Beta Marine 20 smoking

[kevsbox]

Hey all
Yesterday went out for a quick spin around the harbour (1st run out this year).
Before setting off I made sure water was coming out the exhaust so all seemed well. After a few minutes out we noticed grey smoke as well as the water and this got steadily worse.
We turned back and the overheating buzzer then kicked in but we got back okay.
Any ideas what the potential problem is, we seawater is going through okay so I assume the issue is within the internal water/antifreeze system, any thoughts please?

Kev

 

[Stemar]

Have you checked the fresh water cooling level?

 

[Refueler]

Check thermostat ... if its stuck partially closed - water will be passing via the bypass and engine will receive very little ... All appears ok as water is coming out exhaust - but only thing that is being cooled is the exhaust !!

In fact instead of testing - its cheap enough to just replace with new - especially if its been in for a few years ...

When did you last change oil and filters ? Grey smoke can be from burning oil ....but if engine is overheating - then oil is likely to get burnt then ..

 

[kevsbox]

Check thermostat ... if its stuck partially closed - water will be passing via the bypass and engine will receive very little ... All appears ok as water is coming out exhaust - but only thing that is being cooled is the exhaust !!

In fact instead of testing - its cheap enough to just replace with new - especially if its been in for a few years ...

When did you last change oil and filters ? Grey smoke can be from burning oil ....but if engine is overheating - then oil is likely to get burnt then ..

Filter & Oil changed last month same time as impeller and anode, but a new thermostat sounds look a good starting point

 

[kevsbox]

Have you checked the fresh water cooling level?

Did last month but I will recheck thanks

 

[kevsbox]

Have you checked the fresh water cooling level?

Water level all good

 

[kevsbox]

New thermostat has arrived just got to figure out where it goes on a Beta 20

 

[Wakatere]

New thermostat has arrived just got to figure out where it goes on a Beta 20

Under the casting on the top with "Beta" cast into it (2 hex bolts). Good luck, I'm hoping I never need to get in because I can't get mine off.

 

[paris]

My friends beta 20 wasn’t overheating, but we decided on preventative maintenance and to clean the heat exchanger out and once we removed it was 40% blocked. Good wash a scrub and popped back in, maybe yours is slightly blocked

 

[kevsbox]

My friends beta 20 wasn’t overheating, but we decided on preventative maintenance and to clean the heat exchanger out and once we removed it was 40% blocked. Good wash a scrub and popped back in, maybe yours is slightly blocked

Thanks, I will check that out this weekend

 

[kevsbox]

So I opened up the housing for the thermostat and found no thermostat...

New one fitted ready for testing after I have checked the heat exchanger this weekend

 

[kevsbox]

Thanks, I will check that out this weekend

Would I be correct in thinking the heat exchanger is in here?

 

[MoodySabre]

OM 221 20031 HE REV37 0224

 

[kevsbox]

OM 221 20031 HE REV37 0224

Thanks, page 58 was what I needed

 

[LittleSister]

On a smaller Beta (14) I found I had a long thin screwdriver that had just the right diameter shaft to poke through the tubes in the heat exchanger stack in-situ after just taking the end caps off. I've read on here others using a welding rod for the same.

So I opened up the housing for the thermostat and found no thermostat...
View attachment 177036
. . .

Had you not had overheating problems previously?

 

[kevsbox]

On a smaller Beta (14) I found I had a long thin screwdriver that had just the right diameter shaft to poke through the tubes in the heat exchanger stack in-situ after just taking the end caps off. I've read on here others using a welding rod for the same.



Had you not had overheating problems previously?

Just once, that time the sea water inlet was clogged with weed, problem went away when I jumped over and cleared the blockage. This time sea water is pumping through nicely so not the same issue. We purchased the yacht last spring and took here out 6-8 times last year with no problems at all.

 

[Supertramp]

The lower section of the aft end of the heat exchanger where the anode goes is where most debris builds up. And check for calcification in the pipe above the raw water pump. Even if the water flow appears ok.

I fitted an exhaust temperature sensor and in the 60 hours since I last cleaned the system the temperature has risen from 27 to 31. End of last season it was at 34. Which implies the blocking builds up steadily and has the effect of raising the cooling water temperature.

 

[kevsbox]

Finally got it out, now the cleaning starts

 

[paris]

Well done, that’s blocked worse than my pals.

 

[kevsbox]

After the clean up, hopefully the new O-rings will arrive today