Won't start after big bore install
 

Finished reinstalling my 98" Big Bore Kit from Kirby at VeeTwin Racing. Including the heads, cam and new ignition. Added fuel and oils and went to crank her up. She turns over and every once in a while it makes a loud pop out of the pipes or spits out of the carb. It's getting spark and fuel. I checked the connections and it all seems to be buttoned back together, just won't fire up. Any hints or tips to check for? 2001 Fatboy, carbureted Twin Cam.

Your push rods may not be adjusted correctly if its spitting out the exhaust and intake. The valves are not closing all the way.

compression test or leak down test will tell you.

I don't want to assume anything so please don't be offended, but that happened on one of my friend's builds and he simply had the spark plug wires connected to the wrong coil outlets. Reversed them and she fired right up.

If it's NOT that simple and the pushrod thing doesn't pan out, did you make any timing adjustements via any Fuel Management programming that you did for the new build?

Start with the simple and inexpensive things, move up to the more complex and expensive things.

My .02

Very common and very easy to do. If this is not the issue, what ignition are you running and what ignition map?

I told him to check the wires,its pretty what it sounds like when their backwards

When he said the "every once in a while she pops.." that was the first thing I thought of too. Been there, bought the T-shirt...

mee too,the first twin cam I ever did(around 2001 or so).have the thing apart about 10 times to check cam timing,then I was laying in bed and thought "man,these things are single fire",went down to the shop in the middle of the night,switch the wire around on the coil,bike fired right up and ran like a dream

Easy to flip/flop the wires if you don't do it all the time.
Scott

When I did that it wouldn't fire at all, which absolutely convinced me that it was something else.

I did it too. Check the plugs also to make sure you didn't drown them.