Generac Engine Swap and Load Test - Worn Engine / Down on Power
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- Опубліковано 8 лис 2023
- This Generac GP7500e was purchased used in non-running condition. According to the seller, it only needed the fuel system cleaned. Once cleaned up and running it became clear the generator was not producing power. After running some diagnostics, it was determined the rotor was bad. Several months later a used generator head was located and installed. Electrical power was restored only to find about half the horse power was missing from this 14hp engine. The borescope revealed rust inside the engine and a wiped out cam lobe. The damage was sever and repair not practical. Fast forward a few months later and I was able to rebuild a comparable 420cc Generac Honda clone engine that can be swapped in. Will the rebuilt engine be able to pull the rated load of 7500 watts? Lets find out.
Ken's Small Engine Repair: @KensSmallEngineRepair
Ken's Video on this exact Generator: • Generac Gp7500E spits ...
Below are links to the 4 videos in this GP7500e series. Each video is a complete standalone video. They build on each other and make more sense if watch in order.
Part 1: Generac GP7500E - No Power Output (Stator/Rotor Swap) • Generac GP7500E - No P...
Part 2: Another Generac Generator Not Producing Power - Can We Fix It? • Another Generac Genera...
Part 3: Generac Engine Rebuild - Wiped Camshaft Lobe • Generac Engine Rebuild...
Part 4: Generac Engine Swap - (this video)
I no longer use Harbor Freight Super Heavy Duty Degreaser in my ultrasonic cleaner. Harbor Freight changed the recipe. The bottle previously stated "NON-CORROSIVE". Now it says "CORROSIVE", "do not user on Aluminum". It now damages most carburetors.
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If you want to donate to the channel, you can use the UA-cam "Super Thanks" feature or via PayPal: www.paypal.com/paypalme/james... - Навчання та стиль
I love watching you connect the wires. Please don't skip over that part. I watch your channel for the attention to detail, no drama, as well as the top-notch camera and editing work. High quality all the way and well worth my time. Keep up the excellent work.
Totally agree
Yes, ditto!
Yes!
I've followed your channel for quite awhile being that I'm retired, and cannot wait for another of your videos to be uploaded. Kinda like when I was a kid keeping up with the weekly tv shows I would watch, anticipating each one. As mentioned already your attention to detail is second to none. Top notch. Thanks for all your hard work, I appreciate you sharing your knowledge.
I noticed that one one of your videos showed you changing a metal air filter box because of a bad seal.
The seal is available from generac for about $9.00 considerably cheaper than the entire assy ! Part #0G84420152
Regards,
Sandy 🔧🏴
I've watched your videos for a couple of months now. I've owned a Generac GP6500 for about 10 years and have only put about 6 hours on it. After watching your videos I've checked valve lash which was fine, checked for the zip tie and checked connections. One connector had shrink tubing under the washer and one had the white thermal insulation clamped in the connection. The generator was working fine but your videos helped me eliminate a potential problem. Thanks!
I've had a gp7500 for about thr same time as you. I've checked the valve lash as well but not those wires, will do that asap
Considering this one was pretty close to being junk I'd say it worked out well and could save someone's plumbing or fridge full of stuff or even keep the house livable, well done
The genny is repaired at a loss, however when his power goes out the very first time, it will more than pay for itself in convenience and potential hardships. Thank you James.
You could say the spare parts have some value. Honestly the engine is probably rebuildable with a new camshaft and lifters, gasket, and a cylinder hone, and maybe a set of rings.
For "pickling" rust and insuring a fine base for repainting, investigate the following product "Black-Star rust converter". It's a product that I've used for quite some number of years now with very good results! Yup, it's one I'd care to recommend as a modern miracle in-a'jug!
James - your camera work, lighting, and sound are always top notch. Some of us are interested in finding out "how the sausage is made". When you get bored this winter, and it's too cold to work in the garage, perhaps post a little behind-the-scenes video on "the making of James Condon videos" including camera models, lighting, microphones, editing software, etc.
Enjoy your videos. One point is that since the AVR was running a little high when you were at the 7500 watt setting on the load bank the voltage appeared to be 243 volts. Since P=V^2/R the actual power is (243/240)^2 X 7500 = 7689 watts. So you were over loading the engine at the 7500 watt setting on the load bank. Also the engine speed was a little high and I would guess the engine rating would be reduced above 60 Hz. The bottom line is the engine was probably performing as it should.
