Jump to content
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
scotsdgpiper

Thornycroft engine fault

Featured Posts

First thought is starter motor.

Its almost as if it spinning but not engaging - is the dog getting thrown forward ?

 

Take the starter off and connect it to 12v and see if it is working (is the dog getting thrown forward ? and check the teeth and see if they are damaged / stripped)

Share this post


Link to post
Share on other sites
3 minutes ago, scotsdgpiper said:

Alan,

 

Thank you!! , that is my next task next week, just getting hit with this storm and actually starting to feel seasick lol

Make sure you have a can of WD40 in case the dog is a 'bit stuck'.

Share this post


Link to post
Share on other sites

Wot they say above.

The engine looked a bit mucky and lots of rust around which - if the boat has been 'standing around'  for a while could gum up the starter and stop the cog engaging with the flywheel ring.

The batteries sound great - so that's one item out of the way.

If  you're not familiar with engne starters - there's a gear wheel on the starter shaft which spins when you run the starter motor.

The shaft has a helical spline - so that when the motor shaft turns the gear 'slides' up the shaft , engages with the engine flywheel and rotates the crankshaft.

If there's rust / gunge / w.h.y on the shaft the gear wont slide - and nowt happens - other than the noise as heard in the video.

It doesn't help if the weather's cold as that add to the gumming up situation.

 

Not a good explanation but it migh help in the understanding of the process.....

Share this post


Link to post
Share on other sites

May be a slipping one way clutch located behind the pinion, try to turn the armature in both directions by the pinion, you may find it won't turn the armature in either direction. A better test is to clamp the motor in a decent vice and wire up, then try to stop the pinion with a length of 2 x 3 or so timber.

Share this post


Link to post
Share on other sites
24 minutes ago, Paulhvtr said:

Gives whack with a piece of wood. Always worked on my old Triumph Dolomite 

And if that doesn’t work the piece of wood wasn’t big enough...

Share this post


Link to post
Share on other sites
Just now, WotEver said:

And if that doesn’t work the piece of wood wasn’t big enough...

⬆️ He knows 

  • Haha 1

Share this post


Link to post
Share on other sites
4 hours ago, Alan de Enfield said:

Take the starter off and connect it to 12v and see if it is working (is the dog getting thrown forward ? and check the teeth and see if they are damaged / stripped)

For the OP, if you do do this note the following.

With the starter off the engine, you'll need to bolt the battery black earth lead that goes somewhere on the engine to the starter motor body via one of the bolt holes as well as the big battery 12V+ lead to the main tag and any other wires. The kick when the starter turns is considerable. Be ready for it, preferably by having the starter held in a vice. Be careful with the wires. Any short circuits will flow very high currents and produce big fat sparks.

Jen

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.