other than the anti congealing agents, 100LL is almost identical to VP110 and C12, specific gravity is right in the middle of the two, flash point is higher etc. when are aircraft engines under the highest load? at takeoff ON THE GROUND UNDER THE SAME ... more »

my 2006 CRF 450 is ported & polished, custom web cam with lager buckets (cam so big it wouldnt clear) custom del west valvetrain, custom valve seats and guides (moldstar 90), CP platinum kit and head milled a little extra to make it 14.25:1, crank ... more »

RM's crave race gas, easiest and most cost effective option is to go to your local airfield and get some 100LL avgas, mix it 32:1 with the premix of your choice and it should be good, my experience with 100LL is that youll need one or two smaller main ... more »

best bet is to replace crank, bearings, replate cylinder and install a new top end AT THE LEAST. with all of the parts on the table it shoudlnt take a competent engine builder more than 90 minutes to tear down and rebuild.

ive had great results in running straight ATF and changing it every ride. i worked at a trans shop so i just go there after every ride and pump it straight from the big tank. its a pretty thick Dex/Merc 3 blend that costs about a 70 cents a gallon at ... more »

heli coil is NOT the right way to fix it. get a Time-Sert kit in the size you need, and youll never have to worry about it again.

every carburated honda likes just the tiniest crack of the throttle with a good healthy kick from TDC. not enough throttle to activate the AP, just enough to let that tiny extra bit of air in there. i always give it two full blips, then just barely crack ... more »

on the 4 bottom ends ive done on them, 3 of them had stress cracks running through the cases on the bottom side of the crank bearing bores. straight from one bearing, through to the other cases and into the other,

100LL avgas is nearly identical to C12, it has an anti congealing agent which wont affect you at all, it is extremely consistent and i trust it in my built RM (im an engine builder) and you can't argue with the cost. if it were in my budget, i would ... more »

either the pistons are sticking or, most likely, the caliper guide pins are sticking.

crank works inc in tempe, AZ does almost all of the sx teams' cranks. he even forges custom ones for JDR J-Star KTM, so im sure he has some good KTM stuff laying around.

they left the intake rough for a reason, it helps with fuel atomization.

i always take the edges off of the exhaust sub port area within the exhaust port, make edges nice and round, take away and casting flaws, major edges, bumps etc and polish the hell out of it.