Compression test

This forum is about the Fordson Dexta, Super Dexta and Petrol Dexta.
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Not Quite Blue Yet
Posts: 16
Joined: Fri Mar 02, 2012 5:32 pm
Location: South Wales uk

Compression test

Post by Dexydog64 »

Still having no luck starting the Dexta. Carried out compression test, not the best results.
No1 140 psi added a drop of engine oil to top of piston tested again 220 psi :(
No2 300 psi Happy enough 8)
No3 100 psi added oil 120 psi :( Not good.
Another question
How much of a spirt of diesel should come from injector feed pipe, just getting a small spit of diesel.
Which of the engine rebuild kits is the best? Guess its time for a rebuild after 56 years.

sky blue
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Posts: 292
Joined: Sun May 06, 2012 9:20 am
Location: Ireland

Re: Compression test

Post by sky blue »

a small spit of diesel intermitally from each injector as engine is turnned over
is normal, cant really help with engine kit i suppose they all much the same
someone eles on here may know which is best type to go for , good luck either way
sky blue

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Location: Somerset UK

Re: Compression test

Post by Nick »

You may find when you take the head off that it needs the head re-conditioning and the bottom end is ok :D
Oh yay, look, another seized bolt! Lets get a hammer.....and some kano.....and some cider!

True Blue
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Joined: Tue Sep 22, 2009 8:21 pm
Location: Spalding, Lincolnshire, England

Re: Compression test

Post by marcusgs »


It doesn't matter how much diesel you have getting in, with those compression figures you're never gonna get started!

Whip off the head and check the valves and seats, if they're ok, it will be out with the pistons and liners I'm afraid...

Bepco do the best engine kits, if you can find them..


tom lad
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Location: Preston, Lancashire. UK.

Re: Compression test

Post by tom lad »

I agree whip off the head , it is easy access on the dexta once the bonnets off.
do the injectors protrude thru the bottom of the head once its off ,so don't put it down on the bench , right way up because it will damage them , put it on its side or remove them first .or am I thinking of a different engine all together :oops: :oops:

have a look at the valves then report back :wink:

loads of helpful knowledgeable chaps on this excellent forum to help

on the plus side at least there only 3 cylinders to worry about
Some mornings I wake up grumpy, but most mornings I let her sleep in.

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