took the sons 400 to the shop to get it bored to 416, wel it ran fine but had a knock turned out one of the crank bearings had cracked. well we decided to stroke while we had the crank out. well i go to pick it up today and they can't get it to run. it would pop every few rotations of the engine but that was it. anyone have any ideas?

 

WoW a shop that does that kind of work should be able to get it started... My first guess is timing... It could be dozens of things as well. Start with the basics does it get fuel, spark, compression? Then take it from there....

 

If it's got an aftermarket rev box, I'd throw the stocker in. My White Brothers box died while I was doing my 416 kit. It took me two days and 3 cam position checks before I realized it didn't have enough spark to run. The box worked fine before I tore the engine down. Weird coincidence.

 

does it have the stock cam in it? if it does then the oiler tube for the decompression mechanism is probably missing, my kids 01' was doin the same thing as urs is doin and when we changed the cam to one with out the decompression it ran great, mine was only the second one like that that the local dealer had seen

 

it has the stock box, but it has spark and it is getting gas. kind of odd, sounds like that cam thing could be something to look at. yeah the whole thing is disapointing i took both ds's apart and put them together since friday, and there up and ready to go makes me have less positive to say about shops. these are really nice guys and honest i think they just thought they could put everything together without any real help and it bit us all in the a$$ i don't plan on the little man being disapointed.

 

I would check your decompressor.