Yep, the Rincon tap. Both of mine do something similar when it's hot outside and the engine warms up. Had tensioner changed, valves adjusted. Still does it, it's simply not a silent engine.. Usually mine aren't as clackety when the air temp is below 70 outdoors and the machine runs better in general in cooler Temps. Most all the rincons I've seen over the years have a few rattles like every other Honda atv engine. They all have some sort of tick or rattle and a we've owned Honda products for 25 years in our family.. Never once any major problems, still own 3 wheelers from 1986 that run perfectly.. And they tap and tick too.. 👍🙃 man, I hope you get another one someday. When serviced properly, they last forever. Mine are 2007 models and zero problems.

Just had my chain tensioner replaced fixed my problem

Sounds like the chain for the oil pump chain right behind the timing chain is loose. I just had one come to my shop with the same problem. Its a pain to change

After talking to people, searching the web, and seeing the comments here, I'm 95% sure that if you have this issue take it to a quality repair center and have the cam chain tensioner adjusted. In all fairness this noise is probably amplified by the overall superior design and lightweight materials that Honda uses. I know the exhaust guard definitely amplifies the noise. It's ironic that they build a technically advanced/superior bullet-proof engine that never fails, but sounds worse than any other manufacturer out there.I can't afford to buy new so there is also a chance that the person who owned it before me did not change the oil as often as recommended. That is so critical with the Rincon since the engine oil is also the transmission fluid. Some people just don't get how important changing fluids is.The previous owner was also young so it may have also been ridden hard.

Check the timing chain tension. And of course the valve clearance.

my 650 Rincon has done that for years!!

I miss the Rincon but moved to Suzuki's. First a King Quad 450, then a 750. I'm done with Honda engine noises. I ride ATVs to relax not have ticking noises drive me crazy. My 750 growls and has 10 more horse power, can lock the front diff, and more ground clearance. I miss the handling and light weight of the Rincon along with the high quality materials that are used in it, but I'm willing to sacrifice that for the Suzuki's extra power and superior engine sound.

I'll deal with the noise as long as I get the longevity out of the Honda

Valves

Valves just need adjusting

Can I still used my Honda if ringing noise in engine

Mine sounds the same

Most likely it is your cam chain tensioner. Buy a manual tensioner and throw the old one away. $30 on eBay. Problem solved and easy to install. Just did it yesterday. No more ticking

My 05 650 just started doing the same thing last week not to sure why it sounds like that

Hi did you found the problem mine does the same think ... please let me know

En español: hola, yo tambien tengo el mismo sonido y recien a los 11600 Kilometros de recorrido, lo acabo de dejar en el concecionario HONDA espero lo solucionen. por favor si alguien ya lo soluciono este problema que comente..!! GRACIAS. in English: Hello, I also have the same sound and recently to 11600 kilometers, it just left the Dealership HONDA hopefully settle it. please if someone already solved this problem that comment .. !! Thank you.

Here's my noise on my 2004 Rincon. Much more clacky and makes different sounds like something in exhaust path. Goes away sometimes after hot. kzfaq.info/get/bejne/prt9dpOipszYf6M.html