84 XR500 Rocker Arm Noise?

[wfaps]

I just replaced the cam chain in my 84 XR500 because it was making noise. It was actually hitting the top of the rocker cover. I started the bike and it still has a tapping noise coming from the rocker cover/cylinder head area.and less noise than before I changed the chain. I believe this noise was there before but I could not isolate it because of the cam chain noise. I replaced the guides, chain, crank and cam sprocket and tensioner spring.

Here is the symptom:

If you are sitting on the bike with it running it makes the tapping noise, but if you lean the bike to the right about 10-15 degrees the tapping noise goes away. I have re-adjusted the valves and that did not make a difference in the noise.

Has anyone else ever experience this? I am just looking for a possibility and a direction to go before I take the engine out of the bike again and start digging.

Thanks,

[wfaps]

I found the problem. A previous owner of the bike must have had the rocker shafts out of the rocker cover and did not put one of the wave washers back on the rocker shaft. The wave washer preloads the rocker arm to one side and keeps it from rattling. I lucked out in that I was able to install the new wave washer without having to disassemble any of the engine. I was able to install it through the rocker arm adjustment caps. It's amazing what a $3.22 part can do for making an engine quiet.

[Horri]

Interesting find. My 86 XR600 has supposedly had a new Cam chain put in it along with all new bearings, Piston etc and it still rattles like a b.....r in the top end area. (Tappets are adjusted correctly) I'm going to check your find on my bike at some stage just in case the reco guy or a previous owner left something like that out..

[srsneedofhelp]

I too have an 84 xr500r.

Under load (mid throttle) if I get on it I get a ticking sound from the top end, this only happens when the bike is hot. I am collecting parts to rebuild the entire top end (cam, cam chain and sprocket, valves, rockers etc) and I'm wondering if this could be caused by the cam chain tensioner allowing the chain to wear on the head. It is feasible to replace just the spring or should I be buying the entire OEM lifter assembly as well as the guide?

Thanks,

Anthony

[wfaps]

Mine had the same kind of problem in the beginning. When the engine was cold it made very little noise, but when it heated up the noise got louder. I put my fingers on the cam chain tensioner (where it goes through the head) and would load it clockwise and the noise would get less. So I replaced the cam chain, cam shaft gear and tensioner spring. When I did, the top of the rocker cover was eaten away from the cam chain hitting it. This got rid of 90% of the engine noise on the bike except the rocker noise that I just fixed with the wave washer.

[srsneedofhelp]

Cool I'll start there. Thanks for the advice.

[rodhw]

Hi

Looking for some help with a xr500 82.

i dont understand why the rocker arms are not pretensioned so that they run on the cam shaft all the time. i have just fitted new cam shaft, but here in South Africa i cant get new rockers. after starting the bike i could hear a nasty rattle in the head so this evening i took the engine out and took off the tappet cover. What i found was that the rocker arms were damaged and the cam shaft from the impact of the the rockers not traveling around the cam shaft.

hope im explaining this properly

im new to this forum so i hope im posting this in the right place!!!

any help would be great, been restoring this bike for 2 years now and getting a bit desperate

Rod

[thumpharder]

the damage may be from notsetting the valve clearance after the new cam, or more likely no oil to the head at start up. If it's been sitting for awhile the oil pump could have lost prime. When I had mine apart and got it back together, I poured one quart oil in the frame, and one in the right hand intake valve adjusting cap. This made sure oil was in the head, and it drains some right down to the sump. When you get it back together and it's time to start it, loosen the banjo bolt on the head a little so you can see if oil is pumping, if after 10 seconds you have no oil, shut it off. I've heard some guys have luck priming the pump by using low pressure to pressurize the frame through the breather hose that goes to the top of the engine, remove from head and apply pressure to force oil through pump.