Yanmar 6LP idle

Daniel · 15 February 2013, 10:53

bif or anyone, do you know what the tickover of the 6LP should be ? we fecked a bravo drive last year and i'm still suspicious the tickover is too high. wound it down to 500 but now i'm getting intermittent overheat alarm so obviously i need more rpm for the waterpump to do its thing properly

biffer · 15 February 2013, 11:44

750 to 800 is about right it will drop a little when in gear. I'm a little worried by overheat alarm. Are you sure it's that and low volume alarm, does the temp go up or does it just bleep every now and then

Daniel · 15 February 2013, 13:06

i'll start a new thread

Daniel · 15 February 2013, 13:08

Bif says 700-800 rpm.

I'm finding we;re clunking into a gear a little too much at those rpm's so have dropped it to 500 on tickover. It seams to tickover fine & it'll idle from cold for 30min no prob pumping but it doesnt pump a lot of water at that rpm.

Impellor is A1.

Out for a test run for 30 mins, when coming back in to mauovre now the engine is hot the exhaust alarm sounds 30 seconds after you drop into N. A quick rev in N will clear it for 30 seconds and so on we go. I understand this alarm really means we havent got any saltwater in the exhaust...

I'll try it at just under 700 and report back.

paulbrown22 · 16 February 2013, 17:00

Daniel,

I actually took note of mine this afternoon whilst out enjoying the sunshine!

My 6LP idles in neutral at about 600-650 (on the dash gauge).

I haven't touched it, so don't know if that's as it should be, or if a previous owner has tweaked it!

Regards,

Paul

Daniel · 16 February 2013, 18:06

Very useful thanks.

To be honest I think we damaged the drive when the throttle arm "ceased". Its the arm on the engine that the throttle cable clips onto which in turn activates the diesel pump. There is no bearing and after a period of non-use it can cease. I fitted a new one.

Regreatable I didnt realise what the "stiff into and out of gear" problem was immediatly. It was becase the engine was idling at 1000 rpm.

I have tweaked to 600/650 and it does idle smoother and pump a fair bit more water than at 500 but I havent had time to go for a blast and see how it reacts when up to temperature. The pay off is its notabley clukier into gear.

paulbrown22 · 16 February 2013, 19:52

I can always video my exhaust if it helps - at 600 I get a steady flow of water coming out, but not under much pressure. More like a gentle, continuous stream.

I'll double check my throttle arm if that's a potential problem area - my boat will be stored for the Summer while we're out sailing!

I'm on a Bravo III - you definitely notice it clunk into gear from neutral, but not sure that is anything untoward. I do find after having been for a long drive that it's very slow to engage between neutral and forwards whilst manoeuvring in the marina. Doesn't seem to happen when it's cold though, so wondering if the gear oil could do with a flush and a change. If not the clutch mechanism might need replacing at some stage!

Do you get any steam in your exhaust at high revs? When I open it right up, I notice a very light steam in the exhaust, which doesn't look smoky at all. I''m assume that's the result of a water injected exhaust?!

Daniel · 16 February 2013, 21:51

I think the mist / steam is normal, we are a little removed from it all in the cabin tho'

All the bravo boxes gained a reputation for poor reliability coupled to this engine so treat it gently and service regularly. Parts are very expensive.

peterwhite · 16 February 2013, 22:55

Hi Daniel. Idle speed for a 6lp should be 700 rpm in neutral. As for the drive they were slightly troublesome when used with these engines. Main problem comes from the bearings in the top on the input shaft overheating with the torque. If not already done, an idea would be to install a transom shower to try to help keep the drive cool under load. Hope this helps. Cheers. Peter