Duromax 500cc Head Valves and Carburetor Break Down

[@robertskelton2576]

Looks like a well built engine.

[@davidvail3838]

You always put out good info. Thanks.

[@axlmcintosh6148]

I recently acquired a generator that uses this same carburetor.. the carb was actually cracked, not repairable. Any chance you know where I could find the same one in your video?!

[@z1catfish]

I got an old YZ490 chassis beside the shop, looks like a potent engine, port, valve size, larger cam stock, now if someone made an affordable 3 or 4 speed stand alone trans cheap. Don't really want a comet belt setup on a dirt bike, but hey, maybe... be different.

[@igokarts4510]

Will the common 34mm Mikuni kit and header for a 420 work on this motor?

[@bigtexas7580]

*Yep, I just installed a 420 header and 34mm pwk slide carb on my duromax 500cc electric start. Had to modify the intake boot for the carb that bolts to the head but works great! The atock muffler on this beast is HEAVY so saves alot of weight going to a header pipe. Now just have to get this big boy jetted and happy.*

[@j.r.millstone]

I have one that i modified to have a better air box and bigger exhaust but now it surges at higher RPMs and needs to be choked to run right. Should i port out the jet even bigger to fix that? Any help would be appreciated.

[@redneckcomputergeek]

Yes you would need to do some jet work do to better air flow.

[@j.r.millstone]

@@redneckcomputergeek thanks man. Any suggestion on what kind of jet kits might fit it, or should I just use a drill and do it myself?

[@redneckcomputergeek]

@@j.r.millstone Well a 440 at stage one runs a 44 or 45 jet from NRRacing so my bet would be to buy 45, 46 then drill if needed.

[@j.r.millstone]

@@redneckcomputergeek thank you. Last question, what issues does that solenoid on the bottom of the bowl pose? Why get rid of it?

[@globalwarmer2]

⁠@@redneckcomputergeek I was wondering what that little jet was myself. I live at 5,600' and the main jet is a 108 and the engine sputters a little at high RPM so I put in a 102 and it sputters worse so I was wondering if I needed to replace the idle jet with a different size? Or should I go up a step or two with the main jet? This new engine is going on my duck boat.

[@reedehlers]

I have one of these in the shop now. It ate an exhaust valve. Does anyone know where to buy parts for this engine or do you have to call duroMax for OEM?

[@redneckcomputergeek]

As of right now Duromax is the only choice to get parts.

[@damiantaylor3394]

I'm going to build this engine to run on propane for my propane mud boat project

[@liljoeii6091]

Hi guys thank you for the video

[@chuckb.5076]

I like it. Thanks

[@aydenkram1749]

Free motor try to find an old lawn tractor for free do a lot of free-ish mods to it and call it FreeSkate that's what I'd do