First time I have seen you use that load tester. Usually it's a bunch of space heaters. Definitely a much cleaner easier way to test.
It amazes me that they have so many variations of the same machine with so many incompatible and different parts. Parts sharing is a very big part of keeping costs down. You have the same generator using different cylinder heads. different exhaust systems. different blower housings. Different power head bodies. Different carbs. . All this stuff needs different tooling, different jigs (or at least different settings for a single generic jig). Different machining. Different stamping tooling.
All this for minor difference between machines with presumably different "features" of the same family. All these differences probably help explain at least part of the cost of aftermarket parts. If you want to stock cylinder heads, it's not like there is just one per model family with each one having less demand than the full family. The cranks are probably slightly different.
Happy to see you got a nice load bank . It makes it easy to do a valid test. And James you are a awesome trouble shooter could use someone like you where i work.
Stay safe
Harry
James is no longer causing Global Warming by using 4 space heaters all at the same time. 😅
@haneyoakie14 don't worry the load bank puts out the same amount of heat just a hello of a lot more accurate.
Enjoy all your shows, very informative! Your load bank is awesome too. Nicer than a row of heaters and shop lights.
Cheers, Rich
It’s like the old family axe that has been in my family for generations. It has had 4 handles and 2 heads, but it is still the Olde Family Axe.
Ya win some & ya lose some. Ya just need more winners than losers 👌👍
At 25:00 I think you are very lucky when you attach the winding over the axle-coil (rotor to stater), in that things don't make contact when the axle rotates. Great job!
Saved another one!!! Thanks Jim!!!
yet another educational vid james always watch to the end love them!
That engine looked Nasty! Glad it worked out!
this channel helps with my depression so much it takes my mind alot of stress in my life and i learn alot about how to fix things and he breaks it down so everyone can learn
i love this channel im new but i love how he breaks down everything to a level everyone can understand
Love your videos. Interesting,informative and thorough. I know it takes a while to fix and wait for part along with editing. Wish I didn’t have to wait as long as I do for you to put videos out. With that being said, please keep up the good work
Great job James, I hope you rebuild that bad engine. Maybe evapo rust the entire engine and get a new cam and replace the bad bearing. The cylinder might hone out? Thanks for another excellent video.
Very informative video, thanks James!
Excellent videos James. Now that you have that nice load bank you could add the cost of operating different sizes of generators to your test sequence to see how long they will run on a pint of fuel. Then calculate how long per gallon, at max rated power, and convert to cost per hour so people can see how much a generator costs to operate and how much standby fuel they would need if they live in an area that has frequent outages, or if they are just going to camp. My wife works at an electric company, and people think they are getting ripped off and always tell her (she works in billing) that they are going to buy a generator so they will be disconnecting soon from the grid. HA ha, they don't realize they would be paying a lot more to operate a generator to power their homes.😅
Another perfect job!
Yepper that one was a bite in the pocket book . But at least he can recoup some of his potential losses. Great work James !
Superb, as always.
The general point is that these insrance policies (for that's what these domestic, 'in case of outages' gennies are) need very careful housing and very rigorous maintenance schedules.
I hope that the rusty engine gets cleaned up.
Again, thank-you! Superb!
I absolutely love stuff like this. It is just as exciting for me as it is for you. I could watch stuff like this all day. I built an entire Troy Bilt riding mower from scratch from my parts stash one time. I just love seeing come together from stuff that would otherwise be going in the trash.
Great job, James. At lease Jason will have a working generator. Plus you got a video out of it. Thanks for sharing guys.
I think some work with a wire wheel and soaking in evapo-rust would salvage a lot of those parts.
At this point I'd say it just needs a new camshaft and lifters and a cylinder hone. The bottom of the cylinder can be a little pitted and it would still work fine.
Thanks for your great presentation. Much more interesting ans educational then wading through commercial television channels. I am building up the nerve to rebuild a working but smoking Honda E300. Cheers, Ken .W
I just got a free 1 hour tutorial on disassembly and reassembly... God I love youtube. You're the man James!
Nice save Doc
I seriously wonder why we still build things out of iron and steel while all the time it has this overiding urge to return to it's brown crumbly state it originally came out of the ground! Excellent video as always
Because it works and it's cheap. Aluminum engine internals don't last because aluminum suffers from fatigue.
