The verbs in this list double their final consonant according to the rules in verblist, chapter 3: verb-irregularities.
abet
abhor
admit
airdrop
allot
annul
appal
backslap
beget
begin
canvas
commit
compel
concur
confer
control
curet
decontrol
defer
deter
disbar
disinter
distil
eavesdrop
embed
emit
enrol
enthral
entrap
excel
expel
extol
forbid
forget
fulfil
gravel
handicap
hiccup
impel
incur
infer
input
instal
instil
inter
kidnap
manumit
occur
omit
outbid
outfit
outwit
overbid
overrun
patrol
permit
pettifog
prefer
propel
readmit
rebel
rebut
recap
recur
refer
refit
regret
remit
repel
reset
rewrap
sharecrop
submit
transfer
transmit
trepan
unbar
upset
worship
zigzag