Bro just saved me some cash. I pulled yhe valve cover and found the retainer clip came off the valve. Took some time getting the spring loaded and clip on (zip ties on the spring) adjustments made and fired right up!!!! Thanks man. Next round on me
Thank you for this VERY informative video,I have 525 hrs. on my 2020 Onan QG 4000 Gen in my Toy Hauler,it started with some mild serging,so I did some maintenance,changed the air filter, fuel filter and spark plug,still mild surging,cleaned the Carb at the altitude adjustment screw and did the mod,the mild surge was 99% gone,I came across this video to adjust the valves,, the valves were way loose, valves were easy to adjust, just time consuming,putting the Reed Valve and gasket in place then putting the cover back on was a different story,evidently the reed valve came out of position,"you can not see this once the cover is installed",so while tightening the cover "crack"yep cracked the cover,had to purchase a new cover and gasket $90,ouch,this time I sprayed the back of the gasket with some gasket contact glue,inserted the reed valve then put the gasket in place to hold the reed valve in,the glue did the trick,it held the reed valve and gasket in place so I could install the Cover,NO more surge,purrs like a kitten.
This is how I fixed mine. In the case of: "I CAN'T START MY GENERATOR" It's has been two years since last time it was running, so I started by checking oil level full at gen (it won't start if low oil becouse of sensores), gasoline more than 1\4 tank in my RV (also safety censors), sparkplug checked for good spark, check the manual circuit braker (ON) at front RV engine compartment for current, also cleaned the carburetor and even installed new one but same situation, then checked wires and found some has been chewed by rats so I replaced them, by this time it started but stay runing only by keep pushing the switch on all the time, so I knew it was electrical problem from the engine itself, so I took the generator out from my RV to work in my garage, ( I did this by myself with some tools and old tricks) it's really heavy for one person. I disassemble the unit at my garage and started by removing the cover, then the cooling fan or flywheel unit (it's 2 items in one unit) until finally I was at the gen rotor and brushes assembly area and this is what I found: one more wire chewed by filthy rats plus the stinky rat nest in the middle of the generator motor coil, I fixed the wire and sanded the commutator copper contacts where the brushes are sitting becouse they were real duty with old urine from the rats. Then I assembled everything back together and bingo it's runing like a champion. For this project materials involved was about $60.00 including an aftermarket new carburetor and an harmonic balancer/steering wheel puller (available at any auto parts for $25.00) to pull the aluminum fan out and (flywheel). Just picture this: (Eny engine run smooth if gasoline and DC current aren't interrupted) so following this important principle you'll always find the problem to be fixed. Also if you have a onan microlite 4000 like mine, don't run it for more than a minute without the cover becouse you'll cook the engine real fast, also keep the eye on the aluminium fan and your fingers after cranking it in case you missing one or two members...just kidding. After testing the gen then put the air cooling assembly back and the rest of components including the cover and done!!! If this can help eaven one person save time and $$$ it'll make me more happy, thanks for reading!!!
Great video thank you so much, right now I can’t even get the .002 to slide in, hopefully when it cools totally off in the morning, I can give it a go. Mine will run for five minutes and then it shuts itself off Thank you.
Thank you so much for this, it will save us so so much money going forward. Our generator is tucked away and bolted in the trailer in such a way we can't get it out on our own to change the fuel filter 🙄 at least this way that's the only thing we will have to have a professional do.
Yeah idk why Cummings made it so hard to get information on maintaining these, especially since they’ve been around for so long. I’m hoping this video can get spread around the community to help people save money. Thanks for the view! Let me know if there are any other topics you’d like to see a video on.
Hey no worries. Glad you enjoyed the video. I do not know the specs. I'm sure with some digging you'll be able to find them buried on the internet somewhere.
