new engine won't start, need help

[dwhitson]

My friend is just completing a '62 pan. We're having major trouble starting it. When it will start it starts easily and seems to be running ok but for the most part it just will not start up. It'll pop and backfire out the carb but not fire up. We need a good mechanic that knows pans and is willing to go over this. Bike is Freehold NJ. HELP !!!

[T. Cotten]

The most prevalent problem is airleaks at the manifold or ports.

Reassemble with clamps as close to OEM design as possible, and fresh O-rings of course (dry: no sealers or bubblegum).
Before installing the carb, pressuretest the assembly at a constant 15psi with dilute dishsoap sprayed about the manifold, and even the pancover screws over each port.

If absolutely no bubbles result, then you can go on to other variables.

[61 panman]

Are you running dual points on this? Most frequently at this point in a rebuild you have the timing 180 degrees out of phase if it exibits the symptoms you are talking about. Give us more details on it. It could be anything but odds are
#1 Timing
#2 carb or fuel supply
keep trying and remember adversity builds character
Doug
61 pan owner

[dwhitson]

thanks guys,
A quick run down. Engine was built by a shop in Emmaus, Pa.
Everything new except the cases. Started out with Electronic dist and an SU. Would only sputter and occasionally backfire but not run. Installed manual adv points distributor. Still no go, it's got STD heads with Shovel ports. Pulled the intake and carb off my running Shovel and put it on to try to eliminated the variables. I was very careful about sealing the o-rings well. Still no go. Put on a brand new S+S E, nothing. Took it to a shop in NY, they found that one of the timing gears was marked a tooth off. Switched it and got it to run every once in a while. They advised my buddy to sell it, he's (we've) got eight years into it. Two weeks ago he came out and it started on the second kick, this week it fired up after a little effort and ran for about 5 minutes, stalled and would not start. Kicked it for about two hours and gave up. When it starts it seems to run ok but it's a 25% chance of getting it going. This has been going on for about two years.

[T. Cotten]

So you never pressuretested the manifold?

[rousseau]

Make sure the push rods are adjusted properly. If its backfiring out the carb ,you may have an intake valve too tight. Also be sure that the lifters havn't been swapped for solids. I'm not that sure about pans, but it was common in shovelheads.

[Jack_Hester]

Coil? Plugs? When all the other checks mentioned have been made, swap these out. Especially, if the coil is a replica of a stock one.

Jack

[JohnR]

I had an inline aftermarket fuel filter (Glass Bowl) that was very eratic in allowing fuel delivery to the carb. It would finally let enough fuel drizzle into the carb to start the motor but then I had problems on the road including shutdown and hard restarting.