Evinrude E50RNLIB

Srednuasdivad · 04 May 2020, 20:22

Engine starting fine but running rough, good balanced compressions ..130's but....
Sign of oil in the telltale cooling water and oil and water vapour from the prop exhaust....
I'm guessing a gasket somewhere but can anyone help.
Ex auto engineer but first marine outboard.
Thanks guys..

Allye · 05 May 2020, 06:34

That’s an old 2 stroke isn’t it?

Srednuasdivad · 05 May 2020, 09:54

Yes it is. Came off the back of a Coastguard Rib a few years ago now.
Originally belonged to the RNLI but was passed on to Coastguard, as many things have been over the years.... 🙂,.
Came to me a year or so ago.
Would like to get it out on Loch Ness this summer and round up Nessie for a photoshoot 😂.
However, as mentioned in my post, I have a problem....
Any thoughts?

Allye · 05 May 2020, 09:56

How long have you run it for? Residue in the water jacket maybe?

Silly question and sorry if it insults! Are you running it on muffs not a dirty tank?

Srednuasdivad · 05 May 2020, 10:11

Only been running it up for 5-10 minutes at at time.
Hands up, I HAVE been running it out of a constant feed tank, not muffs, so that would likely pick up any oil in the exhaust and feed it back through the cooling water and out of the telltale, yes?
So, tell me about this water jacket residue please? How does this occur?
Seriously, I have a very limited experience with outboards so please feel free to speak what might be very obvious to you. I promise I will not feel insulted.

Allye · 05 May 2020, 10:40

I’d suggest it’s picking up the dirty residue from the exhaust in that case as you’ve deduced. Especially a smokey old 2 stroke such as that one!

Ref water jacket, I only thought it could be gummed up with crap if it’s been sat a while and cleaning it out with use. If you’ve been on the spanner’s for a while this thing will be no issues to you at all! Glorified strimmer.

Srednuasdivad · 05 May 2020, 11:11

Cheers my friend. Next stop muff shop.
Ran a smokey old 40 Johnson two stroke twin for a few years over 30 years ago. Hand pull on that one, still got the duff shoulder.
So, good compressions, plenty of water through telltale, doesn't feel like the head gasket. Anywhere else the oil could be coming from?

Allye · 05 May 2020, 12:11

I’d get it on the boat and try it out. Might be making mountains out of mole hills. Set of muffs is a tenner!

Last Tango · 05 May 2020, 12:19

Remember

This is an old pre-mix two stroke so you can't have an "oil leak". Apart from the gearbox there's no unmixed oil anywhere to "leak" no oil galleries etc.
I'm guessing it's the oily exhaust residue because the engine's not running properly......Basics. fuel/oil mix right,? fuel fresh?, carbs needing cleaned or ignition issue. Another one I've seen is the fuel pump diaphragm damaged and neat fuel/oil being drawn through the vacuum drive tube for the pump into the crankcase.

Srednuasdivad · 05 May 2020, 16:22

Thanks Allye, can't get it on the Loch just now as under lockdown.
Flush muffs on their way.
Will let you know.
Grateful for you help.

Srednuasdivad · 05 May 2020, 16:26

Thanks Last Tango.
Plenty for me to be getting on with there.
Bit stuck for slipping just now as Scotland is under lockdown like the rest of the UK but will try running with the muffs so I can check out your suggestions.

Ribtecer · 05 May 2020, 19:05

A bit of oil sat around the water jacket system does not sound like a bad thing to me, especially over the winter months.

I might get a big water bucket and add a bit of oil before winter.