Loss of power - help

[RichM]

I have an issue with my engine whereby I seem to have lost power. If I push it much beyond 2000rpm it splutters a little, produces a noticeable amount of black smoke (but not plumes) and just doesn't get far beyond 2000 rpm. I know Barrus Shire engines are known to be smokey but it hasn't smoked much in the past. Previously it would rev out to about 3000 rpm, not that I made a habit of doing so.

I have checked the engine oil, all looks OK. Engine temperature and oil pressure all OK. Air filter is relatively clean. Prop checked and is not fouled. 

Any idea what the issue is? The engine is a 17 year old Barrus Shire 30, unsure on the number of hours though.

Cheers

[Bee]

Sounds like fuel. Some years ago we hired a terrible boat on the Thames, it would run up to a fast tickover, any more throttle it spluttered and died, lots of black smoke, filters clogged with sludge. More recently our boat would happily run at about 1200 rpm but no faster but having a bit more experience I knew it was almost certainly fuel, sure enough new filters solved the problem. Boat fuel tanks are often a disgusting nightmare inside compared with vehicle tanks.

[MtB]

Seconded. I'd be disconnecting the outlet from the fuel filter and discharging some fuel into a clear glass or jam jar.  

You're looking for a nice free flow of fuel into the jar, and sparkling red or orange colour with no cloudiness. 

I'm suspecting diesel bug actually. 

[WotEver]

And/or clogged filters.

[mrsmelly]

yep. Restricted flow from partialy blocked fuel filter methinks.

[Rob-M]

Sounds like muck in the fuel, that was the symptoms we had with a tank of diesel bug.

[WotEver]

2 minutes ago, mrsmelly said:

yep. Restricted flow from partialy blocked fuel filter methinks.

A mate of mine ran a diesel Peugeot as a private hire taxi. He was complaining that it would rev like a new car on the flat but run out of steam on a hill. “Blocked fuel filter” says I. “Nope, I’ve replaced both of them” says he. “Sure there’s not a third?” says I. 

So he dropped it into the local dealership. They replaced the other fuel filter

[Momac]

Depending on your fuel filter you may be able to drain off a sample to see if there is any visible bug or water.  In any change the primary fuel filter.

It is possible to buy  a diesel bug test kit but it may be more cost effective to put some bug treatment in the fuel as a precaution.

I use a fuel additive as a precaution and while its use doesn't guarantee an absence of  fuel issues I do think it helps the engine run a little smoother and with less smoke on start up. There are numerous  products available. The following are examples............

https://www.clear-winner.co.uk/products/marine/

http://www.marine16.co.uk/acatalog/Fuel_Treatment_Products.html

 

 

 

[Bee]

15 hours ago, WotEver said:

A mate of mine ran a diesel Peugeot as a private hire taxi. He was complaining that it would rev like a new car on the flat but run out of steam on a hill. “Blocked fuel filter” says I. “Nope, I’ve replaced both of them” says he. “Sure there’s not a third?” says I. 

So he dropped it into the local dealership. They replaced the other fuel filter

And that illustrates just how clean the fuel needs to be to avoid problems, manufacturers would not fit all those filters just for fun.