Troubles Dad

iTrader: (204)

30 degrees is a heat wave as for breaking in the motor, wrap it in tin foil, several layers around the block and head, an old sock around the head will help also, try to keep it at 200 degrees, driving it around for a few minutes and then shut it down, because by then your fingers will be frozen, take it inside and repeat, leaning it out each time, when you get ready for race tune remember to richen it up as the track will hopefully be warmer than 30 degrees, I have broken in several race motors this way and had great success, it will take more time in the winter due to the outside temps and have not seen any bad issues with one yet I don't think I would even try to break it in if the temps were in the teens, above zero

jamminnay

iTrader: (11)

i broke one in when it was in the 30īs and it turned out alright.. foil is your friend!

SPEEDSKI

It really doesnt matter if its cold. Obvioulsy a heat gun is great to get it started, if you are using a bench, keep the heat gun on it. Dont run lean and don't run it too rich either. The sleeve is brass and it will expand faster that the aluminum piston anyway. Just get it running slightly rich and hopefully have a load on the motor. Heat gun is no different than it being 90 degrees outside.

markt311

iTrader: (34)

I just broke in a motor and it was low to high 30's the whole time. It came out fine, I wrapped foil around the head and heated it to 150 with a hair dryer. let it set on the starter box at idle. get it up to 180-200 for 4 minutes, then shut it down by bumping the flywheel or covering the exhaust, repeat that 5 times. Then do the same thing but get it up to 200-220 and let it idle for 6 minutes then shut off, do that 5 or 6 times. Then you can run it around a little, no more than 1/2 to 3/4 throttle, keep the temp at 190-220 using foil on the head, run for 5 or 6 minutes then shut it off, do that 5 times. Then you can start tuning for racing, let the motor cool to at least 80 between heat cycles, it takes a long time but it will save the pinch. It took me a little over a week to get all my heat cycles in b/c of work and snow and rain, but the first race last weekend the motor ran like a champ, I was having a hard time keeping the temp up during the racing cause the building the track was in was only about 45 but it worked great.
Good Luck