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cy 23cc engine not starting

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Old 07-08-2013, 12:02 PM
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96roush
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Default cy 23cc engine not starting

I have a Duratrax Firehammer 1/5 scale buggy w/CY 23cc engine! Won't start! Checked everything, new CMR 7H plug gapped at .025 , coil gapped at .017, new gas/oil mix! Found out it needs 92+ octaine, used 87 and haven't changed yet! Checked compression of motor, mine is 45 Lbs, does anyone know what it should be? Also need specs for the coil (ohms)! Seems to be getting fuel, altho it is not 92 octaine as yet! Spark is Blue w/plug grounded to head! Spark is red when using a ignition spark tester! Any suggestions??
Thanx:96roush[&o]
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Old 07-09-2013, 03:33 AM
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Default RE: cy 23cc engine not starting

Fuel octane shouldnt be an issue. I've seen those things run with 50 octane (camp gas). If youre getting spark then fuel might be your issue. You say it seems to be getting fuel but make sure it is. Another thing is compression. Dont quote me on this but I thought I'd read somewhere that good compression on these motors was 99 psi and up. I know someone will chime in so wait a bit.
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Old 07-09-2013, 04:15 AM
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Default RE: cy 23cc engine not starting

Thanx GT100, There is gas inside motor, when I remove muffler and tip upside down gas runs out the exhaust port, maybe a tablespoon at most,maybe flooding? The plug has some gas on it (trace) I am thinking needs new rings, maybe top end rebuild! I just bought this and don't know history! I might just get a new complete engine, don't want to throw more money in this! I am used to working on cars w/compression of 150 plus![&o]
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Old 07-09-2013, 01:58 PM
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Default RE: cy 23cc engine not starting

Can you lift the car by only lifting it by the pullstart handle without yanking the engine?
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Old 07-09-2013, 04:02 PM
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Default RE: cy 23cc engine not starting

Hi Lars From Norway, yes I just tried it and the pull start stays without turning over engine! engine should have plenty of compression, even tho it shows only 45 Lbs with compression tester! I've taken everything apart and double checked gaskets on carb, and all gaps, .017 on coil! I don't know what the coil should test at for ohms, I've checked mine at static w/ohm meter and I get 5.8 ohms is this in spec? I don't know!! I get spark at plug and it is blue, just put 93 octaine gas/oil mix, still no firing up! I'm about ready to get a new engine!! spark plug has trace of gas, but not flooded!!
[&o]
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Old 07-10-2013, 02:57 PM
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Default RE: cy 23cc engine not starting

Try to put some drops of oil directly into the cylinder, this should fill out the gap between the piston and cylinder wall if the compression is too low. Don't know about how many ohms the coil should have, where did you measure this/on what leads? If you tell me i can check on mine later on.
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Old 07-10-2013, 03:48 PM
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Default RE: cy 23cc engine not starting

Hi Lars: I measured from the spark plug wire to the other side of coil (metal )! I just tried spraying starting fluid into carb, nothing, removed spark plug and sprayed starting fluid into cylinder, put plug back in, nothing again! I checked my buddy's compression on his 23cc motor, it was about 100 lbs, so it looks like that's the problem! Starting fluid should have ignited it, but nothing![&o] FRUSTRATING!!!
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Old 07-11-2013, 02:40 AM
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Default RE: cy 23cc engine not starting

Yup, sounds like youre getting blowby. Easiest fix would be a new ring but check the walls on the cylinder first. I usually change the ring every few gallons and have managed to keep motors for years and years. Good thing about gassers is that its so cheap to replace or even upgrade these motors.
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Old 07-11-2013, 04:15 AM
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Default RE: cy 23cc engine not starting

This is about what I am thinking, low compression! I probably will do the top end rebuild, head, piston, etc while i'm at it! Can get parts on ebay!
Thanx guys for all the input, It sure helps!
96roush[8D]
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Old 07-11-2013, 01:57 PM
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Default RE: cy 23cc engine not starting

Sounds much like a compression problem here, yes. But did you try the trick with the drops of oil i was talking about? Just asking
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