High Compression - Impossible to Start Generac Generator
ฝัง
- เผยแพร่เมื่อ 6 ก.พ. 2025
- My friend Jason sold one of his generators to a contractor. The contractor offered up his old Generac GP7500e to Jason at no cost. No information was provided about its run condition. I assume it has high hours and no longer runs. I turned the engine over and it sounds good, but the compression is really high making it difficult if not impossible to start. It this a parts machine or will it run again?
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. Recently I have been using Simple Green PRO HD with good results.
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#Generac #GeneratorRepair #Generator #SmallEngineRepair #SmallEngine #DIY #Fixed #Troubleshooting #howto
Adjust Valves, Alternator, Broken Compression Release, Carburetor Cleaning, Clean Slip Rings, Compression Test, Decompression System, Dirty Carb, Engine Rebuild, Fixed, Generator, Hard To Start, Hertz, High Compression, How To, How-To, Insulation Test, Load Test, NGK BPR5ES, Old Fuel, Open Engine, Partial Choke, Remove Rotor, Remove Stator, Repair, Resistance Test, Small Engine, Stalls, Struggles to Crank, Stuck Compression Release, Surging, Troubleshooting, Valve Lash
Who else watches the whole video without skipping a bit 😊
Your videos are very relaxing, educational and very well explained, my favorite channel 👌
I watch everyone i have learned so much from James the guy is a master.
Can't skip through any of James videos 😊
I skip through
But im also a mechanic by trade so theres a lot i can skip without missing out
I cherish every minute of his videos. They keep me sane at age 82 with a disintegrating body.
The key isn't skipping parts of the video. It is however, watching at 2x playback speed which is very doable with his videos.
James im 85 years i have the knowledge and all the tools you are using. I will give all the tools to a person who works like you and i used to do.
I'm still learning from this man and I'm 60 years old and I still don't have all the stuff that he's got but I'm still working on him I'm still learning what he does he does things a little bit different than I do
That's a great gesture sir... I hope you find a deserving person..
Good man!
You are beyond reproach. 😊
James..???
When you swapped carbs.. possible the main jet was not the same and or may have been smaller than the original carb may have been...you were saying that the carb looked like it had been changed ....main jet may not have been large enough for the 7500 watt pull????
I commented a few months back about the length of your vids. I now realize IF I had one of these generators, there is no better video to follow to repair it. This is the best small engine repair channel on YT.
Well, more specifically generators as that's probably 80-90 % of his content. If you want fairly concise but informative videos I would say DonyBoy73 or Steve's Small Engine Saloon. James is like Mustie1 where you can sit and watch the videos for an hour or more but for diagnostic purposes James is pretty good all the way. Of course for handheld engines, Chickanic is pretty good and for advice as well and Taryl is informative in a Red Green style, just without duct tape.
Regarding length: this is the first I've watched. Often I turn up the playback speed on videos I actually don't have time to watch. This video is perfectly understandable at 2X.
Mr. Condon you remind of a caring father speaking to his children with a calm patience & profound understanding of the subject at hand ❤ 😊 Your posts are always informative & well my time 😊
I picked up my late Father-in-law's PowerStroke 6800 Watt unit with the Honda GX390 engine (NOT a clone!) The generator counter had....22 hours on it! The unit sat in his shed and got a lot of crud on it, but thankfully no mouse house. Cleaned up nicely. I had to remove OLD fuel. Changed the oil, removed the carb and gave it a deep cleaning. The engine started on first pull and runs great. Why? Because I watch James Condon videos and I did EXACTLY what he does. Thank you for the great work you do, Jim.
Some guys watch golf to relax, I watch James. Love it.
Thank you for watching!
No matter how many generators you work on there is always one that shows you something you haven't seen.
The time-lapse of the ultrasonic carb cleaning is always extremely satisfying to watch. Gourmet.
Coffee,check. Egg Scramble, check. James Condon Thursday morning video, check. All systems go for a great day!
Not sure why this video was presented to me BUT, absolutely amazed watching you tear the engine apart - systematically addressing all the components and stating their purpose.
