ohiofarmer 3,155 #1 Posted August 12, 2017 (edited) I had just finished mowing the yard with my 520 with a 420 cc predator. It has been a good engine, and like a good engine should, it got the tractor back to the barn and just quit running. I was gonna replace it under the extended warranty, but the warranty had expired.. Time for an autopsy. We all know these are throw away engines, so at least something might be learned before buying another. I did not do stuff in the correct order, but the original idea was just to look things over anyway. First, i used the pull start and it moved a bit and then ---CLUNK--- Broken connecting rod,says I.. Then I turned it backwards and it clunked again.I stripped it down and took off the side cover, expecting disaster, but everything was oK and the oil sump even looked clean. It had compression so i took off the spark plug and noticed a screw missing from inside the air cleaner. The pictures tell the rest. [Look closely at the bottom of the picture of the piston] So a sheet metal screw into plastic might not win any industry awards for engineering. Couple that with a square piece of foam for an air filter with space underneath so that same screw can be sucked into the engine..The second picture shows the location in the air cleaner housing from which the bent and battered screw emerged.. The screw was big enough that it kept the piston down from TDC, so no spark happened and only one little dent in the piston and head. Two gaskets for ten bucks total will fix this engine. Now would be a good time to upgrade the air filter and install a screen for the engine air intake. Harbor Freight just came out with upgrades to the Predator engine series. The new ones have a proper paper filter that would have protected the engine from inhaling the screw. Edited August 12, 2017 by ohiofarmer 2 4 Share this post Link to post Share on other sites
Ed Kennell 35,577 #3 Posted August 12, 2017 Great Report. The little screw that could....kill a predator. 3 1 Share this post Link to post Share on other sites
ohiofarmer 3,155 #4 Posted August 12, 2017 I am wondering if the cylinder head gasket can be re-used? i have read opinions both ways. The head came off clean and the gasket is tight on the bottom side. Share this post Link to post Share on other sites
Ed Kennell 35,577 #5 Posted August 12, 2017 I have reused them on Kohlers several times w/o problems.....but, new is safer. 1 Share this post Link to post Share on other sites
953 nut 51,466 #6 Posted August 12, 2017 The Predator gods have blessed you. Don't push your luck, get new head gaskets. 2 Share this post Link to post Share on other sites
Digger 66 3,476 #7 Posted August 12, 2017 25 minutes ago, 953 nut said: Don't push your luck, get new head gaskets. X-2 ^^. Share this post Link to post Share on other sites
Jerry77 1,218 #8 Posted August 12, 2017 2 hours ago, ohiofarmer said: 520 with a 420 cc predator My questiion is :how well does the 14hp perform on the 520? That's a big difference from 20hp..what is your opinion?? thanks Share this post Link to post Share on other sites
BaySide1 137 #9 Posted August 12, 2017 question, that was only a one beer fix? 2 1 Share this post Link to post Share on other sites
ohiofarmer 3,155 #10 Posted August 12, 2017 1 hour ago, Jerry77 said: My question is :how well does the 14hp perform on the 520? That's a big difference from 20hp..what is your opinion?? thanks it runs a 48" deck just fine. Unlike some of the other predators, the maximum torque rates come at 2500 RPM. It uses a lot less fuel as well.. Not really hacking on the Onans, but i was ignorant and got too many leaves on the air intake and cooked mine 2 Share this post Link to post Share on other sites
Jerry77 1,218 #11 Posted August 12, 2017 1 minute ago, ohiofarmer said: it runs a 48" deck just fine Thanks for the reply - when my 16hp gives it up ( near future ) I don't need a lot of horses - no snowblower or FEL. just general duty and mowing....I like the idea of the cheaper predator..not willing to put the money into an Onan rebuild... ... Share this post Link to post Share on other sites
slim67 2,730 #12 Posted August 12, 2017 I had a 420 duromax in a golf cart and it started burning oil in no time. Not sure why as it had low hours but they sent me a new piston , rings and all necessary gaskets to fix it. I would still buy one again just because of price but the GX Hondas would be my first choice if money was no object. Share this post Link to post Share on other sites
ohiofarmer 3,155 #13 Posted August 12, 2017 (edited) 17 minutes ago, Jerry77 said: Thanks for the reply - when my 16hp gives it up ( near future ) I don't need a lot of horses - no snowblower or FEL. just general duty and mowing....I like the idea of the cheaper predator..not willing to put the money into an Onan rebuild... ... If you buy a Predator, do it at the start of mowing season on the 90 day free warranty. If it prooves out, buy the two year extended warranty. Be looking for anything like a pooched starter wiring or oil leaks right before the end of the warranty. Even if HFT replaces the engine, you can buy the warranty again for 50 bucks. Almost like renting an engine for 25 bucks a year. I bought one and the electric starter wiring went to smoke. instead of an early replacement, I just pull started it for almost two years and got it replaced at one week before the warranty expired. I could not believe it when they offered another warranty on the replacement engine. Also be aware that the stock muffler on the Predator faces forward and would burn up the hood on your tractor. i run mine without a hood. i suppose that you could cut the muffler pipe and re-weld it to turn sideways, but the pipe appears to be cast iron Of course you could buy that 22 horsepower Predator for $700---- but you could buy a decent Wheel horse for that---- Edited August 12, 2017 by ohiofarmer 2 1 Share this post Link to post Share on other sites