Nice one, James
Absolutely awesome video again James. The attention to detail and the patience is what most mechanics lack, you got it, and that is rare but totally grand. I´d always try to do the load test of the full rated load and let it run for one hour, better two hours, then I know everything is good for sure. Don´t be afraid of "frankenstein´d togehered" engines, as long as they make enoug power for the tested amount of time (one hour minimum), it´s perfectly fine!
Thanks for the video
Thank you for the video
Great video, the old engine was pretty bad inside when you tore it down, lots of rust. Excellent work as always James!
Thanks
The Ship of Theseus. Replacing the powerhead and the engine. Is it still the same generator? 😊 Either way, great work.
Another great project! Regarding the rust, have you tried soaking the parts in evaporust? I'm not sure how that would affect the friction surfaces however it might help with cleaning. Keep up the great work!
nice load bank !!
😀
Perhaps it would be a good educational video to teach people how to store a small engine... using something such as fogging oil to prevent corrosion and seizing of parts.
I could’ve sworn I saw a crack in that bad engine block!
Excellent video! Thank you so much. Did you happen to see if this engine had the same very strong exhaust valve spring?
You should investigate evaporust. It’s amazing stuff and totally environmentally friendly.
The damage to the rusted engine appears insignificant and not a source of the lost horsepower. The cam, the cylinder and the rings all seem within tolerance. I would like to see a video of overhauling the engine and comparing the horsepower, before and after the overhaul.
I could get it back close to 100% HP for $135 (the price of a new cam). Not sure it’s worth it given the other wear in the engine.
James, you’ve made my day 👏🏻👏🏻👏🏻
Don´t worry about loosing money. From a perspective that is looking a little furher into the futute, it is worth saving any gasoline engine out there.
I watched this video twice because I'm working on the same generator with power head problems. Trying to figure out where the problem is. I believe it's wiring but haven't chased it down yet.
Maybe the marks inside the case were water, with the oil floating on top.
Guess it's a cost/benefit thing, but I'd have rebuilt the motor with new crank/bearings/cam. But that's me, I hate throwing things out.
Nice work.
James, the background "cricket" is a nice effect ! (I hope it's compensated for the hard work, too )
It took me a week to find and evict him!
Waiting for you to post a carderator rebuild on a Owan 4000 RV generator. I have some surging that take awhile before it goes away and would like to see you do it before I give it a try.
Tks, Michael.
James: Nice job installing a CO detector in your workshop. I love watching your videos and noticed the Nighthawk in the background.
I think I recall mention of this in some earlier video, there's more than one of them, maybe as many as three?
There are four videos that tie together several GP7500 repairs. Links are in the description.
Hi James. Great job as usual. I always look forward to when your videos drop on UA-cam.
Question: do you do your dialogue while you are working? Or do you add it as sound over during editing?
While I am working.
And yet another superb video. I do like watching you take down these motors and fixing them. I also like taking 3 generators to make 1 good one😂 anyway, i would love to know where the rust is coming from, so quick question...
How old are these donor machines?
Do you think its possible these machines sat on a boat in a container too long without oil? (ya know when we had the whole shipping issues) and when the customer got them the damage had already been done and since it looked brand new(since it was) the customer used it like they should and killed it unknowingly?
Thanks for your channel and keep up the great work
Another great video James! 24% THD at full load though that is modified square wave quality power. It is horrible for home backup but acceptable for construction site needs like running a chop saw. I can tell you that running an HVAC system or a modern fridge that is built to run on DC voltage internally powered by a switchmode power supply, a generator like this would most certainly kill it in no time at all.
Not too impressed with the THD level on most portable generator. To make it worse that was a resistive load and best case scenario. It only gets worse with inductive loads.
@@jcondon1 exactly. We are starting to reach a point in the market where the portable generator power quality is so poor that modern electronic devices despite what many believe are inadequate to run them properly and they wind up damaging them even in the short-term runtime of a typical power outage.
I wonder if a really good 60 hz low pass filter would help smear out those high frequency square wave harmonics.
@@Rorschach1024 it's the quality of the power head in its manufacturing. Purity of the copper why are used it could be aluminum wire with copper cladding for example the pitch and the thickness of the wire all contribute to THD. Any kind of low pass filter because of how low the frequency is from an electronics perspective would have to be incredibly physically large to accommodate the suppression of those higher harmonics. That's why I say to everyone that it's not practical to clean up a high THD portable generator. It's good money to bad when you can go and spend a few hundred dollars on an inverter generator that has less than 5% THD
Jim, I had moisture in my lawn tractor engine. Parked in attached garage that is not climate controlled. This is a high humid area and I frequently run it for very short times to move it outside to work in the garage. The moisture is environmental that you helped me realize. I’ll be changing my oil more often and see if I can run it longer??