I learned more watching you in this video then the few small engine repair books I have sitting on the shelf which lack the context that you provided.
There is nothing finer than sitting back watching an expert do their thing … thanks for the invaluable education this video provides …
At 32:26
Fuel line....
Good thing you got that on camera! Nobody would have believed you if you hadn't....
At 48:09
"....who would have thought a piece of plastic would have done that...."
Definitely another thing that you needed captured for posterity!!
These really are beautiful machines. I have a 15 year old Husky 3750 watt generator that never had any service and ran for 3 days straight powering my parent’s house during hurricane Sandy 12 years ago. Inspired by your videos I decided to give it a chance at some more life and did a full service. It had about 300 ml of oil in the engine…factory oil that had never been changed. Carburetor was a mess. After the JC treatment it runs like a champ again. Thanks so much for the education and inspiration!
The one thing I enjoy most about your videos is that no matter how much I think I know about mechanics, engines, and how things work... I ALWAYS learn something new from you!! Especially the small little details that most either overlook or ignore. In my experience, those are the ones that either make or break you. Yours rapidly became my favorite channel. Thank you for your detail to the little tubes things.
Little things
I use to do the same tweaking but with humans on ventilators. It was truly a learning experience. 40 years I did that. Now at 75, I am just enjoying watching people like you tweak things. I love the science behind it all. A great deal of what is going on with machines like that one was all brought to us by a immigrant named Tesla! 🤔💕👍
A James Condon video is not complete unless it includes a trip to the paint booth. Well done.
Paint does not survive long in his area,that motor had silver spray paint all over it already,
I own a couple of Honda's. I never understood why they bother with a dipstick. We have all been taught that if there is oil on the hash marks, were good. This isn't true with these. Great save on this one.
James, watching you work is like watching poetry in motion. You keep a clean work area, you are thorough , and your diagnosis is always spot on. I’ve learned a lot from viewing your content, so thank you for sharing!
I really Enjoyed Learning from you, I’m 54 and anyone with a little Knowledge, Could Learn a lot from you. Very well done. Thank you
Glad to help
Thanks James-it's channels/videos like yours that *will* make cable tv obsolete.
Wow, thanks
@@jcondon1 // James; I just went back and re-watched this, namely because of your response. During the video I thought "I think it's true" especially when it involves an item(s) that are rescued from a landfill, or those people design/build themselves. Fact is, I regularly see comments stating "This is way better than anything on tv" i.e., the "how to/mechanical" related videos e.g., repair, rescue/restore, etc. Those comments and even some here, reflect the fact that people are starting to choose to watch videos like the ones listed here [you are helping someone]. 👍 God bless.
Excellent video, professor. Imagine that...broken dipstick. Another genset saved from the junk pile.
Man! Just a side-note: Amazon boxes are the best. Used to lay equipment on when servicing it. I use them to lay on when performing maintenance under my vehicles because I have a gravel driveway.
i got the honeywel 7500 and it powers my house.. your videos have saved me soo much in parts and maintenance repairs/ i wish u were my neighbor here in MidCoast maine, Small engie repairs guys are dissapaering
I have always wanted to retire to Maine.
Howdy neighbor. Another MidCoast Mainer who enjoys James' must watch weekly video.
What heat do you set the sonic cleaner at.for cleaning your carbs
@@jcondon1 Come on up! I retired here from MA in 2016. Great place to live. Question: I knew of a Condon family in Dawchestah, MA. Are you related?
@@williamwallace8994 Waldo County- Swan Lake.. retired and bult after 20 yrs on Active Duty USMC..
This is an awesome rescue . Amazing how a broken off dipstick is what almost sent the generator to scrap yard.
And that slip ring polishing with scotch pad is so satisfying 😄
And that insulation on terminal that go too far could definitely be a problem
How many roofing jobs has that generator seen? 😊
Love watching your methodical approach to repair.
Great work.. Please consider buying a gallon of Omega clean.. I promise everything you run through the ultrasonic tank will come out cleaner.
