Here’s my translation

Alan

Síðan kaupir Kjartan skip hálft að Kálfi og gera helmingarfélag.
After-that Kjartan buys half (the) ship from Kálfr and (they) make a joint-company (with equal shares).

Skal Kjartan koma til skips þá er tíu vikur eru af sumri. Gjöfum var Kjartan út leiddur frá Borg.
Kjartan shall come to (the) ship when (there) are (ie have passed) ten weeks of summer. Kjartan was lead out (ie sent off) from Borg with gifts.

Ríða þeir Bolli heim síðan. En er Ólafur frétti þessa
They, (Kjartan and) Bolli ride home after-that. But when Ólafr heard (got wind) of this

ráðabreytni þá þótti honum Kjartan þessu hafa skjótt ráðið og kvaðst þó eigi bregða mundu.
change-in-circumstances (break from the allotted life-course), then Kjartan seemed to him to have hastily devised (decided) this and (but) declared-of-himself nevertheless (that he) would not reproach (bregða, Z6) (him).


Litlu síðar ríður Kjartan til Lauga og segir Guðrúnu utanferð sína.
A little later Kjartan rides to Laugar and says to Guðrún (about) his journey-abroad.

Guðrún mælti: "Skjótt hefir þú þetta ráðið Kjartan."
Guðrún spoke: “Hastily have you decided this, Kjartan.”

Hefir hún þar um nokkur orð þau er Kjartan mátti skilja að Guðrún lét sér ógetið að þessu.
She has some words about that (see þar um, Z3), from which (?) Kjartan might understand (discern) that Guðrún was displeased (see úgetinn, Z2) at this.


Kjartan mælti: "Lát þér eigi þetta mislíka. Eg skal gera annan hlut svo að
Kjartan spoke: “Let this not displease you (Don´t go ballistic!). I shall do some-other (see annarr, Z4) thing so that

þér þyki vel."
(it) should seem well to you (ie to appease you).”

Guðrún mælti: "Entu þetta því að eg mun brátt yfir því lýsa."
Guðrún spoke: “Fulfil (desist, enda, Z2 + þú) this because I will at-once make that known (see lýsa yfir e-u, Z4).”

Kjartan bað hana svo gera.
Kjartan bade her to do so.

Guðrún mælti: "Þá vil eg fara utan með þér í sumar og hefir þú þá yfir bætt við mig
Guðrún spoke: “Then I want to go abroad with you in (the) summer and you (will) have then made up (atoned) to me

þetta bráðræði því að ekki ann eg Íslandi."
(for) this rashness (hasty-talk) because I love (unna, Z2) not Iceland.”

"Það má eigi vera," segir Kjartan. "Bræður þínir eru óráðnir en faðir þinn
“That cannot be,” says Kjartan. “Your brothers are unsettled but (and) your father

gamall og eru þeir allri forsjá sviptir ef þú ferð af landi á brott og bíð
old and they are deprived of all foresight if you journey away from (the) country -and (so) wait

mín þrjá vetur."
for me three winters.”

Guðrún kvaðst um það mundu engu heita og þótti sinn veg hvoru þeirra og
Guðrún declared-of-herself (that she) would promise nothing concerning that and (it) seemed their own way for each of them (ie they would have to agree to disagree) and

skildu með því. Reið Kjartan heim.
(they) parted with that. Kjartan rode home.

Ólafur reið til þings um sumarið. Kjartan reið með föður sínum vestan úr
Ólafr road to (the) Thing during the-summer. Kjartan rode with his father from-the-west out of

Hjarðarholti og skildust í Norðurárdal. Þaðan reið Kjartan til skips og
Hjarðarholt and separated in Norðurárdalr (North-River-Dale). From-there Kjartan rode to (his) ship and

Bolli frændi hans var í för með honum. Tíu voru þeir íslenskir menn saman alls
Bolli, his kinsman, was in company (on the journey) with him. They were ten Icelandic men (persons) all together

er í ferð voru með Kjartani og engi vildi skiljast við Kjartan fyrir
who were in the journey (ie travelled) with Kjartan and none wanted to part with Kjartan for

ástar sakir. Ríður Kjartan til skips við þetta föruneyti. Kálfur Ásgeirsson
reasons of affection. Kjartan rides to (the) ship with this travelling-band, Kálfr Ásgeirr’s-son

fagnar þeim vel. Mikið fé höfðu þeir utan, Kjartan og Bolli. Halda þeir nú á
received them well. Much property had they (for the journey) abroad, Kjartan and Bolli. They are now busy with (see halda á, Z.iii)

búnaði sínum og þegar er byr gaf sigla þeir út eftir Borgarfirði léttan byr og góðan
their preparations (for the voyage) and as-soon-as (it) gave a fair-wind, they sail out along Borgarfjörðr (with) a light and good breeze

og síðan í haf. Þeim byrjaði vel, tóku Noreg norður við Þrándheim,
and after-that out-to sea. It blew well for them (they got a fair wind), reached Norway to the north close to Þrándheim (Trondheim),

lögðu inn til Agðaness og hittu þar menn að máli og spurðu tíðinda.
sailed (leggja, Z10) in to Agðanes and met there men (persons) for speech (ie obtained speech with men, see hitta at máli, under máli, Z3) and asked for tidings.

Þeim var sagt að höfðingjaskipti var orðið í landinu. Var Hákon jarl frá fallinn en
(It) was said to them that a change-of-rulers had occurred in the-country. Earl Hákon was fallen from (power? or life?) but (and)

Ólafur konungur Tryggvason til kominn og hafði allur Noregur fallið í hans
King Ólafr Tryggvi’s-son (was) come to (power) and all Norway had fallen into his

vald. Ólafur konungur bauð siðaskipti í Noregi. Gengu menn allmisjafnt undir það.
power. King Ólafr ordered (bjóða, Z4) a change-of-faith in Norway. Men (persons) went under (reacted, responded to) that in-all-different-ways.

Þeir Kjartan lögðu inn til Niðaróss skipi sínu
They, Kjartan (and co) sailed (directed) their ship in to Niðarós.