Bukh 20 idle adjustment

[JustinT]

Hi all
Having searched the web I keep finding the post on here about the quadrant.
Bukh DV20 Idle Adjustment
Having adjusted that, my idle is still too low.
A chap helped me service the engine a year or two ago and he definitely adjusted the idle up the top of the engine somewhere. I'm now unable to find that "adjustment screw" he was fiddling with. The Bukh manual makes no reference to it.
Does anyone know where this secret adjustment is?
Thanks for any ideas
Justin

 

[ChromeDome]

Any tips in the manual?
https://www.google.com/url?sa=t&sou...IQFnoECBQQAQ&usg=AOvVaw0jfVs7wJULYmHQXHBCHMSb

 

[JustinT]

I've not been able to find any

 

[ChromeDome]

The manual can be found on the web, e.g.
Bukh Diesel Marine Engines workshop manuals

If no help there give them a call..

UK dealer is

Proteum Ltd
Office 4&5 Firefly Road
Hamble Point Marina, School Lane
HambleSO31 4NB
Telefonnr.: +44 1202 668840
info@proteum.co.ukwww.proteum.co.uk

 

[davidmh]

Search in the PBO forum for Bukh 20 throttle adjustment, 18 August 2007 there is a detailed suggestion from Cliff. Seems you need to adjust the throttle quadrant and maybe adjust the quadrant clamp on the throttle shaft
David MH

 

[JustinT]

Thanks all!

 

[Bilgediver]

The idle adjustment is usually carried out at the speed lever on the engine This is the lever that the Teleflex connects to. There are usually two screws. One for high speed and one for tickler. Looking at the manual it appears that there ,may not be an idle screw but there is a fixed stop. This means as another poster has suggested that you adjust the position of the lever on the shaft. The shaft appears to have a square end to assist in this. Loosening the shift nut may allow adjustment.

 

[JustinT]

I have adjusted the lever on the shaft and the stop bolts. Though I may adjust again. However I was there when the chap changed the idle on a screw near the lift pump or the fuel filter, so I know it's there somewhere. Someone had cranked the idle up high as the engine is prone to stall. Now having problems keeping it running close to idle, even changing the quadrant screw positions and the place of the lever on the shaft. I suspect I have more than one issue going on with the engine and moving one screw affects the balance somewhere else. What absolute fun.

 

[ChromeDome]

Did he change the timing?

 

[Boater Sam]

Check all the silly things first like rubbish on the prop, bent cables etc.

 

[JustinT]

I'm going to go through the filters also. There is often talk of the mesh trap in the lift pump being blocked. The fuel filter has been in there a year but limited hours, very few indeed. Currently when the engine does run it's not responsive to the throttle, though the shaft on the quadrant is being moved the revs on the engine do not change. However, I haven't tested it properly as I just started it briefly with the impeller removed as the boat sits on land at low tide. I'll go back and do more tests at high tide when I have some cooling!
Last summer the engine was running just fine. There is no evidence of water in the separator. It has had the injectors serviced but there is a little white smoke.