Another beautiful rescue, James. That bit about the contaminant being a part of the dipstick is almost baffling. The only way I can see that happening is outright carelessness on the part of someone operating that generator, and it reminds me of something which happened quite a few years back.
A large (15KW iirc) generator had been loaned by a church group to a Boy Scouts group, but came back not working correctly. I was asked to have a look at it. I found that it started but would only idle after starting, which was baffling to me at the time. It took me a while and a few tries before I finally realised that there was "something screwy" about the throttle control. It looked almost... backwards. After further investigation, I realised that it looked to have been pushed all the way past the full throttle position and right around to the idle position again, and was jammed there by a metal bar which should have fouled it on the way through and prevented that from happening. With a lot of effort, I managed to force the idle control back past the bar and when I started the engine again, the generator came up to speed and regulated correctly. So it was fairly obvious that someone had abused the generator and maybe even deliberately fiddled around with it in a way which wouldn't be too obvious and which they thought would be very hard to discover. I'm pleased that it proved not too difficult for me to discover and fix. 😄 I still don't know how it actually happened, and I'm glad that it wasn't my job to find out.
My little generator repair seems to be finished (need to double-check when I start it next time). I got it running, I confirmed that it would hold the right speed supplying 1000 Watts to a heater (it's rated for 1500 Watts maximum continuous load), and with the help of a frequency analysis app on my phone, I set the speed as close to correct as I could. The speed is supposed to be 3000 rpm for my country's 50Hz power supply, so since it's a 4-stroke engine which fires once every 2 rotations, I set it so that the frequency the analyser could "hear" from the exhaust was a tad over 1500Hz. I'll give it a final test along with my regular monthly "maintenance run" of the other two generators I have, then decide if it's worth selling or not. I'd guess I'll only get back about what I've put into repairing it. Maybe a bit more if I'm lucky.
Awesome. Those frequency apps come in real handy.
My guess on power loss would be on the intake side since the carburetor and airfilter/airbox wasn't the original spec. Could of course just be a simple thing like the main jet being off and you'd need to use a wide band exhaust sensor to see that the mixture is right. The sound was a bit like it was running slightly too lean.
Perfect timing for me. I have an engine that is showing excessively high compression. This gives me at least a starting point. Thanks...
Without the video no one will believe you about the broken dipstick! Great job as usual.
I suspected the filler cap the second I saw the orange color of the fragment on the cam, so much so that I rewound to the oil change to look at it. Then I was waiting for you to find the dipstick.👍
I like the fact that you don't skip details when you get towards the end. So many cut out details as they get close to the end and if your trying to do something the way they do it doesn't work. I really enjoy your channel James. Keep it up.
James, was just given a free generator that was completely submerged in salt water. Started poking around TH-cam to get some tips to restore. Came across your channel and it has been amazing. Learning so much from your videos. Thank you for taking the time to explain everything, from minor issues that a beginner would not know, to more complicated explanations that would benefit those more experienced. You are the best I've come across so far. Liked and subscribed! Can't thank you enough.
I once had the opposite problem on a Subaru-Robin flathead engine. The compression release would not disengage which meant the engine would not run properly. The oil in that engine was extremely black and sticky and full of sludge.
After changing the oil the problem still did not go away but the trick was to spin the engine at a high speed using a drill and socket on the flywheel nut. That made enough centrifugal force to force the weight outwards and I guess the new oil did its thing and everything worked fine after that.
James, I've watched many of your videos repairing generators and I have often had the thought that maybe star washers ought to be installed on the threaded electrical terminals to ensure the best possible connections. It would be a small thing with huge results, in my opinion.
Hi James, I've watched maybe all your videos and enjoy them all. You might make mention of the screwdriver that you use to remove the main jet / emulsion tube for the benefit of those watching your videos. That's a 'special' ground screwdriver made for the purpose. Some new viewers may not realize that and try to use a regular screwdriver which will bugger up the jet for sure!
