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Hey everyone I have a 250 cc inline twin quad 253fmm-c, it wont start.
I have
cleaned the carb 3 times
fresh fuel
new plugs
checked valve timing and valve clearance, both right
compression test 160 in both cylinders
checked for spark , good spark in both
Does anyone have any ideas, thanks
Airfilter?
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A little blast of starter fluid might be helpful to see if you're actually getting a strong enough spark. WD40 works in a pinch.
Air filter is clean and I have tried it on and off thanks
I haven't tried starter fluid yet but I will give it go, the engine tries to go but won't Rev at all
I put the carb through an ultrasonic bath but still no go, im out of ideas other than replacing all the electrics
Did you try playing with the air-fuel mixture screw on the carb? Is the plug wet after you crank it for a while?
Yes I have mucked around with it, what would you recommend a good starting point 1, 1/4 turns from fully wound in?
Any former activity on inlet valves, e.g. adjustment? Maybe nearly no opening?
Was camshaft out? Maybe timing is wrong. Happens easily by just missing one tooth or use the wrong marker on the fly wheel.
I assume its somehow a timing problem.
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Oh, and check the connection between carb and cylinder. When u have air leakage there then u can play on the carb for ages
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you really should try the starter fluid first, ive had non working carbs entirely bypassed for a brief time just fueling with starter fluid...
when your engine starts anyway then you know for sure its just a mix/delivery problem
Hey guys thanks for all of your help, after testing the ignition timing with a timing light I could see that the spark was intermittent so I got another cdi and it started instantly and idled like a dream . thanks