I’ve got a Chinese 420cc engine that has a rattle when running that’s been getting increasingly louder as of late. It’s also been harder to turn the motor over with the pull cord when starting it as well. I imagine the problem is something serious but just wanted to run it past someone before retiring it.
#2
Scrubcadet10
Valves probably need adjusted, I think 420CC Predator engines call for .005" intake and .007" exhaust
#3
Hammermechanicman
Sounds like the con rod big end is about to expire.
#4
Scrubcadet10
It could be what Hammer said, but i've read and watched where it seems these Chonda motors clack alot when the valves are out of adjustment.... pop the valve cover off, check clearance with feeler gauge... if they check out Hammer is probably right,.
Thanks very much for the quick replies. After taking a second look at it, i noticed the shroud/ heat shield encasing the muffler has multiple weld failures and other metal fatigue issues. I’m gonna rip it out and see if it’s any quieter. Thanks for the feeler specs on the valves. I took the cover off there earlier and will attempt adjusting tomorrow. Intake valve is on carb side, right?
When checking the valve clearances, I found the stud that holds the rocker arm on the exhaust side nearly sheared off. the bucket tappet (if that's what it's called) popped off and the rocker arm itself is badly scored on the side where it makes contact with the valve. I've been trying to source parts, but that has been challenging. I looked at an exploded parts diagram of the predator engine and visually everything looks identical. The only problem is harbor freight only seems to offer a handful of parts for it, none which are what I need.
Thanks for the reply. It's a Honeywell generator. I contacted the company (which is now owned by Generac) and they informed me my machine was made prior to their acquisition of the brand and they have no info on it. I looked over the engine documentation on their website anyway but all itinerations of the 420cc generators have different looking valve train components. From browsing online, i've noticed the honda gx390 has parts that look identical to what I need. I don't know if that means they're interchangeable.
#10
Scrubcadet10
I looked on ebay to see if i could find some 420cc clone heads but most people are just selling the bare head, no parts...