I should, but the set I use is no longer available. Here is a link on it th-cam.com/video/jN5c76XCQFo/w-d-xo.htmlsi=Pl6GB_xrtNQlNKsd
@@jcondon1 Great reference video! I enjoy Donyboy's videos as well. Thanks!
My FiL left me one, and I don’t know what it was, until James was using it and I made the connection.
‘WOW!’ James has the same screwed up screwdriver as the one Dad left!’
Duh.
‘Today I learned…’
I worked on a friend's WGen9500df. The electric start wouldn't work and the pull cord was broken. He had bought a new battery, expecting that was the problem.
The underlying cause was a failed compression release on the camshaft. The high compression combined with the wireless remote electric start repeatedly cranked the engine until the starter burnt out. The broken cord was from him trying to pull start it.
The starter rotor wasn't just a little toasted, it was fully charred with a strong smell.
In my case the compression release wasn't simply jammed. It was horribly mangled, with broken pieces beating up the oil level float frame, breaking the tip of the oil splash fin, and leaving plenty of gouges elsewhere.
Every part that needed to be replaced was out of stock from Westinghouse, while most other parts were listed as available. I suspect that this wasn't a one-off failure.
These Thursday morning releases just make my day! Thank you sir, another "revival" gone beautifully!
I was wondering about the light, then you answered that question. Although that wasn’t the issue. Watching from Panama City Florida,USA. 🇺🇸🦅 !
what i was taught in gen. repair school is NOT to exceed 80% of total load of the MAX cap. of the gen. set. so far its worked for me for years. nice save on this gen. set !
That gives capacity for surge at load startup.
@@robertpeters9438you don't have to start all the subloads at the same time. Start the largest load first then smaller loads....
Hey boss, noted at about 1:02:52, it looked like the pilot jet didn't fully seat. It looked like the o-ring twisted and then sprung the jet back up once pressure was removed.
I love watching James repair all the things he brings back to life. I understand what he is doing but get stopped when he uses his torque wrench. A repair manual would tell me what the setting should be. I'd buy a manual, but I get the same thing. I'm informed I must be an authorized service center to buy one. Do you have any help commenters?
Just rolling through TH-cam and I found your video well done. I watched the whole thing lol
James, Love watching you. One thing I noticed is when I work on stuff that is stuck, bolts, nuts etc. Apply whatever spray you like best, but I always let it soak. Makes a world of difference. The PTO you had stuck on the Cubcadet was one example.
Anyway, keep the videos coming. I still have a problem with my Cubcadet kz1042kw, hydro transmission, hangs in forward. Very annoting, reverse is ok.
Sam
Letting it soak is the way to go. Unfortunately, I have a schedule to keep so usually rush though that part. It still helps spin the nut or bolt out once moving.
El mejor canal de TH-cam, tu no lo buscaste TH-cam te lo recomendó.. Dios te bendiga James..
Great video! Looks like a new machine, not a throwaway! I thought the oil plug looked funny when you checked the oil. Your videos are so good I could almost see the plastic dipstick was broken. Enjoyed the video, keep it up!
I know this is not your usual type of video, but I would love to see you do a "generator buyer's guide" kind of video. You must have tremendous knowledge and experience across a wide range of generators and you must have some opinions of what's good and what isn't. Recommendations for new and used generators across different categories (like portable, camping, home backup, etc) would be super helpful, as well as what to avoid.
Think about it: With 20/20 hindsight, draining the oil and doing a borescope inspection, pulling out those 2 pieces, it could have been running in 20 minutes.
Thing is, you put it through the paint shop, upgraded the carb, reset the valves.
Sure. It gives up a little performance, but that thing is rock solid. It’s better than new.
Well done.
I beg to differ. The piece of the plastic dip stick was lodged underneath the compression relief slide, and was removed by working the slide back and forth. You can't do that with a bore scope.
Thank you for showing all of this. I have the exact same unit and I think I'll be removing the old brittle dipstick for fear of it breaking off ! Maybe ill get one of those metal magnet dipsticks / oil fill caps.
