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nickskethisniks Guru Joined: 17/10/2017 Location: BelgiumPosts: 458
Posted: 09:11am 25 Jan 2023
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Just when I had it all together my inverter stopped working... this is the unit (for reference): https://www.youtube.com/watch?v=w3L1rf4lVjY
The unit is bought in december 2019 and now has about 900 working hours.
A few days ago I had the inverter running all day with a 1700W load (eltek psu). No problems, 10h with a refill. I let it run till empty.
Next day I refill the tank and tried to start it, but nothing...
I checked and cleaned the carburator (it was clean) and spark plug (tried 2 new ones), made sure there was a spark, no problem there.
I don't know what I could do next to check. Elektric or with the pull cord made no difference for starting the engine.
I also checked the stepper motors, the choke or inlet servo worked and blocked the entrance for maximum gasoline intake. The other for the rpm/speed control did not move but I tried all sorts of positions.
Although there are sparks, I suspect the ignition coil to be bad, the primary was about 1R (difficult to measure that low) and the secondary was 15K, if I explore google it should read more like 10K? So the coil might be bad, it might not be powerfull enough anymore to start the engine.
I think I don't here explosion so the gas is not igniting?
It's just freezing point (0-2°C) over here, I noticed the inverter needs more warming up time before I hit the switch. I could try to heat up the motor block to see if it's making a difference.
So I was searching for a new ignition coil but nothing found on that serial number. I ordered a new coil from aliexpress for a different generator. https://nl.aliexpress.com/item/4000326852242.html?spm=a2g0o.order_list.order_list_main.5.21ef79d2gM5DgT&gatewayAdapt=glo2nld
This should be capable to start a 200cc motor, anyone that can educate me on the differences between all different kinds of coils? They all look the same to me, what can there be so different, besides the inductance?
Any tips for further examination? I can use some help.
I now have a small generator running that's making more noise then power.... So I will need a new solution (generator) if I can't make it work again. I want to stay off grid, a stirling engine that I can heat with wood looks ideal or biogas or h2 generation in summer and consumption in winter... Edited 2023-01-25 19:26 by nickskethisniks
phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135
Posted: 11:35am 25 Jan 2023
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Without before and after values ignition coil resistance doesn't tell you much, they can be 5k to 25k secondary and .5R to 5R primary. If you can get a spark length of 5mm or more at cranking speed for a non-CDI system it is probably ok. 10mm or more for a CDI.
On small engines sometimes, if it happens to stop with a valve open (usually exhaust) it will stick there so you have no compression. When you try to pull start can you feel the compression stroke?
I have a small generator that won't start in cold weather unless I use AeroStart ether spray. We have a local brand called Start Ya Bastard! that works quite well.
nickskethisniks Guru Joined: 17/10/2017 Location: BelgiumPosts: 458
Posted: 05:06pm 25 Jan 2023
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ok, thanks for the input!
For test, I tried to heat up the engine with a heatgun, trying not to blow my self up :). I had the feeling it gave some improvement, but no running engine.
I think I feel the compression stage when trying the pull start, how could I inspect the open valve, just looking?
I will try to source that kind of spray, I saw that being used in some youtube video's.
phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135
Posted: 09:32pm 25 Jan 2023
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"how could I inspect the open valve, just looking?"
With the rocker cover removed (photo 2) crank the engine. You should see the valve stems (inside the springs) move in and out.
While you are waiting for the spray try squirting a little petrol into the carburetor and see if that works. Even WD40 may work if it is almost firing, but just needs a little extra flammable vapor.
greybeard Senior Member Joined: 04/01/2010 Location: AustraliaPosts: 161
Posted: 11:38pm 25 Jan 2023
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Spark, fuel or compression. Need all three. If spark ok, (see posts above) and can feel some compression then that leaves fuel. Given that you ran the tank dry and now it won't start, that's where I'd start looking further. Maybe some crap got sucked into the fuel system when the tank ran dry, air lock, (embarrassed to ask but ) fuel turned on? kill switch is probably ok if you can see spark. If you've tried to start it and then pull spark plugs are they damp from fuel? if not I'd suspect fuel problem. What I'm saying is I suspect fuel issue from what you have said and diagnosed above. good luck.
nickskethisniks Guru Joined: 17/10/2017 Location: BelgiumPosts: 458
Posted: 08:49am 26 Jan 2023
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Thanks for all the suggestions, I'm a noob with ICE ...
So I might found a problem, I checked the valves again during start up:
Something is stuck: sometimes it's normal but mostly not, so I assume one of the valves is not working correctly this way... Can I assume this can be a major failure since it's not coming up?
I will try to upload a video.
Edit:
Ok, so I tried to move it a little bit by a soft hammer, but it's not moving fluently, I can move the small piston but it's going smoothly like the other one, the spring can't move the small piston by it's own.
