You got it backwards dude! Putting foil on the head keeps it WARMER for LONGER - and it's clearly what you want, especially this time of year- colder days mean a colder sleeve, and a harder start. heat gun is ESEENTIAL - it'll help you avoid flipping your engine into lock, and then having to slip a screwdriver on the flywheel to get it free'd and then (inherently) scratching up your piston and sleeve in doing so!
1) Get a heat gun - it's worth the money
2) Get it to as close to 200 as you can wih heat gun, then start it and let it idle for 1/2 a tank - stop engine and PUT PISTON TO BOTTOM DEAD CENTER**** (this is KEY!!! DO NOT F THIS UP! - mark the flywheel so you know where BDC is)
this is called heat cycling- by heating it up, idling, and then putting to BDC and LETTING IT COOL DOWN TO BELOW 145!!! THis is a critical part of break in- you heat the sleeve, piston etc up so they expand (heat expansion) and then contract when you let them cool. LET IT COOL BEFORE RE-STARTING - do it again for 4-5 more HALF TANKS - in other words, run 1/2 a tank, before stopping engine and letting it cool.
3) Once you've run 3 tanks (6 heat cycles) through it, now you can take it off the bench of start running it around - KEEP MAX THROTTLE SET TO 50% ON YOUR RADIO. Run another 2-3 tanks this way- let it kind load up with fuel - just give it little tugs on the throttle- LITTLE... like 5 or 6, to kinda load up the engine with fuel- then give it a nice throttle snap to burn it through- pin the throttle (remember, ths will only yield 50% on carb, cause you set your radio that way!) ad hold it pinned for 2-3 seconds solid, so it burns through the fuel - blip it around the street this way - keep checking your temp- it's GOTTA be 200 or more for this - if its running at 160-170, lean out the main jet a bit then- to get it to 200.
4) Finally, adjust radio to let it go 100% throttle- you DONT HAVE TO PIN IT, just run it around, treating the throttle GINGERLY, but DO load it up and then give it some nice gas and run it aornd this way. REMEMBE TO KEEP HEAT CYCLING IN BETWEEN RUNS - PUT THE PISTON TO BDC AND LET IT COOL DOWN!!!
After this, you should basically have run 6-9 tanks through or so, and this is enough- from here you can run it how you want, and I always found engines tend to run better at 220-230, rather than 200... but i guess it depends on the mill..
good luck
Originally Posted by
ezveedub
First off, you got a large discrepency in your temp gauges. You need to scan into the head area at the glowplug and move it around to get the highest reading. Sometimes you think your point straight in, but your off and most likely reading a cooling fin.
As for the first tank of break-in, I heat gun the engine to 200+F (160 is good enough with a hair drier if you don't have a heat gun), then run the engine at slightly higher idle and read the temps. Get the car off the ground so the wheels can free spin if needed. I monitor the temps and adjust throttle linkage and idle screw then the low needle first set to a rich setting but keeping the temps up around 180F or more but no more than 245F. Wrap foil on the head as the outside temp your running at with a rich setting will make the engine cold. Keep watch on the temps, because the engine will run richer as it breaks-in and will start to bog and get cold, so you'll need to start leaning each needle slightly as you go throough more tanks of fuel. I suggest maybe to install a hot glowplug so the engine will stay running under rich conditions when break-in your engine.