Thank you for the informative video. Mine has a backfire type issue and wont start. It looks like a valve issue. How would know if its a broken rod since you cant see what they are doing? Thanks
I lashed mine to .02 instead of .002 and have been wondering why I get crank no start. I will get a better feeler gauge and do it properly. Wish me luck, great video btw
I am having trouble getting my Onan 4000 started, i replaced the fuel pump and filter and the carburetor, now it is backfiring and still won’t start can you please help
The top nut is for locking in the tolerance,the bottom nut is for setting the tolerance,but because you are turning the top not against the bottom nut,the bottom nut tends to move and will change the set tolerance,that's why you have to be patient,it will take many attempts to get it correct,what works for me is to insert the feeler gauge,with your fingers tighten the bottom nut,then hold the bottom nut with your wrench,try NOT to let it turn while tightening the top nut,check the tolerance again,keep doing this procedure till you are satisfied.
What is the “accordion” piping on the right hand side? And what is the purpose of it? When watching this video, I just realized on my generator that pipe is actually not sitting in place
I believe that is to transfer heat from the exhaust system to linkage that auto adjust the carburetor. As the engine runs from cold to hot it has different intake needs. I would imagine it could cause some idling issues if not in place.
Great video. I dropped a valve, had to replace the retainer. Followed your steps, worked fine. Ran it for an hour under load with the AC and shit went south. It just died. Let it sit, fired it up, same thing. Did this three times. Ran great, then died under load. Hell it even died with a load. Starts chugging and dies. Fault code 36. Any guesses? Anyone?
That would be a great video. Maybe this season I’ll have the opportunity to demonstrate it. From what I remember it can be a little tedious but it’s not that bad.
The cover has numbers stamped on them for the order in which to tighten. if you can't find the gasket you can you can use high temp silicone gasket maker. Im not sure of the torque, just nice and snug has worked well for me.
My generator fires up perfect and runs perfectly for about 10 minutes then it turns off and will not start till completely cold You think this will help?
Hey Eddie, does it stall out under load? Basically when you start turning on appliances? Or, does it just naturally stall when you aren't doing anything?
@@eddievaldez7103 hmm... that's a tough one for sure. Sounds possibly heat related. There's a chance that the control model for the generator is getting "heat soaked". Basically the computer for the generator could be getting too hot. I would try switching out the control module for a known good one, and see if that resolves the issue.
If I remember correctly, right around the 500 hour mark. But like I state in the video, I would check it every 400 hours or at least before a big trip. Might even be a good idea to just store the tools in the RV needed for the adjustment just in case. Would be a major bummer to not have AC during this heat wave. These generators have been giving me a lot of headaches this summer. One blew up completely, another had a fuel pump go out. So I developed an alternate solute to basically "delete" the generator and put in something else. I'll be filming that process for the community for anyone interested. So please subscribe and stay tune for more tips on taking care of your RV and automotive vehicles!
Yee gads! This guy must be working for NASA on the space shuttle. I'm all for accuracy but this sort of precision is a bit of overkill. That two thousandth likely will disappear as soon as the engine heats up. Which is what the gap is intended to do. If you're not as precise as this fellow is, just error on the loose side. With lashes that close, the valves will easily hold open when all of those parts start expanding which will cause a lack of performance or even shut down. There is no reason these engines can't handle a looser gap. I know what Onan say's, but they are notorious for overstating procedures. Say goes for the 500-hour inspection. If it's working well, leave it alone. You're likely to do more harm than good. All IMHO of course.
Better safe than sorry,I have a 2020 Onan QG 4000,the owner's manual says check the valve clearance every 430 hrs.I did not pay attention to this,4 yrs later at 550 hrs the Gen started surging ,I replaced the fuel and air filter,cleaned the carb but still was not running properly,it finally quit running,said ok let's check the valves,I pulled off the valve cover and immediately seen the problem ,a very loose and cracked rocker arm,I replaced the rocker arm set the lash "clearance" in the valves .002,bam problem solved,purrs like a kitten,lesson learned,Onan set the maintenance schedule for a reason,now I follow it.