It's been so long, I forgot you had the load centre.... 🙂
What happened to the load bank ? You haven't used it in awhile glad your using it now in the video
I love that you have that load tester almost as much as you do. 😂
Edit: Do you use non-ethanol fuel or is that not a reasonable option in your area?
A lot of honest people around. Lol
Another successful Frankenater😅. Too bad Jason got taken for a ride on the purchase. James to the rescue.
the little bit of rust on the blower housing; wire wheel it off and throw some black paint on it...!
ok ,it quits when the fuel runs out, will it shut off with the ignition switch also?
Great watching your videos, how about some diesel generators!
Great video James. I've noticed that you are trending away from the rope in the cylinder trick for torqueing the crank. Is that because you had a complication of a stuck rope or a cracked aluminum piston? kind Regards. Craig
Have not had an issue using rope. On some engines it is easier to use flywheel nut.
got new toys nice
May I ask what state are you located? I like your videos and I am glad you don't act stupid like the others do on their videos. Thank you
NY
I enjoy watching your video's. I am curious to know if there is a UPS unit (Tripp Lite 900VA UPS Battery Back Up, 475W Tower, LCD, AVR, USB (OMNI900LCD) between the generator and a computer, does the UPS do anything to help regulate the THD? I was hoping you might run a test with the UPS in the chain, on one of your upcoming videos.
An "on-line" UPS would work but those are expensive. A typical UPS is "line-interactive" at best which can do coarse adjustments of voltage but can't do anything to the distorted shape of the waveform.
a deep cleaning of that muddy engine might just get it back to life
James, at some point could you please do a detailed video on bonded neutral vs floating neutral? My GP7500e has a bonded neutral but our interlock switch only breaks the hot lead.
If i understand this correctly then I would need to switch the generator to a floating neutral since we are technically using the houses' grounding rod. I had a look through the owners manual but it doesn't specify the procedure for doing this.I would appreciate some clarification 🍺
Dr Frankenstein lives!
Well at least you have another engine to work on when you get the chance to do that
That engine is a parts machine. Going to try to use on of the parts to upgrade a Honda GX390.
@@jcondon1 okay thanks for the update on this matter James 😃
James, In your load test, the engine struggled at about 7500 watts load. However, the voltage was a little higher than 240v, so the ACTUAL wattage was a little more than 7500 watts. (volts * amps = watts). For each 1 volt above 240v at 30 amps, that's an additional 30 watts. So you were actually loading that engine with more than 7500 watts. With this in mind, the engine was producing all the power it was rated at, plus a little. I'm betting that if you trimmed down the voltage to an even 240v, then the engine would have held strong at the 7500 watt load setting.
No, unfortunately you are not applying Ohm's law correctly, 7500Watt=7500Watt load, only the voltage or amperage can vary..😊
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@@habana7638 Your logic is sound, but not correct. You are assuming that the load will consume a consistent 7500 watts at all voltage levels. That is simply incorrect. I'm afraid it is you who is applying ohm's law incorrectly.
In this case, the load is a fixed resistance. When the load resistance is fixed, if the voltage increases, so does the current (amps) and thus, the power (watts). If this load were self-adjusting to always consume a fixed power (watts), then you would be correct. This load is rated based on the applied voltage being 240v. If the voltage is not exactly 240v, then the power consumed is not exactly 7500 watts. Higher voltage into a fixed resistance equals higher current (amps) and higher power (watts).
@@anthonysummy6944 James didn't show the voltage when the load bank was set to 7500 watts but at 7000 it was 243. If we assume the AVR maintained 243 at the 7500 watt setting the actual load is calculated using the power formula P=V^2/R at 7689 watts.
Somewhere down the line the payoff will get better when you can use those spare parts to offset costs on another project.
i need to save up for a generator because where we live if it rains our power goes out just cant afford one at the time but i will get one some day
James, in many of your videos you replace the fuel line and the inline filter and fuel valve. I found the valves but I was looking through your Amazon page and could not find the fuel line and the fuel filters. Would you mind sharing where you get those items from?