What can/should I do next? Is it a lost cause? Taking it all apart and then see further? Edited 2023-01-26 19:28 by nickskethisniks
johnmc Senior Member Joined: 21/01/2011 Location: AustraliaPosts: 282
Posted: 09:39am 26 Jan 2023
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Good day All The engine looks like a Honda or a Honda copy. These motors when cold, will only start with choke FULL on. The carburetor main jet will some times block, also the main jet air bleed tube will some times block the fine air bleed holes. There is some good diy servicing information on utube. I usually spray some lpg gas into the air intake at the carby to check if the engine will fire. Cheers johnjohnmc
Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022
Posted: 10:09am 26 Jan 2023
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Looks like a stuck exhaust valve, usually they can get sticky and sometimes free up if wound over very fast with a fair bit of oil poured down the plug hole, but a really stuck valve could be a different story. A good soak in oil might help free it up, unless there is some other damage, hopefully the valve seat is not out of place, if it has an insert.Cheers Aaron Off The Grid
nickskethisniks Guru Joined: 17/10/2017 Location: BelgiumPosts: 458
Posted: 10:26am 26 Jan 2023
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Here is the vid: https://youtube.com/shorts/qXAswdG0PhQ?feature=share
phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135
Posted: 11:54am 26 Jan 2023
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The engine looks like a Loncin Industries (China) version of a Honda.
As Revlac wrote if the valve stem is binding in the valve guide it can be freed up with some lubricant (eg WD40 or similar) and working the valve back and forth or rotating it. Easier to do if you remove the rocker but when re-assembling the clearance between the rocker and valve must be set the same as the other valve. You will need a feeler gauge to measure it.
If you can push the valve in but it doesn't return all the way, stopping abruptly 4 mm or more short then the valve seat insert has probably come out of the head. (Note 1) Repair will require removing the head, getting it machined and a new seat insert fitted.
Note 1 Aluminium is too soft for a valve seat so a ring of cast iron or steel is inserted into the head. If it comes out it drops and hangs on the valve stem, preventing the spring pulling the valve all the way back. Edited 2023-01-26 22:13 by phil99
nickskethisniks Guru Joined: 17/10/2017 Location: BelgiumPosts: 458
Posted: 02:20pm 26 Jan 2023
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Thanks guys, the wd40 everywhere trick for lubricating the valve cylinders worked. I've got the unit working again at idle, I Will crank up the power this evening.
Now let's find out how long? Sure this Will happen again I guess?
How can I avoid it? So running the tank empty is a bad idea? Better to shut it of by the switch?
Edit, I've got this running at 1500W load at the moment, I hope it can last this winter. Days are getting longer so as the solar production, fingers crossed.
It would be neat to run this unit on gas as well, or even better running it on biogas from a home digester or wood gassifier. Ok for now, stresslevel is going down, time to finish other projects to keep the wife happy . Edited 2023-01-27 01:46 by nickskethisniks
phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135
Posted: 10:01pm 26 Jan 2023
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"How can I avoid it? So running the tank empty is a bad idea? Better to shut it of by the switch?
This is just speculation. 1) As it was running out of fuel there would have been a lot of extra oxygen in the exhaust producing oxides of nitrogen. 2) When the engine stopped the exhaust valve was open. 3) As the engine cooled the water vapour (note 1) in the exhaust condensed and reacted with the oxides of nitrogen producing droplets of acid that, with the remaining oxygen rusted the valve stem. 4) When you tried to start the engine the rust prevented the valve stem sliding back through the valve guide. 5) No compression, no start.
Note 1 When a hydrocarbon burns in oxygen the carbon produces CO2 and the hydrogen produces H2O vapour.
CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 2075
Posted: 02:05pm 09 Feb 2023
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agree. if the spring is OK, might be the valve seat is cracked - when they crack, they tend to close up diameter a bit and can grip the valve stem.
I think whatever, you're gonna be taking the head off for a closer look - at least then you'll now for certain what the condition is like
my 2p
EDIT: oh. glad you got it working Edited 2023-02-10 00:08 by CaptainBoing
Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022
Posted: 08:42am 12 Feb 2023
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It will run ok on gas, you should have some upper cylinder lube when running gas of any type, I have used LPG with an oil drip (was already connected in the Subaru engine bay), there are kits around that can be setup for any engine, although I have never bought one, it wouldn't be difficult to rig one up.
Its Always good to have a few alternative energy sources around as access to fuel and power can be lost at any time, I have run Woodgass for a few years, not the usual wood gassifier type, this one made gas and charcoal, the gas was cleaned filtered and compressed into gas cylinders (need a lot of them) and ready for use as needed, with a gas carby adjusted correctly it was just easy to turn the tap on the regulator and start the engine same as you would with petrol. It may not be worth the effort ATM, but when The SHTF it might be. Another worthy option is Flash Steam, all the waist heat can be used to heat the house if in a could climate area, type of generator to be used is another story.
I sometimes have a load of spoiled fruit and vegetables, one day I would like to try and make some alcohol out of it and run an old engine, would be better to use one of those water filters on the fuel line.Cheers Aaron Off The Grid
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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) fuel turned on? kill switch is probably ok if you can see spark.
