confused at why the engine won't fire
#1
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confused at why the engine won't fire
I hope you guys can help with this because i'm really stumped
I just picked up a used fg f1 with a zenoah g260rc1, the car has not been run, in fact its not even finished, its clearly brand new but it has been sat for years.
The seller didn't want me to fuel and start the engine since he was advertising it as brand new never had fuel in it etc but at the time of the purchase I removed the plug and there is a good spark.
so once I got it home I fueled it up with the fuel I use for my BAJA's 91octane mixed 32:1 and nothing not a single splutter, I put fuel directly into the carb and directly into the spark plug hole and nothing.
Things I can confirm: fuel does get to the plug through pulling the starter
the spark plug does fire outside of the motor
there does appear to be compression.
I have stripped and rebuild the motor and there is no doubt its brand new, no signs of damage or corrosion either
both airgaps are correct
I have tried a different plug and tried the coil from one of my baja's (different part number but it does fit in place, probably different timing but I don't know).
I attached an electric drill to the flywheel to try to get it going and nothing is making any difference its completely dead.
thanks
does anybody have any idea what might be happening, i'm usually quite good at this stuff but I can't figure it out
I just picked up a used fg f1 with a zenoah g260rc1, the car has not been run, in fact its not even finished, its clearly brand new but it has been sat for years.
The seller didn't want me to fuel and start the engine since he was advertising it as brand new never had fuel in it etc but at the time of the purchase I removed the plug and there is a good spark.
so once I got it home I fueled it up with the fuel I use for my BAJA's 91octane mixed 32:1 and nothing not a single splutter, I put fuel directly into the carb and directly into the spark plug hole and nothing.
Things I can confirm: fuel does get to the plug through pulling the starter
the spark plug does fire outside of the motor
there does appear to be compression.
I have stripped and rebuild the motor and there is no doubt its brand new, no signs of damage or corrosion either
both airgaps are correct
I have tried a different plug and tried the coil from one of my baja's (different part number but it does fit in place, probably different timing but I don't know).
I attached an electric drill to the flywheel to try to get it going and nothing is making any difference its completely dead.
thanks
does anybody have any idea what might be happening, i'm usually quite good at this stuff but I can't figure it out
#3
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I definitely floded it a few times but I cleared it an tried again and I would have expected it to do something.
iwould assume the gaskets are rubbish because of the age but like you said I'd still expect it to fire and just run badly
iwould assume the gaskets are rubbish because of the age but like you said I'd still expect it to fire and just run badly
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Here is a thread I came across, it's talking about bikes but they're 2 stroke so everything it says to check should apply to your engine
http://motocrossactionmag.com/news/m...oke-wont-start
http://motocrossactionmag.com/news/m...oke-wont-start
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Lol yeah maybe, it will be something and nothing though it always is. I did read somewhere someone has trouble starting one of those engines that bolt to a mountain bike. Almost same problem as you, it turned out his timing was out by 180 degrees. As far as I know the flywheel can only be installed in one position because of the keyway but it might be worth checking out on your engine.
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I checked, its correct so thats not it, I need to get a compression tester adapter to fit these tiny spark plug holes and try that, I don't know if sitting for so long could have affected the ring but i'd be surprised.
Otherwise I might have to send it to horizon for service I suppose
Otherwise I might have to send it to horizon for service I suppose
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What color is the spark. It should be Blue. If not then not enough power is getting to the plug. (BAD COIL) IF you have spark it should at least fire or pop. Make sure the plug cap is attached securely to the wire so the connection is solid from coil wire to the plug. When you took it apart did you check the ring and make sure it isn't cracked or broken? does it move freely in the ring slot in the piston? Also make sure the magnet isn't cracked or broken on the flywheel. also make sure the plug is good. no cracks in the porcelain some times you cant see them.
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The ring looked fine no cracks also no cracks in the coil and it did give a nice clean blue spark. I did however finally get an adapter for my compression tester and found that I only have 60psi so clearly something is wrong, I checked the piston orientation but that is correct I will buy a new ring and see if that solves it. I don't know if a ring can degrade over time but i'd be surprised if thats the case. its all very weird.
thanks
thanks
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Check the exhaust, insects could have built a nest in there & restricted/plugged up the pipe. That will keep it from firing & affect compression readings. Unbolt the header/flange & check compression, if it comes up clean the pipe out. Wasps/dirt daubers are famous for this I have also seen spark plugs that will not fire under compression, but appear fine outside the cylinder......but that wouldn't affect compression.
Last edited by moparbarn; 08-24-2015 at 04:51 AM. Reason: added info
#11
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Great information thank you for that but alas no luck, I thought it would be a weak spark not firing under compression but then I found that I don't have any so that negates that.
I just spoke to ddm racing, really nice helpful guys and they said that the ring and base gasket have a large effect on compression, I ordered their full top end rebuild kit for my car for good measure but I will add it piece by piece so I can inform you guys of the outcome.
thanks
Kim
I just spoke to ddm racing, really nice helpful guys and they said that the ring and base gasket have a large effect on compression, I ordered their full top end rebuild kit for my car for good measure but I will add it piece by piece so I can inform you guys of the outcome.
thanks
Kim
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Hey buddy a couple of other things you need to check is the needle settings on your carb as they could be out , all so does the car have a pico kill switch installed if it does remove it and see if that makes a difference as it may be faulty . All so its is possible that the carb is faulty if you have a spare try that as well and just because the guy said it was new does'nt mean it is , it seems a bit odd that he wouldnt let you start it not saying he was dodgy just saying it was a bit odd , hope this helps before you rebuild the motor cheers.