Hello James, as I was watching, I was thinking that, should you find another with a rod through the block, you could actually clean it up and make one good one out of the two. If it were me, I would clean it and put it on the shelf for a later save.
Was That a 3/4" drive socket wrench Ratchet on the Rotor Torque down ?
Could the fuel filter being backwards drop the fuel flow enough to contribute to the low power?
I don't think so. There's no check valve or anything in the filters. Being installed backwards mostly means that you can't see when it gets crud in it. It might clog sooner if it did get really crudded up.
The grounding of the engine stop ckt to the generator wiring seems weird. I assume it is connected to the generator ground ckt?
Great stuff james. can i ask, i have a Briggs and Straton storm responder, and i took shield off, getting old to pull, but i noticed a 2 hole mount for a 12v starter and it has the starter ring already installed on the flywheel, its a 2018 5500/8765 , Would you know how to go about getting the parts to make it electric start, i could make a battery tray and wiring, just dont know the starter and any relays and switch i would need, not to may videos out on a conversion. thanks
If a 2018 model, then might be a clone of a Honda GX390. Willing to bet clone parts will fit for a 389cc-420cc engine.
Did you get a new driver? The little Ryobi isn't singing like it used to.
[Edit] I heard your driver singing at the end - power head cap and muffler bracket, etc. So I'm all better now. Whew!
You may get a few good parts of that old motor. James, do you make enough of this to make a living or is this your hobby? I like your new machine a lot easier than the heaters.
That engine looked like it was in some salt water for a time!
I was wondering if they had the cam timed correctly. One tooth off would give poor power. Seen it before.
Jim, at 17:10, is that a split, (or crack) in the middle of that counter balance?
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Jim, some time back you covered the appropriate way to set a governor but I don't recall. I have an old predator. Is it full throttle or no throttle, and the turn the governor all the way to the right? I have a feeling it may be broke, because it seems to run-a-way!
Hey James! Since you have started to measure THD, it makes me wonder... How clean is the power on any of these whole house generators, like the ones Generac cell in the big box stores? Having a whole house generator is a great option for some people. But not if using it would damage your home appliances. Do you have any experience with that, or have any way to test it out?
Multi cylinder engines are cleaner and usually the more expensive generators are cleaner. Have not tested so I could be wrong.
The fuel filter is on back wards?
I hooked the brushes wrong on a gen I was working on(didn’t know what I was doing)and it burnt up the stator. Expensive mistake
You torque everything but the spark plug?
44:32 .....I knew it was a cat video....🤣😂
The shear number of generators I've seen with water damage because someone left it out in the rain for a long while
James, I'm interested in how you handle all the parts and labor going back and fourth between yourself and these other people. Who pays for what? Who has ownership at the end? Do they get sold and the profits split? Enquiring minds want to know. Lol.
👍
How did you get the borescope in the bottom of the engine? Did you go through the oil pressure switch?
Oil fill
I think you should have mentioned that the genset has a 9400 watt surge rating that it failed to meet, the engine is still underpowered.
If you can't get a carb casket is there something else you can use like casket paper and make one yourself?
50:06 you can buy sheets of fiber gasket material at parts stores. I have used the cardboard from a cereal box in a pinch. It's not the space shuttle, it's a small engine.
@@walterbordett2023 What i can't use the stuff on the next rocket to mars...dang it. 🤪😆
James you have run into two engines recently with rust issues because of moisture in the engine. I'd like you to address stationary whole house generators that do a test run every week. They don't really run long enough to get the engine warmed up enough to bake out the moisture. When I check the oil in mine I always find moisture on the dipstick as well as the fill hole. When I changed the oil this fall it came out looking like butterscotch syrup (not metal). Previous to that the installers changed the oil so I never saw what it looked like. Do you know if this is going to cause problems? The last time the generator ran for any length of time was last winter for about 3 hours. I'm wondering if those test runs are doing more damage than good. Thanks for reading this.
You can program the length of time it runs. Right now I have mine run 17 minutes. I know it helps but I haven’t determined if it is running longer or shorter then ideal. I’ll get a better idea when I change the oil. 5 minutes isn’t going to heat the oil enough to drive moisture out and draw more moisture in. So yes running the engine for short periods can be counter productive it it is long enough.
I have gas and diesel sets and neither runs shorter than 30 minutes duringvtest cycles. That is sufficient time to heat the oil and minimize moisture retention. Anything less than that is potentially causing more harm than good. Cheers
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