Bukh starter fails to lock in

[b4bu]

I have a ~1987 Bukh DV20 engine, where the starter motor works fine, except the ratchet on the drive shaft fails to lock in. Does anyone know how this can be fixed. Or, if not, if it's possible to obtian and replace just the rachet device within the drive gear on the starter motor?

Tnx,

B4bu

 

[clyst]

Sounds as if it just a bit sticky . have the same trouble with my Bukh 24. Spray the starter pinion area with good old WD40 -----Works for me .

 

[pvb]

Pre-engaged starter...

It's a pre-engaged starter, not an inertia starter. If it's not engaging properly, there's a problem with the solenoid actuator. This should be repairable by any good auto-electrics place.

PS Didn't you ask this question over 2 years ago in another place?

 

[gandy]

Re: Pre-engaged starter...

On normal pre-engaged starters there's a part they call "drive unit" or similar behind the pinion. That's a wearing part, and its failure can cause the motor not to drive, or to be thrown out as the engine turns over. We had one fail on a tractor starter, and when I overhauled the Volvo starter last year we replaced the part as a precaution.

 

[b4bu]

Re: Pre-engaged starter...

> PS Didn't you ask this question over 2 years ago in another place?

I am impressed. Yes, the question was indeed posted at boatdiesel.com in may 05. Not by me, but i cutpasted/stole most of it. There was only one reply to the original post and only paying members can read it. No good. Much better here.
--
babu

 

[Gin]

Had a similar problem with my DV10 but had to use a a very narrow strip of emery cloth to smooth the shaft on which the dog slides, and then a light oil after washing off the emery dust.

Be careful not to hold the ignition key on 'start' for too long, in the hope it will work as the cable from the solenoid to the key switch will get very hot and could burn out

 

[iacle]

If there's a click & a whirring noise -as the shaft turns, but the gear doesn't engage, it's probably the clutch assembly behind the gear. It's available from Bukh. I changed mine at the beginning of the season - it's fairly easy, but not particularly cheap!

 

[Poignard]

Anyone know a cheaper source for these clutches than BUKH? They are manufactured by Bosch.

 

[gandy]

[ QUOTE ]
Anyone know a cheaper source for these clutches than BUKH? They are manufactured by Bosch.

[/ QUOTE ]If the whole starter is Bosch, then a decent auto electrical place should be able to do it. When they overhauled our Volvo MD7A starter (also Bosch) the parts had to be ordered, but it was a quite routine job for them.

 

[b4bu]

> If there's a click & a whirring noise [...]

It certainly is. It goes 'click - whiirrrrrr', the gear not engaging. However, if I try a few times it suddenly do engange with a very loud screeching sound. My guess is that this sound is from the small gear almost but not quite engaging for a second or so before fitting in. Or it could be the clutch thingy within the starter having a hard time? Anyway, this typically happens when the motor hasn't been used for a while.

From the above posts (tnx, btw) the solution seems to be to dismount the starter and try to find someone who can overhaul it. Or replace it.

Bu there is one thing I don't understand here. If the starter is 'pre-engaged', shouldn't the small gear engage first, before the motor starts spinning?
--
babu

 

[gandy]

A pre-engaged starter spins the motor at low power when the solenoid is energised. That's to make sure the teeth can mesh with the flywheel as the pinion moves into engagement. When the solenoid reaches the end of its travel, which means the pinion must be fully meshed, it closed the main contacts to power the motor up fully.