1981 CB750C valve train clatter

[joe1267]

Just picked up a super clean one owner 750C with only 9300miles. Owner just put new rubber on and had the carbs professionally rebuilt,new pads,rear shoes,plugs,wires etc. Removable windshield and rear hard bag for only $900. The question I have is about the valve train clatter I hear between roughly 4800-5000 rpm's. Engine is super quiet before and after this one small area. Makes great power. Wondering if anyone else has experienced this? Of course this 200rpm clatter is nothing compared to the noises that come from the engine of my '77 ironhead Sportster. My wife loves riding on the CB. thanks....Joe

[ccRider246]

I had that on my 750F. I wan't sure what it was but when I experienced it the valves had just been adjusted by a reputable mechanic. I couldn't say that it was definately a valve chatter but it was annoying. I think when I questioned others about it I probably identified it as a vibration but it was more of a chatter and it only occured between 4500 and 5000 rpm. Last fall I changed the chain and sprockets. the sprockets changed from the original 46/18 to 42/17. I have not noticied the chatter since. I probably just got used to it. If I am going out for an extended ride (100 or more miles) I have a tendancy to wear earplugs. I think it helps me hear the engine better. With earplugs the chatter is totally non-existent. Just my experience.

[joe1267]

Chris, thanks for your input. I figured it was nothing but thought I would ask as it is a bit annoying. I will take your advice and start wearing my earplugs on this bike as well. They are a prerequisite on my ironhead.  If this is the only minor annoyance I have with this bike, I can live with it.

[wvhardtail]

Some of that may be the cam chain. Adjust the tension and should some ease some of that. I had a Kawasaki that was the same way. Good idea on the ear plugs. Especially with the ironhead. I had one of those and boy do I miss it.

[vern401]

Check and ro adjust the Cam chain and valves.

[OTTODOCTOR]

I totally agree with vern . -- The DOHCs are critical about valve and cam chain adjustments . -- Should be done often IMHO .