Erase that FIVE and change it to a ZERO... Voil`a 7000 watt generator. You do admirable work and put together an enjoyable video to boot. Much appreciated..
It's so fun to watch a professional work his trade! Thank you!
Hi James. Not related specifically to this video but wanted to thank you for a couple of past ones I went back and rewatched. Have an old mantis tiller that didn’t run well and had the confidence to order a Hipa carb kit for $14 to try and fix it. Led me to believe I had a crank case leak like your chainsaw video, however, I went back and rewatched your mantis one from about a year I ago before I pulled the trigger on a gasket and seal kit. Was perfect because I had totally missed adjusting the low carb. I did that today and it works perfectly after some additional carb tuning! Thanks so much for all the videos!
I would rather watch your videos over any mystery program on TV. Ah-ha the dip stick killed the generator! Great detective work and you revived the victim to go back to work. Sure cleaned up nice as well.
Good video, very informative, NICE clean job. Personally i would have used some liquid rust inhibitor on the Stator/Coil of the ignition system and reset the gap, but thats just me. Well done!
Saved another one from the scrap pile great job keep them coming
With that generator being an ex contractor machine and the total hours and prior maintenance unknown the hp loss could be from normal engine wear. A new ring job and valve lapping could restore it to as new. But i agree its not worth the effort and expense. Close enough !! Great job, James !
Was thinking the same.
I've come to think of your Thursday morning upload as the start of the weekend. Nice!
Great video!
👌👌👍👍 Nice work! Oddly satisfying and calming to watch work being done in an orderly manner. Maybe the 7500 watts is just the "surge load" as opposed to the running load?
James all the tools are into new hands . The only things i keep are my hands and my brains .Bye to a goodd mecanic. Jan.
Interesting fix for an interesting problem
Tip for rotors that were not threaded we in the engineering lab used a lead hammer to smack the crap out of rotor it would release
If only you had been my Power Mechanics teacher in high school. I coulda been a contender!
I recently had to remove a GP5500 generator head and didn't have a gear puller for the stator. I ended up using 2 large reversible trigger clamp and pushed the stator off the crank cover. worked surprisingly well.
I like to just disassemble completely and clean all parts examine them clean ,paint and prep. I put all arts in a cardboard box and bolts 🔩 then i assemble the unit and it looks and runs like new
In my opinion, aesthetics are nearly as important as functionality when selling something 2nd hand, and the time you take sprucing them up is well worth it.
In comparison to when you pulled the cam, you installed it aligned to the crank with the wring notch. When you pulled it apart it was aligned with the dot closer to the center of the cam gear, installation showed you aligned it with the dot further from the center (one tooth off)
Regarding the last 300 watts. Did you check to see if the throttle plate was fully open when you were calling for max power? I can imagine a situation where the linkages prevent you from fully opening the throttle.
You videos are a joy to watch. You are respectful of the viewer. We can always see what you are working on. The camera is always on a tripod. The audio is clear. The boring or repetitious parts are either edited out or go at high speed. You like a tidy workspace.
Thank you!
Heat works magic on rusty bolts... better than any canned product. I always keep my propane torch in the garage with me when working on the car.
I have seen many stuck decompression weights and have never conclusively seen the actual cause. this is a bonus! I always felt odd putting it back together and never knowing. I never got a call back for it. So I assume cleaning them, fixed them. :-) If I needed I genset and lived in your area, I would easily pay more than market value for one of yours. I would never underestimate the value you put into these generators to make them the best!
I usually replace the cam if I cannot find a cause and know it is fixed. Usually it’s not obvious like this one was.
Thanks for sharing James, another great video. Thursday morning at 7am has become my weekly ritual to watch your videos. 👍🇨🇦
That was a good one Congrats on a good fix. Little hunk of plastic. I had something similar once. I rewired an AC condensing unit and also changed the compressor. I neatened up the wires with plastic wire ties. Started it up and charged the system and it ran great...for two or three days. Then the compressor went up in smoke. Turned out a piece of the plastic wire ty fell down inside the motor contactor relay
Fascinating! Well done.
