly got worse as I worked my way home. This is definitly a heat related issue. Does anyone see a problem with backing the pilot screws out another turn and do another test drive or maybe close the choke a little to enrich the fuel mixture?