Diesel Engine Cutting Out

[Tillernut]

My recently acquired sailing vessel has a 3cyl. Kubota 12 hp diesel engine. Circa 1985/7. The engine starts first flick and goes well, although agriculturally!! However, when going from forwards to reverse, if the control is moved too quickly, the engine will cut out. Not brilliant for close quarters manouevering. I have traced the cables from the throttle and 'it' goes to a lever on the front of the engine. This lever also has another cable attached to it so the engine can be stopped by pulling a button out. Can anyone tell me how to adjust this so that the engine does not cut out or does anyone know where I can get a user manual.
Thanks in anticipation.
Terry

 

[PuffTheMagicDragon]

It is usually held that going straight from forward to astern or vice-versa, without stopping briefly in neutral, is not a good practice. Gearboxes don't like it.

Before making any adjustments I would try (in open waters) revving the motor up in forward, reducing quickly to idle and then revving up again, also in forward to see if the engine still cuts out. Chances are it won't, which means that your solution would be to simply reduce speed, stay briefly in neutral (say, counting 'one, two, three') before engaging astern.

Kubotas are excellent engines and are the basis of Beta, Nanni and several others. Good luck.

 

[PCUK]

Is your idle speed correct? If to low this could cause the problem.

 

[Malish]

Doubt it is the stop cable unless it is tight and partly engaged. As others have said, check your tickover and pause for a second in neutral when going from forward to astern. Your comment that the engine is 'agricultural' catches my eye, I don't know the model but I have a later 3cy Kubota which certainly does not emit agricultural noises so I have to ask: when did you last service the engine - air intake, fuel (& oil) filters, tappets, and ? injectors (on a mid-80's engine). In short your engine might simply be asking for some tlc

 

[Tillernut]

Thanks for the advice folks. When I said 'agricultural' perhaps I should have said unrefined. I am comparing it to the modern diesel engine. The engine was serviced within the last few months by the previous owner.
Thanks again.
Terry

 

[SailJonah]

Are your Disel injectors dirty

I had something very similar on a yanmar 3gm some years ago. started well, would run at speed, but at idle or gonig front to back it would cut out and stop.

after a lot of heartache, having the Diesel injectors serviced cured the problem for ever, cost be about £30 per injection. It also stopped the "Agricultural" nature of the engine. It became a joy to use.

 

[Refueler]

On engines such as this - there is an anti-stall device fitted to injection pump governor. It's designed to stop engine from cutting out when throttle closed quickly. If you can ease back throttle to idle and it doesn't cut out - my moneys on that having been tinkered with by 'service'.
It should never be touched by 'amateurs' as it is tricky to reset. On some engines it's part of the throttle travel / control and gets altered in error.

I don't know if your engine has had that mistake made - but I know another boat with the Beta version of your 12Hp - that was exactly what caused his to do same.

I gave the guy Perkins info about rough DIY setting of Anti-stall device and he seemed to sort his ok .... I would suggest getting hold of a service or workshop manual and checking this item. Of course it may be that your idle is set too low and Anti-Stall is not problem !