• Problems cranking

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 #12890  by Jeffrosoupy
 Mon Oct 08, 2018 6:28 pm
So recently I wanted to get back on my gy6 project, so last year I installed a big bore kit 58.5 set timing everything finished it fired up and drove it around all night. Went out the next morning wouldn’t crank, cranks over alittle then stops. Figured out if I take out the spark plug cranks fine once I put in the spark plug it seems like it has to much compression. Starter new, battery’s new grounds are all good. I thought maybe timing is off so I redid timing today and adjusted the valve lash and still the same? Wondering if anyone has any ideals what it could be and also took it all apart again today and the piston rings seem fine and so does the cylinder.
 #12891  by Travis @ Buggy Depot
 Mon Oct 08, 2018 7:03 pm
Most likely overlooked cleaning and oiling the cylinder bore and piston and rings immediately before assembly. Causes exactly what you're describing and is overlooked on many first-time builds.

Feels like the starter doesn't have enough power to get past compression, but it's really the added resistance from a layer of funk from the factory.
 #12894  by Jeffrosoupy
 Mon Oct 08, 2018 11:35 pm
Yes it does feels like the starter doesn’t have enough power, but starter is brand new if I crank it just spots at combustion n if I bump it again will spin, but if I keep the key turned doesn’t constantly crank gets to a certain spot and stops. So I should pull it apart and deglaze the cylinder wall with a hone your saying.
 #12921  by TexasMech
 Tue Oct 16, 2018 11:16 am
Not necessarily deglazing as much as cleaning all the cylinder walls, piston, rings and inside the oil ring grooves. There’s usually a coating of stuff leftover that is probably burned on there now, you’ll just need to clean it all off, oil everything and reassemble
 #12925  by Jeffrosoupy
 Tue Oct 16, 2018 11:42 am
Thanks Texasmech I did it already and realized when I tighten down the rocker arm assembly when I tighten it down just enough it has a hard time turning, but if I leave it lose it cranks with no problem. Stuff done 58.5 bore, A9 cam that’s all I did and ever since have had a hard time turning everything was put back together correct, I even tried this weekend timing the go kart on another stroke but ended up bending a valve, but it cranked great on that stroke. Was able to tighten everything down and not have a problem, I came to realize every time I tighten down the rockers assembly in a cross pattern if I tighten it enough it has a hard time cranking. If I loosen it cranks fine but leaks oil out of the bottom of cylinder, it’s been a headache to be honest. New battery and new starter, checked all the ground too but still the same issue.