Gear oil looks like milkshake

[nicksharpe]

Morning. Just changing gear oil on my 3.3hp 2-stroke Mercury outboard and the oil which came out looks like chocolate milkshake. No sign of any water, just milky chocolate oil.

Having YouTubed it I'm going to replace all the seals. This kit seems to be the very thing, do you guys agree? https://www.ebay.co.uk/itm/273136198559

Nick

[willk]

All the seals!

Have you been servicing this leg yourself? I only ask as it could be something like a poor drain washer fit. The washers should be replaced after each lube job. I bought a brand new outboard that was PDIed and supplied without the bottom screw washer fitted. Luckily I spotted it. Fishing wire around the prop shaft would do it too - any history there?

If you're happy pull all that stuff out then go for it. Your proposed vendor has something of a reputation on here - some get, some don't.

[Fenlander]

Totally with Willk. Replace the oil (use marine type as this is happier in an oil/water mix) and use new seals then monitor. Do not use generic plastic seals but a fibre type that close fits the thread of the plug. Do not over tighten as that can splay the seal out and allow water ingress.

[nicksharpe]

Thanks both. I got the engine from a dealer as an aux about 2 years ago, it's probably only run 90 minutes in that time, mostly in the tank just to keep it in working order. So this is the first time I've looked at the gear oil.

As you say I'll change the oil, replace the seals and keep an eye on her.