Kamp ocağına yeni gaz kartuşu taktık.

The -na part is the dative case, which often means to, into, or onto.

Here, kamp ocağına means something like to/onto the camping stove. The gas cartridge is being fitted onto the stove, so Turkish uses the dative.

Breakdown:

• ocak = stove
• ocağı = its stove / stove of ... / stove (as part of a compound)
• ocağına = to/onto its stove

So kamp ocağına is onto the camping stove.

Because kamp ocağı is a noun compound in Turkish.

In Turkish, compounds like camp stove, car door, school bus, etc. often take a special compound marker on the second noun.

So:

• kamp = camp
• ocak = stove
• kamp ocağı = camp stove / camping stove

That -ı in ocağı is not the accusative here. It is the compound/possessive-type ending that commonly appears in Turkish noun compounds.

Then the dative is added:

• kamp ocağı
  • -na → kamp ocağına

Also notice that k changes to ğ when a vowel-starting suffix is added:

• ocak → ocağı

For the same basic reason: gaz kartuşu is also a noun compound.

• gaz = gas
• kartuş = cartridge
• gaz kartuşu = gas cartridge / gas canister

The -u is part of the compound form, not necessarily the accusative.

So in this sentence:

• yeni gaz kartuşu = a new gas cartridge

This is the object of the verb, but it is still indefinite.

Because if it were accusative, you would normally see an extra accusative ending on top of the compound form.

Compare:

• gaz kartuşu = a gas cartridge
• yeni gaz kartuşu taktık = We fitted a new gas cartridge.
• gaz kartuşunu taktık = We fitted the gas cartridge. / We fitted that gas cartridge.

So:

• kartuşu here is part of the noun compound
• kartuşunu would be the compound form plus the accusative, making it a definite/specific direct object

This is a very common point of confusion for learners.

Because Turkish verbs often already show the subject.

taktık means we attached / we fitted / we installed.

Breakdown:

• tak- = attach, fit, put on, install
• -tı/-ti/-tu/-tü = past tense
• -k = we

So biz is not necessary. You could say Biz kamp ocağına yeni gaz kartuşu taktık, but it is usually omitted unless you want emphasis or contrast.

It comes from takmak, a very common Turkish verb with several related meanings:

• to attach
• to put on
• to fit
• to install
• to insert

In this sentence, the most natural English idea is something like:

• We fitted a new gas cartridge onto the camping stove
• We installed a new gas canister on the camp stove

So takmak is broader than any single English verb.

Because Turkish is usually an SOV language: Subject – Object – Verb.

So the basic order is often:

• (We) [camp stove + dative] [new gas cartridge] fitted

That is why taktık comes last.

Turkish word order is somewhat flexible, but the verb very often stays at the end in neutral sentences.

Turkish often places background information, location, direction, or context before the direct object.

So this order is very natural:

• Kamp ocağına = onto the camping stove
• yeni gaz kartuşu = a new gas cartridge
• taktık = we fitted

A different order is possible, such as Yeni gaz kartuşu kamp ocağına taktık, but the original sentence sounds very natural and neutral.

This is due to a common sound change in Turkish.

When some nouns ending in -k take a vowel-starting suffix, the k often softens to ğ.

So:

• ocak
• ocağı
• ocağına

This is a normal pattern and worth getting used to.

Other words can show similar changes.

yeni means new, and Turkish adjectives do not change form to agree with the noun.

So:

• yeni kartuş = new cartridge
• yeni gaz kartuşu = new gas cartridge

No gender, no plural agreement, no case agreement on the adjective itself.

That is much simpler than in many European languages.

Yes, but it would change the meaning slightly.

• yeni gaz kartuşu taktık = We fitted a new gas cartridge.
• yeni gaz kartuşunu taktık = We fitted the/that new gas cartridge.

The version in your sentence sounds more like introducing a new item, not pointing to a specific already-identified one.

Structurally, Turkish uses a form that historically looks possessive, but in modern usage it often just functions as a normal noun compound.

So kamp ocağı is best understood as:

• camp stove
• camping stove

not necessarily the stove of the camp in a literal ownership sense.

This is a very common Turkish pattern:

• araba kapısı = car door
• okul bahçesi = school garden
• gaz kartuşu = gas cartridge

So it is better to learn it as a compound pattern rather than translating it too literally every time.