Burning Oil - Decarb?

[Bayhouse2]

My DF300's (~1k hours) are both burning oil, at least a gallon in ~50hrs. At the last service, the tech told me there was carbon on the water pump housing and very black oil. I don't use fuel treatment and for at least the last 2 years have been using ValveTec gas. Before, it was a mix of ValveTec and regular - sometimes mixed). I do a lot of trolling but also very long runs at 4600-4900k RPMs.

Could carbon build up cause the oil burn and if so, what do I do to remedy the problem?

[tsturm]

My DF300's (~1k hours) are both burning oil, at least a gallon in ~50hrs. At the last service, the tech told me there was carbon on the water pump housing and very black oil. I don't use fuel treatment and for at least the last 2 years have been using ValveTec gas. Before, it was a mix of ValveTec and regular - sometimes mixed). I do a lot of trolling but also very long runs at 4600-4900k RPMs.

Could carbon build up cause the oil burn and if so, what do I do to remedy the problem?

Try some Yamaha ring free according to the directions. Good stuff

[Moonlighter]

When was the last time you had the valve clearances checked?

Did the tech not suggest that to you???

[Bayhouse2]

When was the last time you had the valve clearances checked?

Did the tech not suggest that to you???

He did not and the valve clearances have never been checked. I remember asking him about this a while back (based on the service manual) and his attitude was 'if it ain't broke, don't fix it'. I think in addition to a fuel additive i'm going to start, i'll have a tech check the valve clearances.

[artdf175]

https://www.suzukioutboardforum.com/...-df175-results

see if you can gather anything from this
Art

[Moonlighter]

He did not and the valve clearances have never been checked. I remember asking him about this a while back (based on the service manual) and his attitude was 'if it ain't broke, don't fix it'. I think in addition to a fuel additive i'm going to start, i'll have a tech check the valve clearances.

Make sure it is a tech that is qualified and EXPERIENCED in Suzuki 4 strokes.

Before you give them the job, ask if they own the special tool required if shims need to be replaced and if they have the Suzuki shim kit. Both are an indication of someone who knows what they are doing.

[Bayhouse2]

https://www.suzukioutboardforum.com/...-df175-results

see if you can gather anything from this
Art

What happened in Part 2??

Good (but scary) information. I've owned the engines since new and know the break-in was done properly. They only recently started burning oil and that's why I think (hope) is only carbon build up. The tech did report an accumulation of carbon on the water pump during the last service but i'm also going to have the valve clearances checked. That was the only thing in the service manual I skipped and I hope it doesn't come back to bite me.

[Bayhouse2]

Make sure it is a tech that is qualified and EXPERIENCED in Suzuki 4 strokes.

Before you give them the job, ask if they own the special tool required if shims need to be replaced and if they have the Suzuki shim kit. Both are an indication of someone who knows what they are doing.

Good advice and I'm now in a location where I should have options for mechanics. This will help me pick one, thank you!

[artdf175]

https://www.suzukioutboardforum.com/...%C2%96-results

Part 2 not related to the oil loss ( but because you ask!!!)

the other thing to mention: checking the valve clearances:
It is not that difficult of a job to check the clearances just
a good feeler gauge
just follow the instructions in the engine service manual
Art