Given the crusty exterior look I am surprised this machine didn't fight you more. Good lesson today on how the smallest bit of debris in the wrong place can cause foreign object damage (FOD). Good video James.
Great save James even at 7k, watching late wife not feeling well and better that I'm not on TH-cam.
Keep posting as everytime I learn something new.
Tks Michael
I have been using those Autozone spark plug gap tools for years, and I never thought to use the hole to widen the gap. I guess you learn something new every day, lol.
It is time to get a blast cabinet Mr Condon.
I have fixed a generator for a friend lucky for him it just needed a coil now it runs great
You are inspiring me I've got a free champion 4875 from Craigslist? have started very preliminary steps. Thank you
Awesome video+presentation well done mate! thank you for sharing your knowledge 🙏🏻
Welcome back!
Easy one today James,looks like that bit of plastic came from the oil cap
Great video James. See you next week.
Another Thursday generator gets saved,very enjoyable video
Wow a great video done by a pro, love your work style, definitely not a greenhorn or hack moose destroying everything in sight.
A rarity these days and mucho respect from this retired fleet tech
Thanks 👍
Excellent instructional video, thanks.
wtf just a little piece from the oil cap can do this? amazed and terrified for that labor. good work.
Thanks for this series of videos I'm just starting to rebuild this same motor on a walk behind weedeater so this was very helpful the only problem I have is getting parts for it here in New Zealand can you give me advice on where to look plz ?
Nice video thanks.
A lot of my Honda engines seem to need a tiny bit of choke to run nice. Makes me wonder if they were designed to run at ‘American’ altitudes ie a bit higher than sea level.
I took a tiny jet drill and increased the main jet size a smidge, it seems to make them run a bit better and not hunt. They have done this from new.
Thanks
Not sure!
Jason seems like someone you’ve mentioned before, like he’s a regular contributor of machines in need of diagnosis and treatment by Dr. Condon
James, if you keep loosing a .001" or 2 when adjusting the valves, start with a larger sized feeler gauge.
Great job James
Nice job Jim! Thanks!
Nicely done James. It never gets old.😊
Great job
Great troubleshooting James 😊
I watch these beginning to end. I enjoy the problem solving style that James has. Its hard to find someone who knows what theyre doing and cares about their work. Good Job James, Good Job!
Good find
Very good video James. Thank you for the finer points of editing, it made it flow smoothly from a viewer perspective. Just a couple things I'd like to mention. 1). The carb you replaced may not be matched or manufactured to the spec's needed for that engine. So possibly there is an A/F ratio issue at max demand. 2). There are feeler guages w/ a step on them to be used as a "Go-No-Go" quick measure. And finally, 3). I own a 1970 Montgomery Wards lawn tractor (Gilson built) that has a 14 hp Briggs engine that some how my son put the engine oil dipstick in wrong and something chewed the end of it off. The dipstick tube is rigidly attached and sticks up above the main engine block making the dipstick about 9 inches long. The dipstick is metal so there are metal shavings and bits all over internally. That lawn tractor was very well built and is still on the job. Gilson designed it very robustly. Hydrostatic drive makes the rototiller work perfectly. 42" mower deck & 46" snow plow are hydraulic lift. A fine example of "proudly made in The U.S.A." FB James, tnx. ben/ michigan
Defiantly could be jetting. The engine was holding well at 7200 watts at about 59.5 hertz.
Thanks again you must have had a teacher that loved you like a son.
I watched the whole video. Great find.
best blog I've seen in a long time coming from your channel. I like longer bogs and keep me interested longer and you taught me something
Hey James, I just wanted to let you know that I figured it out.
This engine has a vertical shaft, and under the pulley, the shaft is connected with a pin that is designed to shear in half, in the event the mower hits something hard
Anyway, the pin had separated in half, causing bad timing.
Once replaced, it pulled easily, and started right up.
I've only found one other video, of a Brigs and Stratton with a vertical shaft, and high compression, because of a broken pin.