Barrus Shire 45 fast idle.

[dixi188]

I started my Barrus Shire 45 yesterday, first time since September. 

It fired up straight away but the idle rpm was around 1200 RPM. I played with the throttle and the revs would increase but not go down. It stayed like that for aroung 10 mins. and then slowly went down to the normal 750 RPM. and behaved normally.

I have had this before when it has been left for several months.

Is this something to worry about. The engine is about 18 years old with about 4500 hrs.

[ditchcrawler]

Is the throttle cable going slack when you drop back to tick over, or is it binding in the outer

[Tony Brooks]

Left for three months or so, I think the injection pump rack probably dried out and got a bit sticky. After running a while, throwing oil about and getting warm, it simply freed off and popped back to idle. See what tomorrow holds and if it operates normally make a note to yourself not to leave it for three months without running it.

[dixi188]

Thanks for the replies chaps.

Probably not going back to the boat until March as it is 125 miles each way, so can't check the throttle cable, however, once the engine has warmed up a bit, everything is normal.

I'll see what happens next time when I plan to do a bit of boating, weather and stoppages permitting.

Cheers, Dixi.

[David Mack]

2 hours ago, ditchcrawler said:

Is the throttle cable going slack when you drop back to tick over, or is it binding in the outer

Drop the speed control to idle, then try fiddling with the engine end of the control cable. If you can get the revs to drop further that would  be strongly suggestive of a binding cable.

[dixi188]

I see where you are coming from David, but I don't think that's the problem, as the engine slowly reduced speed over about 10 seconds after warming up.

Does the rack Tony is talking about have a return spring that would move towards idle as things freed up?

I'll have a closer look next time I'm at the boat.

Thanks for your input,

Cheers,

Dixi.

[Tony Brooks]

10 hours ago, dixi188 said:

I see where you are coming from David, but I don't think that's the problem, as the engine slowly reduced speed over about 10 seconds after warming up.

Does the rack Tony is talking about have a return spring that would move towards idle as things freed up?

I'll have a closer look next time I'm at the boat.

Thanks for your input,

Cheers,

Dixi.

 

Yes and no, typically a spring to push it to maximum fuel  (flat out) and centrifugal bob weights to push it towards stop. Then a mechanical system to force it to stop (no fuel). Not sure about Barrus but some use hydraulic fuel pressure to push it towards no fuel rather than bob weights.

 

If you want more details, have a look in the Technical articles - Diesel fuel systems (BT) on www.tb-training.co.uk. http://www.tb-training.co.uk/CIsys.htm

Edited January 18, 2023 by Tony Brooks