Jerry77 1,218 #14 Posted August 12, 2017 53 minutes ago, ohiofarmer said: Almost like renting an engine for 25 bucks a year. That would be a hard deal to beat ! ! Thanks for the added info.. my Onan 16 is a true gashog..don't like it for mowing 2 acres.. Share this post Link to post Share on other sites
JAinVA 4,619 #15 Posted August 12, 2017 I put a 420cc on my 416h and am pleased with it.In putting the hood back on the front of the hood needed to be modified to allow for the exhaust and carb controls.There is an after market exhaust pipe that would allow a muffler to mounted similar to a Kohler.JAinVA 1 1 Share this post Link to post Share on other sites
ohiofarmer 3,155 #16 Posted August 13, 2017 (edited) 21 hours ago, JAinVA said: I put a 420cc on my 416h and am pleased with it.In putting the hood back on the front of the hood needed to be modified to allow for the exhaust and carb controls.There is an after market exhaust pipe that would allow a muffler to mounted similar to a Kohler.JAinVA And info on the aftermarket exhaust pipe if it is not too much trouble Edited August 13, 2017 by ohiofarmer Share this post Link to post Share on other sites
cschannuth 3,795 #17 Posted August 13, 2017 23 hours ago, ohiofarmer said: it runs a 48" deck just fine. Unlike some of the other predators, the maximum torque rates come at 2500 RPM. It uses a lot less fuel as well.. Not really hacking on the Onans, but i was ignorant and got too many leaves on the air intake and cooked mine What gear are you able to use while mowing with that deck? My 314 has all it wants in second gear, high range with a 42 inch deck. My grass is pretty thick, however. Share this post Link to post Share on other sites
JAinVA 4,619 #18 Posted August 13, 2017 (edited) To the member who wanted pictures of the Predator 13 swap type in predator engine in the search box and the pictures of the swap are posted there.As to the exhaust pipe there is a fabrication company that is making all sorts of parts for the Pred engines.The engines seem to be real popular with go-karters.If you go to the un named bidding site and type in predator 420cc exhaust the products by jw fabrications will be displayed.Hope this helps.Luck,JAinVA Edited August 13, 2017 by JAinVA 1 Share this post Link to post Share on other sites
ohiofarmer 3,155 #19 Posted August 14, 2017 On 8/13/2017 at 8:23 AM, cschannuth said: What gear are you able to use while mowing with that deck? My 314 has all it wants in second gear, high range with a 42 inch deck. My grass is pretty thick, however. The 520 is a hydro Share this post Link to post Share on other sites
cschannuth 3,795 #20 Posted August 15, 2017 11 hours ago, ohiofarmer said: The 520 is a hydro Of course it is...I wasn't paying attention...sorry about that. Share this post Link to post Share on other sites
Howie 882 #21 Posted August 16, 2017 Where that screw landed it may have collapsed the top ring land, which freezes the ring in its land. Possibly even breaking the ring in some cases. No easy way to check without a teardown. Have a Honda engine here that happened to. Yours may be ok, if not May tear up the cylinder wall. Share this post Link to post Share on other sites
shallowwatersailor 3,213 #22 Posted August 16, 2017 On 8/12/2017 at 4:42 AM, ohiofarmer said: I had just finished mowing the yard with my 520 with a 420 cc predator. It has been a good engine, and like a good engine should, it got the tractor back to the barn and just quit running. I was gonna replace it under the extended warranty, but the warranty had expired.. Time for an autopsy. We all know these are throw away engines, so at least something might be learned before buying another. Harbor Freight just came out with upgrades to the Predator engine series. The new ones have a proper paper filter that would have protected the engine from inhaling the screw. Was this one of the original style 420cc Predators with the steel valve cover or the later "hemi" with the cast valve cover? Share this post Link to post Share on other sites
ohiofarmer 3,155 #23 Posted August 16, 2017 1 hour ago, shallowwatersailor said: Was this one of the original style 420cc Predators with the steel valve cover or the later "hemi" with the cast valve cover? I think so. It is a #60340 as shown here https://www.harborfreight.com/13-hp-420cc-ohv-horizontal-shaft-gas-engine-epa-60340.html Share this post Link to post Share on other sites
ohiofarmer 3,155 #24 Posted September 23, 2017 More than a month, and the parts are not yet here. I ordered them from HFT out of the service manual parts list, but what they do is get them shipped to the service center and call you back and then get payment. They said it could be six weeks and we are about there already. Good prices, however I will share with you guys when and if they ship my stuff. Share this post Link to post Share on other sites
ohiofarmer 3,155 #25 Posted December 17, 2017 Ok, I said that I would share with you when the parts shipped..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................They sent me a letter yesterday 12/16/17 almost 4 months later... That's how it works. First you call in with the order. you wait forever, but at least you do not have to send them money, and then they send you a letter and a phone number. You call them and pay over the phone with a credit card. Share this post Link to post Share on other sites